Sp apparently after having the entire engine looked over, nothing big is standing out. Lifters were put back to stock FMS while the lower intake was off and the valvetrain is back quiet again but all new gaskets installed, egr and iac blocked off to check for internal problems, yet the engine still doesn't run right. Timing verified at 10 degrees, cylinder blowby test/crankcase pressure showed a max of 4cfm on 5500rpm snapped throttle runs. Car looked over by a performance shop and a machine shop that also has their own dyno. Oxygen sensors are switching normally but a wideband shows way lean when the engine is running poorly.
37psi fuel pressure, yet warm open loop runs incredibly lean. The popping through the intake is gone but the engine falls on its face in warm open loop for a second or two before it always corrects itself. Car has the mass air conversion done which helped nothing. Vacuum is at 16in at warm idle, idle shakes the entire front clip in warm open loop - smooth as the stock SO motor in closed loop. Fuel economy is still down at 28mpg compared to the previous similar motor that gave me 30-31. Other motor also ran incredible all around compared to this one which runs like the 225,000 mile SO motor it was supposed to replace when in open loop. Plenty of power in closed loop though. TPS, ECT, ACT, MAP/BAP sensors new, mass air sensor as clean as it'll ever get.
Anyone have any ideas on where to look next? I have a wideband coming so I can monitor this more closely myself but I am out of ideas, as are both shops. The shops tell me to just get it tuned for more fuel in open loop but that isn't a cure...
Sounds kind of like the same problem I had with my 1988 Cougar XR-7 after I converted it to Mass Air. After months & $$$ later of trying to figure out what's wrong with the engine, I found out that you have to get an air adjuster. Which is a DIGITAL ELECTRONIC solution that allows you to adjust your air-fuel ratio rich or lean, to accurately match the Mass-Air Flow Sensor calibration to your engine. The Air Adjuster gives you the adjustability over the air/fuel ratio that you don't currently have on late-model, computer-controlled engines. Eliminates rich/lean conditions, hunting/surging idle and drivability problems resulting from a mis-matched Mass-Air Flow Sensor signal. Go to mass-air.com to get more info & you can purchase the Air Adjuster there for $179. Hopefully this helped.
Here's a question but what's your fuel pressure? Also what injectors are you running? 19s or 24s? What MAF are you using?
When running with the vacuum line disconnected. 19lb injectors with a stock 55mm mass air meter and 60mm throttle body. Fuel pressure isn't 40, but its within spec and shouldn't be causing this problem at idle.
I know you said problem continues since switching to mass air, but your issue sounds similar to Ronnie's(chrome302jr)problem...
(BTW he's fine and still has his Bird, just has other things going on in his life)
Anyway he had some very lean issues(18:1 on wideband) and it stumbled badly... He had tried about everything else, so we tried my MAF with no help... Finally tried my A9P EEC(believe his was same), which fixed it... Soooo if you can borrow a EEC, may want to try that...
Also Paul posted recently about a continual rough running issue and had found the o2 sensor wires were reversed(right to left bank)...
I'll find one and give it a try (Mine's an A9P also). I don't see why oxygen sensors being crossed would affect open loop though. Is there even a decent way to know which goes on which side without trying to just keep them separated when initially pulling the motor?
Is your car a stock 5.0L or do you have some high performance parts? My cougar is stock other then shorty headers & when I converted it to Mass Air the engine started to spit & sputter & hesitates when you push the gas, like ther'es a vacuum leak. And it has a rough idle. The company i bought the Mass Air kit from said the conversion kits are for HO motors and that I needed to get an Air Adjuster because the Mass air kit is set up to read signals for a HO motor & that is why your car is runnin to lean or to rich. And the Air Adjuster allows you to adjust your air-fuel ratio rich or lean, to accurately match the Mass-Air Flow Sensor calibration to your engine. The Air Adjuster gives you the adjustability over the air/fuel ratio that you don't currently have on late-model, computer-controlled engines. Eliminates rich/lean conditions, hunting/surging idle and drivability problems resulting from a mis-matched Mass-Air Flow Sensor signal.
why would you convert a stock car to mass air?
I'm confused about all this - how does this car even run? Mass air requires a mass air computer. The mass air computer is setup for the HO firing order. The HO firing order would not work with the SO's camshaft. Therefore, there is no way this engine could run with the stock camshaft that came in these cars.
