The 88sport 5.0 aod, according to my son mason may be getting too much air at wot.
he says that if he floors it, the car seems a little "flat" or lacks response like it should but...... if he backs off the gas pedal about a 1/4'' or so, it pulls much more than at WOT.
dual 2 or 2 1/2'' exhaust with stock headers,
stock fuel pump
explorer upper / lower
larger tb, i think its 70 or 75mm, cant remember but its not stock
stock heads
so im thinking the fuel delivery is not there to match the air flow.
lets see how much i know.........
tps is assisting in signaling EEC to PWM the injectors but the stock injectors are not meeting stoich so he is for general conversations sake, he is running a little lean at wot.
~an adjustable fpr may cure this by allowing a tad bit more fuel in from the rail = inexpensive upgrade
~a little higher velocity fuel pump may cure this as well= little more expensive, offers up the opportunity to do some preventative maint when the tank is dropped.
~swap in an upgrade to injectors which is easy as long as the SO EEC wont reject them
~adjust the trottle cable so that he never feels this again thus reducing his max wot performance and possibly saving his ass:hick:~! too easy
does this symptom sound familiar to those of you who were where mason is today?
thoughts?
Have you checked the fuel filter? You a fuel pressure gauge that you can install on the schrader valve and have inside the car to see if the FP is dropping at WOT. I would start here before I did anything else.
Darren
I dont think a higher volume fuel pump will do anything additional without a adjustable FPR to raise the pressure. I dont think you should add bigger injectors without a tune to input the change. Could swap back the stock TB and see if the symptom goes away.
Is the throttle position sensor in range at WOT?
tps is good at wot with an buttstuffog meter.
good points on check the fuel presure,, i feel dumb now but its ok.
when he comes home again ill do that.
i need a fuel pressure extention hose to put it up on the windshield while driving to see whats happening under a load.
i meant to get one of these a while ago.... another excuse to get a tool,, i love it.
I never had issues when I had a 70mm tb with stock injectors. The fuel filter is a great place to start since it only costs $5.
Stoich refers to the 14.7:1 ratio at cruse or other light throttle condition... For max power at WOT ratio needs to be around 12.5 for a NA application and around 11.5 when boosted... The extra fuel when boosted is mainly to keep mixture cool to lesson the chance of detonation... At 10PSI my SC Marauder was at 11:1 which is considered a safe tune for those engines...
As suggested if F/P is a steady 39psi at WOT the fuel is at the rail, problem then would be under size injector for your mods...
say part 2 of your last sentence again,,,
are you saying if i find all is well with fuel delivery, that the injectors are undersized for my minor mods?
Basically that's likely the problem... I assume you still have the stock inj and ECM???
correct,
the reason i wanted a reword is your thinking what i was thinking, needed confirmation
Ill measure the fuel presure first though and swap filters cause i have one,, but Ill take your word for it if the results stay the same.
Mason and i discussed this and i told himi wasnt exactly sure if there is a recommended fuel injector for an SO non-mass, non-ho application where all we did was just increase the amount of air flow.
in theory, i suppose the heads are a bottle neck but those get replaced with GT irons or something better later this summer.
if i can rememdy the issue with the next step up injector and not risk "too much" fuel, keeping the SO eec, that would be nice to know.
The stock 14 lb/hr units should support in the range of 200 fwhp if everything is in good working order. If you need to bump it up to 19 lb/hr units then try and find a Mark VII ECU as they are a direct plug in on an SO motor and will support the 19 lb/hr injectors. At least that is what I have read as I have never done it myself. Me personally I would just start gathering up the parts for an HO swap and be done with it but that costs $$$.
Darren
The speed density ecu doesn't know what to do with all the extra air...its that simple. You have lots of options, but none of them ideal...like the mark 7 ecu will control the 19lb injectors. But without the better heads and cam you will probably be rich, for the lack of air flow. You can chip it...$$
I guess I would ask the kid if he is going farther with the mods on the car??? If no, you probably could get a adjustable fuel pressure regulator and gauge....bump it up until the flat spot goes away. Not to high...like no higher than 45psi. He may also need a better fuel pump...not sure on this???!!!
