Ok - so here it is.... I have posted a few times with bits and pieces to my problems but here is the full list of what is bizarre and unsolvable thus far in my car in all it's terrible full fledged fury..
For starters - after a few moments of blissfully enjoying my too cool for words 1988 camaro (with few people knowing how little horsepower lurks beneath the hood via a 2.8 v6 mated to an automatic tranny ) My car begins its trek into the world of impossible mysteries.... when waiting at a stop light, sign, or stopping in general, once I have come to a stop and my car is to be idling... it doesn't. It will begin to drop to a very low RPM and rev up a few hundred or a thousand to normal idle, then drop revving up and down up and down then a final jerk forward by the vehicle and a stall. This usually takes place just as the light turns green or I have my turn to leave the stop sign. Now if I attempt to take a turn and hit the gas simultaneously, my car had an old problem, which left for a little while, and now is returning.. when I turn and hit the gas my car will sputter like gas/air is only intermittantly getting to the engine, in bursts so it'll go 3000RPM -> 2 RPMS -> 3200 RPMS and so on climbing slowly with large drops in between, until I straighten out again and resume my cruise. When it stalls out at lights a distinctive odor of gasoline will fill my interior, and my exhaust smells rich too. Frankly the low RPM rev/rich smell usually results in from the outside sounding like I have a hot cam setup under the hood. I don't. I've personally re-run almost every vacuum line I can reach without dismantling the intake manifold, yet I still hear a hiss sound that sounds like i have a really weak turbo or something. Again, I don't. It seems to be coming from the center of the manifold plenum. I've had the codes pulled once and they noted I was running rich. Thanks. It didn't help too much. There's also a large tube running from a 3 way vacuum damper in the back of the intake manifold plenum that runs down my driver's side wall of the engine compartmant that is plugged with a screw. It was that way when I bought it. Now, that's not up to factory par. I've gotten mixed responses as to what it goes to, from vacuum booster, to a T bar split where one half heads to cruise control (which I don't have) and the other half going apparently to a mystery. I don't know if this is the big problem, I am doubtful, but it's something I thought I'd mention.
The list of repairs I have done by hand thus far, not all seem relevant to this problem but i'm listing them anyways....
O2 Sensor, Intake Y-Pipe w/MAT sensor, Radiator, Thermostat, Vacuum lines, Coil, Rotor, Cap, Spark plugs, Fuel pump (used), Alternator, Intake Manifold Plenum Gasker, PCV Valve, IAC Valve, EGR Valve...
that about covers it. send me any and all ideas, i don't care how long this thread goes on for, I will read and reply to all ideas.
If you do successfully solve my problem, I will if you wish, send you a picture of me worshipping a picture of you. Thanks for your patience!

 

I've seen something similar to what you're describing when you say the car jerks forward and dies on another GM vehicle. The problem with the vehicle I had was that the torque converter would stay locked up and give the same results as stopping a manual car without pressing the clutch pedal. I'm guessing (and just guessing) that the torque convertor may be trying to lock up. You may want to try disconnecting the lockup system, if it's possible on these cars, to see if that solves your problem. I'm not familiar enough with the 700R4 yet to know, but just wanted to throw this out and hope it helps.

 

Iam having the same problem with my 305 v8 camaro. It won't keep a steady idle and wants to die like its getting to much fuel! Please give us both advice i have also replaced parts and still have the same problem

 

just another regular maintenance thing, you might wanna try replacing your fuel filter, and sometimes if you're running rich it's because of old leaky injectors.

 

Have you tried swapping in another computor? It looks as if the sensors have been done, see if you can locate a wreck in the bone yard of the same year.

I agree also, check your injectors.

 

Try unplugging the MAF (mass-air-flow) sensor right in front of the throttle body... See if any of the problems go away... If they do, it might be the MAF acting up and feeding wrong data to the ECM..