I'm also not sure what this "Air Adjuster" is supposed to even do. As long as the mass air meter is setup for the correct injectors, no changes need to be made to the mass air setup since it is typically far more accurate than speed density setups. Unless your mass air sensor is dirty (the big culprit being oil from a reusable air filter), it shouldn't matter. It sounds like you are attempting to use the mass air with the stock 14lb fuel injectors?
If you actually did move to a mass air ecu, at a minimum you had to have installed the HO cam and 19lb fuel injectors. If either of these are missing, there's your problem.
As for my problem, most people wouldn't notice the issue as its only noticeable for about 30 seconds during normal drives. The nuisance is after going into a store, coming back out, and being in a rough open loop again for a minute or two. Warm open loop rough, cold open loop great and smooth, closed loop great and smooth.
I'll be doing a leakdown myself here soon since I don't have 100% faith in any of the shops I've had my car at - I get people telling me different things at different shops, all canceling each other out.
The parts as they are right now:
Block: .030 over on standard block. .0045 piston to bore clearance with file to fit rings (have to look up the ring gap - think it was like .022 and .026 or something). Clevite 77 bearings. Other usual machine work that came to $800.
Camshaft: 89 Mustang GT - 0 degrees advance/retard
Mass air sensor: 89 Mustang GT
ECU: E9P
Heads: GT40P 00 Explorer 5.0 with Trick Flow "stock replacement" springs, lapped valves as we couldn't verify the seats being cut and 93 Mustang Cobra/Crane Energizer 1.7 roller rockers. Milled for flatness.
Valvetrain: FMS Stock-type lifters, Stock 6.258" pushrods with no shims
Intake: 93 Mustang Cobra
Headers: FMS Stainless w/standard FelPro gaskets (copper leaked badly...)
Balancer: Pioneer SFI 50oz
Exhaust: Dual 2 1/2" with high flow catalytic converters, x-pipe, flowmaster 50 series lers
Transmission: '03 4R70w with Baumannator TCS
Computer codes 94,44,33. EGR code stayed after EGR valve replacement. Thermactor removed. 5in of Vacuum placed on EGR causes engine to stall at idle so it functions properly.
Cylinder balance test code 90 - PASS
Timing set to 10 degrees base
New TPS and sweep checked - 0.98v at idle, 4.68v WOT, 0.90-4.58v at the ECU
New MAP sensor open to atmosphere
New ECT and ACT sensors
Ignition Coil has around 2,000 miles
Distributor cap has around 3,000 miles
Distributor/TFI has around 100,000 miles
Spark Plugs have around 50 miles
Spark plug wires have around 800 miles
Mass air sensor has around 100,000 miles - cleaned
Idle air controller has around 225,000 miles - clean and tested to work correctly
Cloyes "True double roller" timing chain has around 800 miles
Felpro engine rebuild gasket kit - silicone lower intake gaskets at front/rear. RTV used around water ports on lower manifold gaskets and between it and cork. New upper/lower gasket as of last intake pull. Vacuum has standard fpr, vacuum tree, passenger fender and single press in fitting going to PCV valve. Charcoal canister hooked up to vacuum post on front of intake near throttle body runner. Old MAP sensor vacuum port is plugged off on the intake. All new silicone hoses with one standard vacuum hose going to charcoal canister and standard going to vacuum tree.
Entire build has ~800 miles now.
In order to do any modifications to you engine that are air related you have to convert from speed density to Mass Air to get the full potential of that part. Such as better Intake, Cold air, etc.. I plan on doing some modifications to my engine & that is why I converted to Mass Air. As for Seek you are correct in the fact that Mass air requires a mass air computer. A Mass Air conversion kit comes with a A9p computer depending on if you have auto or man. trans, Mass air sensor, mass air meter, wiring harness, & instructions to install everything. You don't necessarilly need to have a high performance cam to convert to mass air. As long as your sensor is calbrated correctly to your cars setting (which is what the Air adjuster does) your car will run fine with it's original stock motor & fuel injectors. Like I said before, the company I bought the Mass Air kit from said " If you have a High Performance motor or plan on making your stock motor into an HO, the Mass Air sensor does not automatically calibrate itself to your engine. If you don't understand or if what I'm saying makes no sense then go to http://www.mass-air.com & they will explain it to you.