How fa$t doe$ he want to go?
Travis
I dunno about the Mark VII EEC not knowing what to do with the "lack of air" being that speed density still uses O2 sensors and the tables should be able to compensate for that. The Mark VII's were not all that great at air flow them selves so I think it would be a better situation than what he is in now if in fact larger injectors are needed.
I do agree that the fuel pump needs to be upgraded and an adjustable fuel pressure regulator needs to be installed but again it would only be if the fuel pressure is falling off at WOT.
Darren
By default ford engineers gave there engines lots of fuel...WOT really rich.
The computer has no knowledge of knock...so father Ford made them rich at WOT.
So the average user can add a cone and exhaust to a speed density 5.0HO and it makes more power.
The 88-92 Lincoln mark 7 used speed density, because Ford didn't think anybody was going mod it.
That user is just leaning out the fuel curve....of course that car picks up...a good thing.
But with the SO setup...father Ford...didnt leave much room for mods on that setup.
Travis
If you plan on making changes to the air/fuel ratio, you should get a wideband monitor. That way you won't be taking stabs in the dark. Its an excellent tuning aid.
I think your bottleneck is the e6 heads with the explorer intakes and 65mm+ size throttle body. And like whats been said, I don't think the SO computer and injectors can support your air:fuel ratio.
Considering that plenty of people have supercharged cars with stock EEC-IV style SD computers and they do indeed run faster, I'll say that it can figure it out -- to a point......
At what speed is this occurring? From a stop? Or are we talking at highway speeds when the vehicle is moving?
This.
And if you install the Mark 7 EEC and injectors, you'll get the best bang if you also go to an HO cam. Of course, if you're going to get that far into it, may as well spring for GT40 heads too...
I know that doesn't have diddly to do with what you originally posted...but I feel that the issue is, as Darren and Paul and Tom mentioned, either a slight lean issue at WOT, but if you cure that issue, the better heads and cam are the next step.
I've got a Mark 7 eec and some 19#, indeed, I think I could even scare up an HO cam, if you guys are wanting to go that route.
Im sure dumn luck had something to do with it...the O2 sensors can help competsate...but not much...I would assume the HO 5.0 would have more flexiblity than the SO 5.0. The OP was discussing that...his SO wasnt running correctly at WOT...which is what I was commenting about.
The SD HO and the SD SO 5.0 just dont know what the air flow is(common to all speed density setups)...that is why MAF was such a boone to the 5.0 in 1989. Some people have had some luck by really uping the fuel pressure. Installing bigger injectors, blah, blah.
So if a buddy of a buddy has done a supercharged setup...good for him. But he would be the exception not the rule. So many people from 1986-1988 to the maf upgrade on the 5.0HO.
Travis
paul,
at moving moving or from a stop, if you matt the pedal it is sluggish,
back off the pedal just a half inch or so and it comes a live.
other than dual exahust, this car moves so much quicker than my 20th yet we both have the same rear gear tag.. trying to contact the prev owner to fnd out what he did.
even with the stock intake(s) & TB, the difference was night and day.
here is the link to my buying from "privateer", nice guy.
maybe someone like you can figure out or read betweent the lines at tell me why his car is twice the coug.. i swear the rear gear is upgraged but yet a "made in italy" 373 rear gear came with the car new in the box and axle bearing kit.
transmission on my car and his are identical,,, never saw a hint in any of priateers threads he swapped in better valve bodies.
i was hoping to stumble across his mentioning a stall converter but found nothing.
im up for that, need to score heads..........304 772 3411, scott
sounds like no choice but to swap in a maf as well.??
i sure would like to not modify the engine harness for the sake of year correct wiring though.
perhaps heads only ??
he (my son) doesnt really need the car to start drinking too much gas
would like to remedy the issue without going H0 but its not that big of a deal i suppose. He's not all that interested in keeping it correct to the year like i am with the 20th.
