Remember a while back? The rough idle, choppy performance? Well, I swapped many parts and a new coil did wonders. Now, it's running good (needs a clutch), but at times, it'll start to have an erratic idle after I drive for a bit, but if I turn the car off, and turn it right back on, it's gone....at low speed or stop, the tach bounces and the idle is py. But as I stated, shut it off and restart,...good to go for a while. Ideas?
I think I may have the cure...
You could sell 'er to me...then the issue wouldn't be a b other to you anymore ;)
Ok, more seriously, did you ever try a different EEC? I can't remember if you said you had tried that or not..
Not yet. And no, I'll never sell that car. I'd part it out first.
Besides, I still haven't seen you finish YOUR Bird yet. LOL.
IAC valve could be sticking
WHO did i here you say the COIL WAS BAD. Heavens to Betsy. Wonder who said that. D'OH!!
Rough Idle means only a few things. A vacuum leak or a valve not seating correctly. Or a lean mixture. Other things being equal a bad injector or the ECM. But why would shutting it down clear the issue if it was an ECM. WOW well you have to do a balance test to isolate the issue. Also one of the sensors may be out of range. Check them statically. Also when the idle gets rough does performance change?? You said it is surging. So is the TPS ok and adjusted correctly??
I have no idea why shutting it down helps, but it does. I shut it off, and immediately turn it back on.....good to go. I'll do a balance test on my days off this week (I work tomorrow and Monday, then off for three days). I have a couple of extra IAC's on hand that I can try.
If it was a vacuum leak, it would seem that it would be an issue all the time, not only sometimes, then gone when I re-start the car.
I belive I said check the coil
I swapped the coil to a new MSD piece. It made a huge difference. Now, it's doing a little of that stuff again. When I restart the car, I don't give it a cool down period at all, just off, then back on.
Try swapping the computer
ECM ?????????? Possibly it makes sense because of the shut down issue. I am willing to bet this car has 2 issues. The first issue was most likely not fixed 100%.
Coil I thought someone else said that early on. WHEEEEEEEEEEEE!!!
I threw a vacuum leak in because at a restart the ECM rich-ens up till it levels off. This could mask a vacuum leak. Just something to check. How a bout the PCV VALVE. Just picking at straws. I saw one once that did not seat correctly and caused a condition like this once. By the way this is your new engine correct??
If you have a spare ECM just POP it in and that will eliminate that part. If it works you are golden if not it was worth a try. May be the ecm they can do weird things like that.
TFI module
try it
unplug the IAC and take it for a short trip. See if it changes anything. I had to change the one on my 92 dakota because it would open up and run at high idle for warm up, then never close and run like . Might be something to look at?
I have the new TFI in the garage. I'll swap it on. I'll re-re-re-re check the vacuum lines, and PCV and also the IAC again.
TFI is a good idea. But i thought you already replaced it ????
Just picking your brain Vinnie, does it do it at all running temps? or only hot/cold? that might help pinpoint the issue
This is how i modify the IAC for proper operation. First break it down then do some fancy grinding on the pins . This will allow the IAC to only allow a certain amount of bypassed air to enter the engine. And in turn will not allow the engine to exceed the cold RPM you set it at. Just another TIP!!
(http://i740.photobucket.com/albums/xx46/proguns/001-58.jpg)
This happens at any temperature.
Tom elaborate on that a bit more. Also about the grinding.
As far the TFI, no, I bought one, but didn't replace it yet since the coil APPEARED to have fixed the issue.
Swap the TFI first, since you have one there, and it's about a 3 minute job, IF you have the teeny little socket. Oreilly carries them i do believe.
If it ain't the TFI, I can send you my Mustang's EEC (89, mass air, AOD car) but, I will need it back pretty soon since I will need it for the other Mustang, but that's a whole other project for a little later on..
Thanks Beau. I may take you up on that.
yeah, I have the hand held socket for it. I also noticed something, my wires to the coil in the plug sem loose...I'm swapping the plug tomorrow as well.
I had a similar issue a few years back. Except mine wouldn't run good. Turning the the key on and off and it would clear up. I changed the Ignition switch and wired in the speed sensor to the ecu. You have an 88 I don't think you have to do the latter part. One of them cured my problem.