Hey
I see you have replaced the ign module. Have you swapped the dist or is it the orginal??
Sounds to me like the Stator/Pick up coil in the dist is breaking down
when the car get warm.
I would replace it with FORD or Motorcraft parts. Have used most
aftermarket manufactors and they only work about 6 months before
the break down?
Had it happen to my 5.0 ranger,Black EFI 5.0 cougar and My turbo 351 Cougar.
PS Avoid MSD dist they have JUNK CHINA electronics
The coil was due to the original stock one having lower than ideal voltage a year ago. The distributor was swapped for the lower mileage mustang one as my stock one started "whining" - I didn't want it to seize up so I swapped it. I would think ignition if it wasn't for the fact that it clears up the second that it goes into closed loop and that the first motor that we put in ran excellent with the same parts other than the new heads, exhaust, and transmission (not to say something didn't "break" in the 6 months the parts were lying around in the garage).
I won't use aftermarket distributor electronics. If I start throwing more parts at it, the distributor electronics will be the first to get moved up to new status.
As long as there is good vacuum (non-aggressive cams) and no need for huge injectors, speed density works great. Once you need larger injectors, it loses some appeal though. Mass air isn't necessarily needed (it should help open loop...) with minor mods to the intake and heads. Oxygen sensors help speed density compensate a ton, and it doesn't run as overly rich as mass air to get a stock setup a little more power.
As for the mass air, this "air adjuster" I can see helping it work around incorrect fuel injector size but I don't see how you would manage to run a computer on a camshaft that has a completely different firing order. If anything, the engine would shake horribly and be igniting out the intake/exhaust due to improper camshaft timing. Moving spark plug wires around would lessen this but I don't understand how you could have an A9P working with the SO cam.
I only had the mass air parts for future tuning abilities and while they're known to run more rich, they're also known to give you better economy (aka efficiency which means power). I put them on when I had a bad open loop issue with speed density. With mass air the problem remained, but I gained a delayed throttle response...
About mass-air.com, they are who I got my harness from and I see their "adjuster" but again, that thing's just a bandaid. I see how it works and what its for but the whole "Changing Injector Sizes" thing throws out all credibility. With the correct mass air sensor, this isn't a problem. Anyways, for the price of that thing, I'm halfway to a second hand TwEECer R/T. I have the AEM wideband setup coming that will be installed the week after next.
Well your fuel pressure is in spec so I don'y know what's wrong off the top of my head :hick: The injectors *should* be big enough as my set up is very similar to yours (I have a different, non stock HO cam) that just eeks by on 19 lb injectors.
88cougar you really don't need/want to run mass air with stock 14lb injectors and the stock SO cam. You do know that your car does not have a factory HO motor right? It's different than a Mustang 5.0. Read this page: http://www.coolcats.net/tech/advanced/ho_transplant.html and this one: http://www.coolcats.net/tech/advanced/massair.html
Plenty of people have run larger injectors on SD motors with out issue using the stock EEC-IV electronics.
SD is much more dependent upon vacuum than mass air.
You performed a mass air conversion on an otherwise stock non-HO 5.0? I'm curious.....what injectors were/are you running with this very confused sounding setup?
Disproved by people on this very board and others such as http://www.50tech.com ...basic upgrades -- even cylinder head upgrades where people have run mass air after running SD and found the MAF switch slowed them down....
Mass Air is easier to work with AND it is more forgiving once you start becoming more aggresive with cam profiles and cylinder head flow as far as the stock Ford EEC-IV ECU's are concerned, but that doesn't mean you can't go with larger injectors with the SD ECU....
BSFC and volumetric efficiency as well as how much the ECU can compensate for those items with the readings it takes/is given from it's environment have a lot to do with proper injector sizing as well. A stock HO was rated at 225 Hp and was said to have around a .52 BSFC (a higher number is a sign of inefficiency and pwer lost to heat -- hence why your average upgraded H/C/I N/A 5.0 will have a LOWER BSFC constant). Throwing 30 pounders on a stock MAF equipped 5.0 even with a calibrated meter will be a waste. Even if it could meter it properly it would throw the injector duty cycle so low -- especially at cruising and low load conditions -- you'd potentially create other issues.