 

tried the unplug the MAF - didn't solve anything, which is why i didn't mention that i did replace the MAF as part of the Y-Pipe intake replacement, it was a pick-n-pull item, but they said they tested it out and it was working.. MAF going was my first guess when this all began, since i'm getting a bad MAF code when i pull them- i'm going to go to autozone tomorrow - i know a tech that has some kinda rare expensive scanner that reads and gets active updates from ECMs before and after 1996, active O2 readings and fuel readings and such... so hopefully more information then... with the code... in case it wasn't clear the CHECK ENGINE LIGHT is on.. maybe its the SERVICE ENGINE.... should be YOUR ENGINE IS F.U.B.A.R. light...

i can't tell how happy i am to see people actually trying to help me -- us i guess now -- this problem it's been plaguing me since I bought the thing almost a year ago.. tomorrow I'm also going to replace the fuel pump/tank gasket, since I don't think the one on there is any good... ( I went through the top with some welding/cutting to get to the tank to replace the fuel pump rather than the remove from underneath route.. good choice in the end, makes diagnostic and future work much easier ) but i doubt that's the problem -- i've taken time after having the rich gas smell to go, open the hatch, and roll back the carpeting there to see if it reeked of gasoline. which it didn't... so i don't think its the gasket... but never hurts to replace a gasket.. they're like $2...
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i'll also give a few calls around and check ECM prices.. since they can get up there in the $$$ range.. i'm a college student, by no means well-financed... so almost all of my work has been done by me, by hand, and in long intervals between major parts/sensors .. just giving more information on my setup! thanks to all again!

 

When was the last time you thoroughly cleaned the throttle blade(s)/bores? I like to use fuel injection cleaner in the spray can, and use an old toothbrush to get the gunk off.
You should also take the time to clean and then lube, the throttle shaft.

 

I bought a rebuilt ECM just a few days ago to see if the problem would go away...... but It's still plagued Iam a college student too and didn't want to invest too much incase it didn't work, so I only spent $80. If it works buy a new one later, just a thought!

 

I had a scan done, active scan at autozone... still don't know what kinda of kick *** scanner this guy has.. but my MAF sensor is all over the place as is my TPS sensor, neither are running enough voltage.. but there are some other strange things in the vehicle that make me wonder what it is...
I've basically narrowed it to 3 final repairs before selling the damn thing (which i have fought tooth and nail against doing)

1) TPS
2) ECM
3) MAF

I have always been suspect of the TPS... so that's my number 1 culprit... but quickly gaining and looking to overtake the number 1 spot is my ECM. When my fuel pump broke, it was due to a short out I believe since my trunk closing motor went (and recently repaired itself unbeknownst to me.. strange) and the fuse in my amp in the back went too. I know there was a short in the system, since I repaired it myself. Bad ground from the battery. Now maybe the short there blew my ECM, who knows. Also reasons to suspect my ECM is that my odometer won't work, and my tachometer is bizarre. By bizarre I mean that at idle it reads about 750 RPMs too high, then as I accelerate the gap between actual RPMs and what my tach reads grows. (again this is more information I came across as I active scanned it) This means that as I accelerate from say 1200 RPMs to 3500 RPMs (in the engine - read via scanner) my tachometer reads 1700 RPMs to about 6000 RPMs. The gap between actual RPMs and Tach RPM display grows farther as I accelerate. Also, my fuel gauge is skittery (sometimes it works and sometimes it doesnt), my temperature gauge randomly will either look flatlined or top ended. Sometimes i'll start my car from cold and the temp gauge will read way high. Other time it will just not move from well below 0. So My gauges are all fakhat (it's hebrew - but i'm not jewish) - another reason to suspect my ECM. But in order to make my TPS remain as the number one suspect, while my idle is rough and low and rich smelling in park, it never stalls out when in park. Only when in drive will my car stall out -- which is why my present driving solution is to put my car in park at every light... MAF is at the bottom of the list because while i am reading codes that my MAF is bad, I have tried the "unplug it to engage limp home mode" test, and with it unplugged it runs the same as it does plugged in. However unplugging my TPS sensor makes my car stall anytime you hit the gas. This I found kinda strange. No "limp home mode" for the TPS... unless maybe i'm already in it! so there's the full update THUS far - any opinions or further tips would be awesome, thanks again for helping out with opinions and such as this saga continues..