I think Vinny has a new switch i THINK??? But if it is not slaved out that is a given. Ignition switch slaving is a MUST!!! He can check it out by just feeling it and see if it is HOT!!! Or making some funky smells. WHEEE!!!!
No loose wires Vinny that can be an issue !!!!
TIP !!!!!!!!!
Over the years i have been changing the TFI modules and substituting ALLEN HEAD SCREWS for the stock ones. A quick drive to the hardware store and thirty five cents does it nicely !!! Also a 1/4 drive deep Snap On socket does the trick nicely. Or just buy the proper tool. Just some options!!!
When i substitute the screws i put a DAB of red paint on the module to let me know they are ALLEN HEADS!!!
I'll try that as well. I have an extra ignition switch in the tool box drawer.
I have the proper TFI removal tool. That's not an issue as far as swapping it.
Make sure you use good dielectric grease on the new TFI. Some guys say heat sink compound, some say the grease...I say grease as well.
My new Ford TFI came with it.
Dont use dialectic grease use heat transfer grease only!!!!!
I had planned on using the grease that Ford included with the TFI.
Since you have the TFI to put in, swap it and make sure that's all okay. Get a "canned air" can from Staples or wherever, for dusting out a computer, and blow that on the TFI when the issue comes up (don't hold the can upside down so that the propellant comes out icy cold and makes that neat-looking cryogenic mist in the air...don't freeze-shock your TFI when it's red hot!). See if cooling it down helps. My guess is not. Especially if this is a repeatable "fix" where shutting down and restarting takes care of it. It's an open-loop/closed-loop issue, I would argue. I *believe* the ECM reverts to open-loop mode for a given period of time, whether that's 10 seconds, 20 seconds, 2 minutes. It certainly starts out in open-loop when the car is started dead cold. Which would suggest an oxygen sensor issue, whether it is the sensor(s) themselves or connections. Check the O2 harness ground as well as each sensor's own grounds. This is where it would help to know someone with a scan tool that can read the parameters in real time, to see if the O2's are flip-flopping 1-0-1-0....like they should.
I need to re-read up on the EEC-IV strategy because I don't remember, but I there is a method to the madness and the reason you see that temporary improvement is the same reason my Crown Vic would do the same thing on a hot summer day back two years ago when I first installed the ill-purchased aftermarket-cammed bad rod bearing motor it currently has. I think getting a 160 degree thermostat and massive 3-core radiator from RockAuto helped a lot. It idles with only 16" of vacuum because of that cam and thus runs pig rich. Last summer it was okay however, I think it runs just cool enough that the A/F ratio it has to deal with doesn't push it over the edge and cause it to start stumbling. It would frequently backfire lightly through the intake when opening the throttle quickly as well.
Mine has a few instances of backfiring through the throttle. Timing was checked over and over, and it's fine.
The only sensor I haven't changed is the ACT sensor.
Vinny the ACT has very little to do with strategies. On obd 1 Ford ECM'S. The O2 does have a lot to do with running parameters. But allowing an engine especially a computer controlled one to operate to COOL is NG. The ecm needs CTS to properly adjust the AF RATIO. With that the ECM does start out in OPEN loop after a shut down. But with a worm engine and a HAGLO this lasts for a very short time. Restart Parameters are extreamly fast with HAGLO O2 Sensors!!
Just get it over with and buy a moates quarterhorse :p. A lot of issues like this show up quickly in datalogs when you dump data from 50 different sensors and data sources at 5ms intervals. It's spendy to get started, but I found troubleshooting got very easy after getting setup. You can capture the problem once, note the time that it occurred, then just sit inside a warm home in front of the PC and figure it out. Sure it may only point you in the right direction at times rather than tell you the problem, but it removes the need to bang your head against the wall as you swap parts around. I'd assume this issue would appear and you'd find some sensor that is reading different while all the others are reading similar in similar conditions. This leads to the cause and solution.
Swapping parts can get expensive over the years. It's needed though if the EEC is commanding one thing and what's actually occurring is something else (bad parts).