Seek, your other 2 codes are for the thermactor system....I'm guessing it's disappeared so to speak? You plugged the heads/lines?
I know my car is not an HO motor like a Mustang GT Duhh. I was told by a mechanic\ car restorer, that's done about everything that can be done to the engine on a 88 Cougar XR-7, that before I do any modifications to the engine, I need to convert it Mass Air. And It didn't say anywhere on the Mas air conversion kit instructions to install bigger fuel injectors & when I contacted Customer Service at mass-air.com they recommended the air adjuster & 19lb fuel injectors since my car is not an HO motor. I have the correct mas air sensor but it will not work correctly with a stock non HO motor. Like I said before, the Air Adjuster allows you to calibrate your mass air kit to your cars setting. Which I bought from them for $180 & so far the car runs fine since then & I can sell the Air Adjuster to someone else or use it on another Mass Air car. Since the conversion (which was over a year ago), I've decided to keep the engine mostly original & I still have all the parts i've tooken off. Thus to keep the car more valuable in the future. Instead of beefing up the current engine, I'm buying a Roller 5.0L motor out of a 90's mustang, put a 347 stroker kit, Edelbrock top end kit with a roller cam, aluminum heads, rockers, lifters, Air gap intake, & 750 cfm Carb. I've already got a posi locker & have a different transmission rebuilt to handle up to 500hp with a stall converter. And a few other little modifications to the suspension like brakes, springs, shocks, etc.. And instead of converting to 5 lug i'm buying 16" Chrome mustang wheels. Any other questions or things you think I'm doing wrong?
I understand that SD can be used with more but it's easier for most people to just use mass air than deal with tuning (not that I won't be messing with this ecu not too far out).
Anyways, they're gt40p heads - no thermactor holes and it isn't on there. EGR seems to work but I think I need to datalog it to verify that the computer is actually opening it up as "insufficient flow" shouldn't be happening. Once I find a secondhand TwEECer, I will be doing this along with a DataQ - I'm tired of wasting money having shops check out the car now when I could have all these cool new toys with that money. I just wish this project would stop being a project...so I can move on to doing more enjoyable things than working on a car every single weekend for over a year.
1. Don't ever listen to that person when it comes to EEC-IV tech again
2. Yes. You're keeping a closed mind. You also a little hostile for a new guy who we know nothing about...We get our fair share of people here who don't know what the fVck they're talking about....Your 12 posts here don't simply give enough info for some to determine whether or not you do or not. I understand you're trying to help, but at the same time you answered the questions in a way that gave rise to making me curious.....
And FWIW I'd go back to SD on your current setup.
Seek, have you done any WOT driving to see waht happens?
So it only runs rough while warm and in open loop, but fine while cold and in open loop?
Sorry, but I've been to about every mechanic in town & around trying to figure out why after i converted my car to mass air it started idling poorly, hesitated before it would go but runs fine while your driving it & on the Hwy. Then after 2 computers, and a new sensor I got back in touch with the company I bought the kit from & they told my to get the Air Adjuster which solved my problmes. And sorry for seeming hostile, but your one or two people telling me something that hundreds of other people told me something different. Not saying there right or your right but the car runs fine now. And the person who told me to convert to Mass Air builds high performance Ford's & restores cars & has built over 30 cars in his life time & sold most of them for over $100,000. Hey, maybe what I'm saying is wrong. I'm just telling you what I had to do that worked on my car. If you haven't had the problem I've had with my car or worked on a car with the problems I've had, then how can you tell me what i need to? I agree about going back to Speed Density Setup, but I've put to much money into getting the mass air kit right so i'm leaving it alone for now. In another 15-20 years when I go to restore this car back to it's original condition, & take out all the performance things like the new engine & transmssion. I'll convert it back to Speed Density, put the original wheels back on, & probably put the original radio back in. Sorry for the misunderstanding.
Yes...very hard to pinpoint the problem in such odd cirspoogestances. The only thought in my head this whole time is cold signal from ECT causing ecu to run extra rich - as it warms up, the ecu leans it out. Unmetered air getting in somewhere that is causing every last bit of my problems (warm open loop, along with excess fuel usage/economy all around). No where can a vacuum leak be found though, redone and new intake gaskets all around, disconnected vacuum lines, blocked off egr/iac, yet it still acts like it's receiving unmetered air. I don't think I can do much further testing without a smoke machine.