When you go WOT and the car falls on its face can you tell if it is running rich? I would think that if at WOT and it was lean you would definitely be getting some detonation. Pull the plugs and see what they look like. If you are white or light grey with some black specs on them then you are detonating and running lean. The plugs will look like this:
http://www.carcraft.com/howto/116_0703_spark_plug_guide/photo_07.html#
If they are black or dark grey then you are running too rich. Its old school but it applies to injected cars as well as carb'd cars. If you are running rich it may be that you have some lazy injectors and when the EEC goes to 100% duty on the injector pulse they are not spraying correctly and flooding the motor. I think it has been pointed out that the SD and MAF cars ignore the O2's when in WOT.
Another thing to check is if the EEC is advancing the timing. Put a timing light on it and rev the motor to see if that is actually happening.
Darren
To go to an HO swap, you can stay speed density, not one wire would need to be changed under the hood, except for moving some plug wires around on the distributor.
The rest would be swapping heads, cam, and intake. The Mark VII eec is still SD, and is truly plug and play. Also, a Mustang DA1 is identical.
I have some E7 heads, 19 pound injectors, and the upper/lower intake. Possibly a cam, and for sure the Mark 7 eec.
All or any part of it...PM me if you guys are interested, and we'll get something worked out :)
1000% well said and that is how it is dun. You can't guess. Best way is on a DYNE or a wide band if a dyne is not possible. Somewhere at or near 11.5-12.0 at WOT is what we strive for.
BUT we also look for a straight curve all the way through the curve. Every engine is different and needs a different ratio in some respects. Some race teams run as lean as 13.5 or leaner. But for a street driven engine i would stick with the above numbers, Forced induction engines run richer by nature to control detonation ETC, Bottom line is trying to get it as flat as possible and around 12.0-12.5. Just my $.02
what is a wide band monitor and is it a tool i can use to measure with,, something i can add to my tool collection?
Here you go JAY this one is a good one.
http://www.americanmuscle.com/phantom-ii-airfuel-buttstuffog.html?utm_content=GSBasicFitmentV1&utm_campaign=51770545642-avshop&utm_source=Google-pla&utm_medium=Shopping&utm_term=&adpos=1o3&network=g&AMID=phantom-ii-airfuel-buttstuffog-GSBasicFitmentV1&year=2002&adtype=pla
I've forgotten, does the WOT table take the fuel trims into account?
i dont think son, Tom explained this a few years ago back when master blaster was around.
i suppose i could convert that to a shop tool but id rather have an buttstuffog unit.
Never saw this response to my post.....wish I'd have seen it sooner.
Kenne Bell has been making a speed density specific supercharger kit for the 5.0 pushrod motor for years. http://www.kennebell.net/KBWebsite/Pricelist_pg/links/PriceList.pdf
Part # TS1000-S. They also make another that uses a GT-40 lower. Also, I'll just leave this here: http://www.foxtbirdcougarforums.com/showthread.php?2028-forced-induction-and-speed-density
I will say this: looking back I may have been under the impression the car in question was/had an HO swap for whatever reason....
I know there was some issues with this car since and some work has been done to it. Did Scott ever find the reason for this phenomena before anything else occurred?
+1 on OP issue. Sounds overfueled not underfueled. Gotta have WB O2 to know for sure. I have had pretty good luck with Innovate LC-1 out of 3 units in 7 years on different projects.
what is the mk vii ecu do u need i have an 88 tbird with a so 5.0
we never figured it out.. the fuel pres was solid 39psi in the garage..
while in motion it never went below 34psi between first and second.... this told me all i needed to see.
anyway,, its a totally different engine now..... with one remaining issue we need to look at next week when he comes home. we believe an exhaust valve is not seating all the way after doing our leak down test.
Fuel pressure should always maintain 39 PSI at WOT... That is what's important, if it's anything less you're running lean...