How's the ambient temp? Does it do it in both the morning and evening? Before I parked my car I was getting rich in the morning and lean in the afternoon, giving me an AFR swing of one entire point. At the stock command 11.7:1 after warmup, this was fine as it would be rich in the morning and 12.7:1 in the afternoon. As I adjusted to 12.5:1, I saw the problem as it would go 13.5:1 in the afternoon, and stumble. These were WOT issues, but I wouldn't be surprised to see ambient conditions making your problem come and go either. The EEC, even with good parts, can adapt pretty poorly in ways of street-ability.
I'm with everyone else at this point with what we know. The uneven idle is likely the IAC being commanded to open and close by the EEC from another sensor's input. The cause could be anything under the hood.
Well any ECM that bases it's AF Ratio on an o2 sensor sucks. Wide band is the only way to TUNE. With that a stand alone is the trick. BUT it is expensive. And then you can use COP and or CLP for spark and that is how that works out. Nothing beats a stand alone. I agree 100% But Fords are known for IAC hunting. There is several things that cause it and most likely the TPS comes to mind. Other than that the ECM can have a GLITCH as well. Basically the Ford EEC obd 1 system is not the best by any means.
hit it with a timming light with spout in and rev the motor and see if its advancing the timing like it should
Just another thing to check
Agreed. I do like how easily the aftermarket chips can get into the ODB1 computers though. Ford's first attempt at EFI was pretty good imo. ODB2 (and ALL the versions that are built on top of it) provides a ton more built in diagnostics. Wideband helps a ton, but the systems can also tell you quite a bit from the narrow band sensors. It they fail to switch at times of stumbling, then it isn't running at stoich and slightly rich won't cause a rough ride like slightly lean.
The EEC is VERY picky about certain things, as I found out about it not liking functions that produce anything but a curve. Engine flood at tip in comes to mind. That was an odd one to figure out. I have NO idea why the EEC does calculations in the way that it does. It can't interpolate...
I'm still working on it.
So...are you comparing open vs. closed loop here? Fordfuelinjection.com (formerly that, now oldfuelinjection.com after Ford's lawyers went after 'em) actually placed the ACT very high in the hierarchy of inputs for EEC-IV. At least upon startup anyhow. My black '88 XR7 with a Trick Flow setup has its original ACT in the intake, but the previous owner actually *induced* a problem by purchasing a second ACT and plugging the harness into that one instead, and cutting a hole in the air filter box, stuffing the new ACT there. I undid the "mod" and this partly cured rough running under a number of conditions. The rest of the fix included a new PIP and O2 sensors.
I definitely feel that a lot of these issues get caused by multiple part failures. My red car (GT40 heads, ported TMoss intake, 19lb/hr injectors, 65mm Explorer TB, Mustang 5-speed DA1 ECM, stock H.O. camshaft) runs and idles great without an IAC, throttle set manually, and the EGR valve defeated by tape stuffed inside the vac line. My friend's 1990 Vette by comparison, actually throws a check engine light when even one thing is unplugged. Different MFR's designs obviously, but it always him off that I get away with this and that disabled. My argument is however, definitely in favor of EEC-IV, though not necessarily. A halfway decent FI system clearly is designed to have enough sensing of conditions to still keep the car going if one or (maybe) two sensors fails.
EGR is operational allowing more timing with less fear of detonation. EGR also lowers the amount of oxygen in the mixture by about 15%; this means we don't need as much fuel. Timing can be advanced to increase engine temperature and counteract EGR influence upon igniting combustion gasses. Timing is used to control engine temps, hotter engines burn fuel more completely. The EGR is crucial for exact ECM operation. As for ACT it plays a part in the mixture as it adds slightly more fuel as the incoming air cools down. normally at WOT. Therefore it is limited at best. GM OBD1 is far superior with it's data stream parameters and monitoring ability. The old adage of a ball bearing in the EGR vacuum line id something to be desired. As the ECM is designed around it and it will increase performance drastically. Thanks Tom
Note The IAT has more control in a speed density setup than a MAF setup. Just wanted to correct that.
The KOER self test will check this. For two minutes after the last code is outputted the timing should equal base timing plus 20°
I've got to put brakes on a car at 9 this morning, then it's my time. I'll see what I can get done. KOER test, and balance test if time allows..
Correct the Scan tool performs this automatically .
But i guess some guys want to see it with a light.