I did this at 700 miles on the motor - it runs great and accelerates scary quick (I was frustrated with my gps telling me things too late and having to keep turning around...it goes from 20mph to 60 in no time as long as I don't lose grip)
I'm sure the product does SOMETHING, it probably just does it in the wrong way (tuning rather than just changing voltages/resistances around). I see the product and won't touch it, I will leave it at that. If it works for you, that's great and I hope it continues to work well for you. It's no fun having a car that doesn't run right. This thing basically just makes the computer think it's getting more air than the mass air sensor is telling, so it gives you more fuel.
About people knowing what they're doing and saying - I haven't had the best experience with people who have "rebuilt" and "repainted" "20+ cars" as they usually know less than what I know, yet I took their word since they had more "experience". Most of these older people don't take the time to learn about fuel injection and try applying every carburetor trick to them - it doesn't work much of the time. This first shop I took it to told me to try putting my mass air stuff on to see how it worked, compared to the speed density. This didn't make much sense in my head besides the motor not knowing the amount of air actually coming in, so I tried it. Everything acted the same, but I also got poor throttle response afterwards. While I would have done this eventually, it didn't make sense to do it at this time - and it didn't help a bit. This guy's been around and working on Fords all his life. I don't trust the above advice one bit.
Anyways, good luck with restoring the car...even ever. NOS parts are becoming harder to find each day right now, it'll be even worse in the future. Then there's the whole thing about petroleum reserves and buttstuffog radio likely not being around at that point in time. I say do what you want to it and have fun. I'm just hoping for a "mustang electric motor"conversion" at some point as that would work in our cars and also give us the weight in the back that our rear wheel drive vehicles love. Gotta love 1,000ft lbs of torque.
Thanks for the info & good luck figuring out your problem to. I hope it never comes to electric cars only & no petroleum, especially with all the money & time we've put into our cars.
I just realized something.......
Considering my TFS setup runs 14" of vacuum @ 850 RPM in park, I would say your vacuum is a bit on the low side -- especially with the info provided. Have you tried checking it under load?
Here's an interesting animation for vacuum diagnostics:
http://sbftech.com/index.php/topic,3020.0.html
Click on each scenario. It's a very nice tutorial.
Has excessive lifter preload been ruled out of the equation at this time?
Yeah it idled poorly cause your mass air EEC is setup for 19lb injectors and the stock ones are 14lb, it was no doubt severely lean... As far as the guy building $100,000 show cars, few "shiny" guys have any real understanding of electronic fuel injection...
As others have mentioned a HO Mass Air setup will never work properly with the stock SO cam and/or the 14lb injectors... You really should convert it back to SD, but if you've got a serious hard on for the mass air, a EEC from a
'91 California Crown Vic or Grand Marquis should work... Those were the only SO 5.0 I know of that used mass air... You may need the matching MAF meter, I don't know if the HO was the same or not...
BTW if you're just going to convert it to HO and not install a hot cam, use a '87-'88 Stang SD EEC, it's been proved time and time again those were the quickest stock 5.0s ever produced... Yes I tried a Mass Air conv on a '86 Stang and lost .25 sec at the track(thought it felt soggy after the conversion), converted it back at the track(same evening) and it regained the lost time and felt like it's old self again... I never ran mass air on it again...
Are you sure it's actually in open loop warm??? The EEC will go to closed loop with hot o2 sensors and engine temp over 100*... With the heated 02 sensors that's almost immediately, on a warm restart.. Have you monitored o2 voltages when this happens???
As per FordFuelInjection.com
I still say your vacuum is low and you should look into why, but perhaps you do indeed have the same issue I did once I fixed my harness and got the o2's working. Perhaps they are reading from the wrong banks.
Refer to pins #29 & # 43 in the below diagram....
(http://i280.photobucket.com/albums/kk191/V8Demon/Car%20Tech/87-50Enginewiring.gif)
I will check this. When warm, if I shut the car off and start it back up, it always takes exactly 90 seconds before it smooths out. If it is in fact supposed to be happening sooner, something else is amiss. I think the DataQ would help a lot with monitoring these oxygen sensor voltages.