 

I think you are barking up the wrong tree with the ECM. All of your gaues are driven by sensors, in some case the same sensors that provide signals to the ECM, in no instance can I think of a gauge that is driven by or fed a signal from the ECM. If your gauges are flaky it most likely means the ECM is receiving flaky information too. The one thing I can think of that would affect ALL of the guages in that manner (and possibly the MAF and TPS as well) would be a faulty or intermitant ground. DO a tps voltage check ( there is directions on the tech articles page) and also check to see that the engine is grounded to the chassis. Maybe someone more familiar with this particular engine can tell you exactly where to look, on the V8's there is a ground strap on the rear of one of the cylinder heads. good luck and dont give up just yet, we can find this.

 

Having identical problems with my 88 iroc if you figure it out PLZZZZZZZZZZZZZZZZZZZZZZZZZ tell me whats wrong. Only thing different that im getting on my codes is an EGR valve. Getting it thursday though.... hopefully it will help out. Dont really want to replace the 150 MAF if thats not the cause. Car runs the same if its unpluged. Also smells like the car is running rich. I have replaced filter and checked injectors and there ok.

 

first off i would just like to say that the useful and pertanent information that this site has helped me out with already blows all other online sources away - i wished I had joined up sooner! second of all, I had problem of old resurrect (with my car stalling out as I turn and then sputtering until i'm in a straight line) only this time i did not recover. I added gas and went alon my way, before I added gas however, my car could start and would idle (low and rough but idle nonetheless) so I'm thinking that this little section of the problem may be due to a screw up on my behalf. When I replaced the fuel pump i didn't replace the gasket (even though i know i should have immediatly - it says to very clearly in the Hayne's.. old gasket is useless) so at some point today - when i get the energy to, i'm going to pick up the fuel pump/gas tank gasket remove that whole assembly again, and put a new gasket on. The reason I think that the gasket is a culprit in the turning problem (not so much the bad idle/stall problem) is that if I have a lot of gas the pump is fully submerged, so pulling gas to the engine isn't a problem, but when it's low, it has to rely on vacuum pressure to get it to the pump, right? well if the seal isn't tight i'm mostly going to pull air through the pump. Add gas, resubmerge it, and I can motor away happily. So - off to autozone...

 

Ok one more thing that can make a HUGE differance in starting and Idle quality. CLEAN OIL! if you for some reason have been running rich ( I had a bad header gasket and dilluted my exhaust... fooled the O2 sensor into trying to compensate) it WILL contaminate your oil. Fumes from this are drawn through your PCV valve and it is near impossible to get a decent idle and it may even make it hard to start. Also PLEASE... Please check your grounding. if you are having ramdom intermitant electrical problems you will never nail this down by thowing parts at it. Also it wouldn't be a bad time to accomplish a complete tuneup.. plugs cap rotor, TPS voltage set, give your self every oportunity to single out A cause. TBI motors work as a system and try to compensate in strange ways. Good luck Data logging might help so that you could see what conditions existed exactly when you had the problem, i know it is a bit involved to get into but it might be worth your time. Check out the PROM burning section of the forums for more info.

 

I'm gonna take a stab at this. First off, it sounds like you have wiring issues. Second, I doubt your ecm is the culprit here. Your old intermittent problem with the car sputtering around corners could be caused by faulty wiring on the opposite side of the way you're turning. Centrifigal force has a way of pulling on things in a bad way. Third, if you've traced the vacuum lines and found no leaks, but you still hear a hissing noise, get out a propane torch and run it the length of your vacuum lines, and your entire intake manifold. If the engine speeds up, you found your culprit. Fourth, and most important of all, is that I think you're possibly suffering from various little gremlins that have cropped up over time and disrepair. Patience and time spent diagnosing would be a better course of action than just throwing money at parts you "think" might be the problem. Not trying to be a jerk, just trying to be honest and helpful. Running each problem to ground will be far more beneficial than guesswork. If you feel your confidence wavering, just put your most determined face on and say to yourself, "I can fix this thing." By the way, did you get any other codes?