Now if i can only find my timing LIGHT. Most likely under a foot of dust. Just kidding i do have to use it on the midnighter. By the way advancing timing more than 2* in most cases messes up the ECM. It allows for injector operation in some cases to early. As the ECM relies on cylinder location by the DIZZY. Just a thought!!
Tom, is it that way with all of Ford's 2.3's, (say, a '90 Mustang 2.3?) or is that applicable to the '87-8 TC only?
Reason I ask, I have a '90 Mustang, that I could never get to run right, and I wondered if the dist. was off. Actually, I know it has to be, because I timed that beeyotch at least 50 times, but never messed with the distributor.
Sorry to hijack Vinnie...I'll get this back on topic now :)
Hey Vinnie, Did you check for codes? I didn't see where that was mentioned.
Hey Kitz....check this page....it has my codes.
http://www.foxtbirdcougarforums.com/showthread.php?35094-Still-having-an-issue...UPDATE.../page3
As far as i know it does. The OTC does a complete advance scan and actually advances and retards the timing in sequence. As far as static timing goes remember the ECM used the DIZZY for TDC location. Another words it looks at the PIP to determine injector pulse or discharge timing. So if to far advanced and or retarded the fuel tables are delayed or advanced with static. Been messing with this on the MIDNIGHTER. It is extremely sensitive and makes a big difference.
I swapped in the new Motorcraft TFI today......had to wait around for the AT&T guy to show, so, I'll test the car tomorrow.
That explains why when I turned the dist one way, I could get it to run decent at lower rpm, and bad at higher rpm, and vice versa.
Gimme a 302 any day..
/end thread hijack lol
You should also check to see if you have a cracked spark plug
How to exactly check for that issue with this type of problem is kind of beyond me
The easiest way is to use a timing like to see if the light is stroking Steady or if it jumps around
I still have the very same issue you're describing and I've not narrowed it down yet
Also with the TF I removed probe the black wire connector of the stator with your ohmmeter and place the other meter lead on the distributor chassis and check for 0 ohmes
The black wire of the stater will be soldered to the stater mounting bracket inside the distributor and aftermarket does a poor job of this important connection
Add a temp wire from the tfi harness black wire to dizzy chassis and see if the issue improves
I'm re-re-pulling plugs and swapping the plug wires probably Sunday. I work the rest of the week, 12 hour shifts, so no car time this week.
I would think, a broken plug would be an issue all the time, not just sometimes to where it happens, then restart the car and it isn't there for a while. I have no idea. After plugs and wires, probably taking it to the shop.
Offer still stands to lend you my Stang's EEC...text me, I can get it out and on the way to you asap.
Do you have an an A9P or an A9L in there now?
I have an A9P in there right now (a reman unit). If you want to send it to me, I'll return it. Thanks a lot. I gotta get your text number again.
Once the kiddos are in bed, I'll pull the EEC and get a pic of the code to make sure it's what will work with your setup (though I'm sure it's an A9P, '89 Stang, AOD trans.)
I'll shoot ya a text in a few so you'll have my numerals again ;)
I need to gather funds and buy one.
You and i have had the same issue that occured around the same time.
i am still sucessful in making it go away and come back like i described on your other thread but........... i did initially throw a TPS at it becaue that is what it "felt" like. it happens at a consistent low speed while possibly in 3rd or od, and while i am lightly on the gas pedal.
I pulled my codes and focused on the EVP and the solenoid that controls vac to the egr,, you dont have an egr, i do.
for what its worth, i have no friggin clue what this is but i want it gone badly. When the wifes Ghia is out of the stall, i will work on this some more.
sorry no help here, hope you figure it out. the codes i get really dont tell me where "I THINK" i should go but ikeep believing my eec. I can throw spare good parts at it till the issue is gone but like you its an issue that only crops up after the engine is warm.
question for you though and im interested in your response....
~have you noticed that when you first start the car and lets say you drive a short distance somewhere , turn off the car, then in short order you start up again and during your second time in the car , does it seem to show up then?
im seeng this on my end. Initially even after warm up it rarely shows up, it will always show up the second time i get in and start up.
Yes, that happens at times. Initially, drives great, after I stop and start it can happen, but, it also can happen without stopping the car. Not long after I drive it a short distance.