I will attempt to check the o2 sensors with a multimeter to see if they are correctly plugged in but is there an easier way? Perhaps just unplug one sensor and see what bank the codes say is disconnected? :hick:
I think if the above is true, then we may be onto something. I'm not sure it explains the vacuum though. My vacuum reading above is at like 650-700rpm's - it idles incredibly low right now. It gets a little more rough with the IAC disconnected. On cold start, it idles at 1100-1200 rpm's for 10-15 seconds before coming down to ~800, then slowly drops as it warms up. This is only going off stock gauge and going off the speeds the ECU shoots for at idle to figure out how "accurate" the gauge is.
The logic to go to closed loop is pretty complicated.
It's outlined on page 6-8 to 6-12 of the GUFB (http://"http://www.fordfuelinjection.com/files/GUFB.pdf") document.
Without re-taking the time to decipher all of the acronyms, I think it requires...
Part throttle
"Warm" O2 sensors
Thermactor not sending air to exhaust
"Warm" O2 sensors requires:
A certain number of O2 switches from lean/rich
Timed delay logic based on time from startup and time above ECT scalar input temperature
You have cold start, warm start, and hot start, which are all based on ECT temp at startup. You can look at the doc yourself to get the to the nitty gritty. Should be able to find the actual values from bins on eectuning.org.
You can turn on the ign switch for a minute or two prior to starting to see if it makes any difference in the time... This will pre-heat the sensors...
Now we're getting somewhere I think - this is all VERY useful information. I will do some of these checks. The performance shop watched the oxygen sensors and said they're switching back and forth around stoich properly but I'm not sure where they measured that from. Either way, I have a few things to check out as it sounds like me driving for an hour on the highway, pulling off, shutting it off, and starting the motor back up should go into closed loop (and in turn run smooth) almost instantly. This isn't the case as I have to wait 90 seconds at which point the rpm's go up momentarily, settle back down, and it runs smooth. Going off the tripminder, this switch from rough to smooth goes from 16mpg up to ~25mpg at the same speed if it switches while I'm driving. Back then I had popping through the intake at that point though - now I just have horrible hesitation where it used to pop. This pop apparently was from a bad seal at the IAC. During this hesitation, it takes a second or two before it stops and starts pulling.
OK here's the word straight from the horses mouth(Ronnie, just got off the phone with him)... Since it's been over four years since we worked on his, I was foggy...
He said his went through the same lean, rough running 90 sec open loop startup cycle, same as you've described... In the end the EEC did not fix it, BUT changing out the conical air filter for the original air box and filter did put the A/F ratio back near normal(actually a little rich)...
I'm using the stock airbox without silencer, with paper filter... *sigh*
Check those HEGO wires....
Jeremy is right here - in fact there is a hot start timer - OPCLT3 it's called, that is set to 60 seconds in A9L. Here is the description:
I've never seen my car go closed loop before 90 seconds either, so I wouldn't be too worried about that. I would look into a vacuum leak - you should have closer to 18 in Hg at idle with a stock cam. Have you checked the PCV? I didn't see you mention it above. Do you still have the hose that goes from the TB to the valve cover? Just trying to figure out where you might be drawing unmetered air.
PCV has newish valve, screen, and a custom grommet that grabs it tighter than the stock ones that always get loose after 3 months (in my experience). Hose is new and runs from the valve straight to the single fitting on the back of the intake. The hose is very tight.
The line from the filler neck to the throttle body is on there but still the stock line - it seems to fit snug but is easier to pull off than, say, the hose on the PCV(the entire valve comes out when I try disconnecting that thing). I'll try to get a couple pictures of the engine bay tomorrow. I've plugged the charcoal canister, fpr, vacuum tree, other smog(or whatever, goes to passenger side firewall) with no changes. The "MAP" port is capped off. I've disconnected the egr line just to make sure it wasn't opening up when it shouldn't.
Someone way back when(old Easyboard), had a cracked intake that was driving them crazy...
How do people manage to crack them? Other than the obvious - a nasty wreck. The intake is the same as in the past motor that ran fine except now it has fresh powerdercoat - 400 degrees cooking for a few minutes to get the moisture out, then more for the powdercoat to melt.
Not a clue on how it cracked, but it wasn't obvious...