 

i've run through the majority of the elctrical grounds, and while I thought that was the culprit when my car first started to die before the fuel pump, it was because it was doing it to just one side, however, now it's doing to both ways i turn, and it also runs normal again once gas was added... so i still need to find that fuel pump gasket... i had no idea how many people were suffering from a similar problem! I am however about due for an oil change and it's funny you mention oil in the PCV, because my PCV valve is coated wth oil when I removed the old one.. I haven't been throwing money at it, believe you me - it takes money to throw money at something , before I even started doing parts replacement I ran through a good 70% of the ground wiring system with a circuit continuity/ground tester (brother in law is an electrical engineer - comes in handy for those problems) so I'm les inclined for the ground out problems, and I am starting to suspect the ECM less.. the codes I pulled were bad TPS and bad MAF.... which when my car died out the first time what happened (I believe) was that a ground shorted out the majority of my system, and that coulda damaged all my sensors. Reeason I think it shorted out was that was when it was doing the sputter thing to just one side, also starting it back up after it stalled out before was an issue, now it starts up, but won't gas (again I think due to lack of vacuum in the fuel tank making it so the fuel pump can't suck anything up once it's no longer fully submerged) , also before I did find a horrible ground from the battery to the car, which I immediatly replaced with a large heavy duty wire. I think that a big short kiled my old fuel pump (i dont knoiw if i mentioned this) because when replacing the fuel pump that was shot, I also discovered that the fuse in my amp in the rear of the car was shot and so was my motor for my rear latch (which actually started working again on it's own recently..) so I guess that a short out blew everything back there, hopefully I found that ground and replaced it properly, before it was dying when turning to one side, now it dies to both, and the light don't flicker all of the sudden like theres a bad ground, it just seems like the engine is getting intermitent bursts of fuel...

 

If I read your post correctly, you stated that you have an amp hooked up in the back. Did you also get an alternator to handle all the extra equipment you're running. And the thing about the wiring, it doesn't have to be a ground necessarily. That's why I suggested checking it all. If this is a T.B.I. motor, which vacuum hose is disconnected?

 

not TBI its MPFI also, yea the alternators new and better, but its not like it's a serious amp.. i don't blare it, I just needed something to get better sound

 

Did you check and set the timing after the tune up. If your plugs are fuel soaked, I don't think fuel delivery is your problem.

 

sounds like lock-up solenoid

 

uhm, I am still wondering how a "short" can blow things up all through out the car, and if they were really and truly hurt by a reverse current condition, then they would not begin to magicly work again. This sounds like wiring problems. OR if things are realy being damaged I would do a voltage check on the system while it is running as your regulator Might be letting your system voltage go WAY high. mostly if you short out a circuit in the car it will blow a fuse and or a fuseable link, with associated smoke and heat, but very rarely if ever will it hurt anything else. as it wont actuall be a reverse current situation it will be a +12 volts on both sides of the device. no current should flow. anything that wide spread in the car I have to suspect electrical, like you have shorted the regulator and caused a high voltage condition, or somewhere in the amp install/alternator swap/ stalling you actually reversed polarity either with jumpers, the alternator or the battery. My point is ..... you have a LOT of electrical items failing... Hatch pulldown, amp fuses, Fuel pump, seems like a place to start.

 

first thought here too.