BTW, I've ran my GT40 intake with no upper to lower gasket and honestly couldn't tell much difference... But then my engine only idles 12-13" anyway...
I've got a tweecer r/t coming - just need to find the usb/8 port dataq unit that isn't out of stock. Not that I think this will help much, I've been trying to get one for awhile. I was 24 hours away from getting one for $275 on eBay but a day early the Microsoft cashback disappeared from 30% :(
I will be out of town next week so I won't be posting in this thread during that time. I will be trying some of these suggestions on the car here in a bit.
Are yo sure the lower intake is not leaking? I was trying to follow this for a few days but got side tracked. To me it could be that.
Perhaps baking it distorted it since it wasn't constrained as it would be when mounted on the engine. I know I had a stock lower shaved (to match shaved heads) and the machinist was surprised at how much the mating surfaces were distorted.
Okay, I'm back. After having taken the car to Canada and back, I've found some interesting things. First, the big news. I found that Averaging 63-65mph, I obtained 31.9mpg with the engine is it is over 150 miles that start/end at very close elevation. At 75 I started getting 29.5-30mpg. 80mph I'm getting 28.5mpg. I'm not sure if it was always like this or if my last couple tests weren't complete, but I've had a ton of travel time to find these values as being valid. I was getting 28mpg solid until it seemed out of nowhere I started getting 30mpg on flat terrain. Perhaps the engine's breaking in more now that it's had a good amount of time to run with the oil thinned out, I don't know, but the economy figures I'm seeing are promising. All the above figured are with NO cruise control, just accelerating, then coasting, over and over again. The vacuum from the coasting seems to overcome what losses are taken upon light acceleration - possibly being why I'm seeing the above economy that much higher than when I was using the cruise control. Putting an electric fan back in should give me the same boost I saw on the stock engine also ;)
Anyways, with the above information, I'm looking to just smooth out the rough open loop idle and go from there. I'll see what everything shows once I get the tweecer and wideband in there. If that's gone, I can deal with the car for the most part and check out the parts whenever I yank them off again.
I also need to look into why my gas tank doesn't seem to vent properly at most pumps. It takes 3-4 fillups to get the fillup amounts accurate to the values the tripminder is showing as burned.
Clogged/pinched vacuum to the canister purge system.
?????????????
Fuel usage reading in the tripminder.
The vacuum line going to the canister is new - the line from the fuel tank to the canister I haven't checked recently but the car's had this problem for as long as I've had it. Slight downhill pumps always let me fill it to the top though...otherwise I only get 3/4 tank.
UPDATE!
Got the TwEECer installed but haven't wired up the DataQ/wideband yet. Anyways, I'm still trying to figure out the logs but the rough "open loop" problem is actually right after it switches to closed loop, and through 30 seconds or so. During this time, the timing is bouncing up and down. I also turned on all drivers/passenger side separate monitoring and found the injector pulse width to be double (I assume one bank?) on one side than the other. This all clears up when the HEGO's both drop for a couple seconds, then come back up and the injector banks both start reading the same (or close to one another).
Now I completely forgot about trying to switch the oxygen sensor harnesses around until now so would this cause the above symptoms? I figure I'll give this a try tomorrow as it's about dark and the engine's hot.
I was looking through the logs and sure enough, this appears to be the problem - it expecting richening results but seeing them on the wrong sensor.
Of course, the grounding wires for the oxygen sensors are keeping the harness from reading the 18" oxygen sensors...*sigh*
I'll have to try swapping them tomorrow when I have some light.
Anyone have any information on what the EEC is doing during this time other than some type of calibration?
One thing I missed was apparently when it cleared up on my datalogging earlier, the car went back out of closed loop?! You can check out the screen at the link below. I fast forwarded through a couple parts of repetitive logging to get the file smaller but the transitions are all there.
From what I'm gathering, HEGO 2 is reading lean while it should be getting excess fuel. Also, I have yet to see the car hold (even while driving it) .4-.5v except with large fluctuations - should it not be around 4.3 for 14.7 most of the time?
LINK! You only need the Macromedia Flash/Shockware player installed to view:
http://home.comcast.net/~seekproj/1.htm
I couln't tell you what the voltages would/should be without digging around, but I had a feeling your harness was reversed.
Glad you found out ;)
I went through this same thing and all the while I had NO codes even in KOER mode....
In a nutshell :)
Cool Video BTW!
Yeah, the biggest annoyance is only being able to log 16 pieces of data so with logging driver/passenger side pairs, I had to turn off a lot of the other sensors.
Swapped the wires and sure enough, the oxygen sensors switch properly now. This last trip when I noticed a sudden change in economy (after pulling off the highway to fillup), it must have been it successfully going into closed loop somehow after getting back on the road. Now I should be seeing solid 30+mpg instead of upper 20's I normally see.
The rough engine on warm startup is gone.
I've been having very similar problems with a twist. I get the horrid sluggish condition and lean backfire through the intake but no codes. The car acts as you had described your car. I get an odd idle hunt that will stall the engine as it revs down and up so hard. I'll have to look into this injector harness thing.
Well this was a quick fix. My Hego harness was installed correctly but while checking this I found the orange Hego ground wire to be loose. I must have forgotten to tighten it when I installed the motor in July, I was in a hurry getting the car ready for Cat Jam at the last minute. After cleaning the ground and the head surfaces and reinstalling I went for a drive. The car drives nearly perfect now. I can tell the car is going into closed loop and not having any issues now. I do still have a 100rpm idle flutter when I come to a stop but it only does it twice, no more hunting until it kills itself. I believe this is happening as a result to my raising the base idle up on the t/b to compensate for the hunting. I'll lower it back down and see what happens.
Thanks Paul and Seek, without a problem relation to Oxygen sensors I wouldn't have found this without mucho digging.
It's amazing how something so simple could cause these headaches. At least mine would clear up as it'd drop back into open loop after the o2 sensors failed to respond as the ecu was expecting...
I have yet to have any more problems - it runs great and should do even better once I tweak some things a bit. I get like a single hunt when it goes into closed loop when I'm in park/neutral (which the datalogging shows to be when the sensors both go lean for a second), but doesn't happen if it goes into closed in drive. It's only like 50 rpm's either direction - hardly noticeable. I have to get a new fuel pump in here though as I see 70% duty cycles on my 19lb injectors at 4,000 rpm's - somewhere around the range my stock fuelpump should be cutting out also. I have one coming, along with 24lb injectors/75mm Pro-M mass air sensor which should keep me out of lean up to ~5200 rpm's where I have to make the transmission upshift due to its stock stall converter. Sometime this spring/summer I'll try installing the Keith Craft CNC'd afr165's to get some more timing thrown in. It will be interesting to see what the HO cam will do in terms of a wide power/efficiency band. Gotta keep that economy up as gas will be $4+ a gallon again before we know it.
While I would drive down the road and the car would start to stumble if I started to give it gas it would go back into open loop and run fine again.. and repeat for the entire drive.
I'm running a very similar combo to you. GT40 heads, stock HO cam, exploerer intake.. I am running a 190lph pump. Still on SD though.
I've been averaging 25-6 MPG so hopefully I can do better with it running right.
My biggest problem is the stock cast iron manifold and the stock split XR7 exhaust.. sans cats.
I think once it fails to go into closed, it stays that way - it doesn't try again until you cut the ignition and restart the vehicle. I had similar economy to that when it was stuck in open loop (best of around 28mpg). My gt40 headed motor (block ended up being cracked) got me a best of 30.5mpg I believe, when I was using the stock exhaust and aod when using speed density. I'm really thinking I may actually gain highway economy, or be about equal if my rearend had 3.08's.
I'll be looking to put an electric fan back in there soon to get the boost I saw on the SO engine. I need to get a new temperature sensor though as mine went missing in the garage. It would be nice to lose the load of the mechanical fan once again. I got around 33mpg at 75/35mpg at 65 with the stock motor with the electric fan which gave me ~1.5mpg boost (some of that may have been different gas blends, it was so many years ago now) on the highway. If I'm lucky and have similar results, I should be able to see a best of 34mpg after some tuning although I'd love to be able to se 35 out of the car again on a 150+ mile trip.
Honestly, I think I need to focus on suspension soon though as my front end is making some interesting noises. Sounds/feels like my springs are shot, along with the struts. The control arms/ball joints are the newest things and they're probably 5 years old now. I'm hoping to do this with the 8.8" rearend install with TC brakes on the front/rear at the same time as I'll already be working in the vicinity.