 

too lazy to read the whole thing but here are some things to think of

torque converter easily isolated. when it sputters and wants to die put ithe car in N. if it runs and idles just smooth as can be chances are it might be bad. if it still runs like shize you prolly have a vacuum leak.


put a vacuum gauge on the car. might give some idea there as to vacuum leak.

fuel pressure gauge. start the car up watch the gauge shut the car off watch the gauge should hold pressure. it doesn't? check your injectors and fuel pressure regulator. it does? check your fuel filter.


would talk more but the eve is trying to corrupt the serpent.

wait shouldn't it be the other way around? oh well

 

i don't think it's the torque converter because it doesn't feel like a clutch slippage, it feels like intermittant bursts of fuel/air as for the electricity I did test all the circuitry when replacing the fuel pump and I was pulling +12 volts until I fixed the ground. It was just a shot about a short out.. I remember before I checked the electrical system and the fuel pump, it turned off very suddenly when I went over a large bump, the whole car just stopped. Engine shut off, power steering/brakes went, lights flickered dimly then lit normal, had to throw it in nuetral and let it glide into a parking lot. But since then I redid most of my electrical systems and wirings (grounds especially), after doing a few more tests it definately seems to be in the fuel delivery department, this weekend I get paid, so I will replace the remaining bad parts (MAF, TPS), take some more measurements (vacuum measurements, fuel pressure gauge - because I still haven't ruled out a leaky injector/loss of pressure/filter/regulator problem), re-do the fuel pump area (use the proper gasket, make sure it's set in the tank properly and all lines are sealed), double check the grounds and circuitry and try and discover where the screwed shut vacuum line goes.. and then pray that this is where the saga ends!! brace for big finale!

 

since the short out that i mentioned in the previous post I haven't had any problems with shorting or anything else not working/blowing... now that you mention it though, when installing my alternator, I let my dear girlfriend screw on one of the remaining bolts whilst I answered the phone, she knocked one of the battery terminals back onto the battery, the shock scared her, and she dropped the wrench across the alternator (now plugged in) and the metal EGR tube (which melted a whole in the EGR tube which needed to be JB Welded over because they don't SELL that part anymore) and there was definately an electrical surge there! but the polarities are fine now.. my only guess as to a high voltage situation. I stopped suspecting a short out too when my hatch motor was working again mysteriously. It still is, but again, I'm trying to get all the information I have out here for discussion

 

You can check your torque converter real easy. Just cruise down the street and when the drops into OD, with your foot still on the gas maintaining your speed gently apply your brakes (not enough to slow the car down put past making the lights come on) if the car comes out of OD (RPM's will increase) then the converter is fine. but it sounds to me like maybe its the alt. or some arching plug wires.


You might just have to get wiring dia. for each thing that was working and is not now or is working and was not earlier.

 

torque converter is good

 

Just to throw in my two cents.It sounds like multiple problems.The rear hatch is probably a switch in the pull down mechanism being intermittant.I've been there with that.The engine may be a weak distributor module.I've been there with that too.The engine would sit in park and just about die and then rev up to 1000 rpm and repeat.It did this occasionally but not every time I stopped.Drove me crazy for about a year.Anyway just a thought.Good Luck

 

Try the EGR valve. Had very similar problems. Put mine in today no more problem.

 

Check the tps....my 350 was doing the same thing. I swaped in a good MAF with no change. Did not idle, was a beast to make move from a stop, on the highyway it was angry. I checked the tps as a kind one from here suggested and then rechecked next morning to be sure and then replaced it and all is still well.

Do a search, there is a post here with the instructions for checking and for setting the new one. Not hard just a pain if you only have two hands....even a wife or girl friend will do in a pinch and you need a digital multimeter. Need one for these cars anyway so now may be a good time if you don't have one.

If this works I don't need to be your God, just send some beer and women (no fatties). Seriously hope it helps.

 

try checking the fuel pressure regulator see if it holds pressure or is leaking the line off the back of the intake goes to the power booster i would also try pulling the whole plenum system off and cleaning it up and replacing those gasket may be getting a vaccum leak from one of them could also be bad injectors

 

can someone post a picture of the vacuum power booster that the line that comes off of the back of the plenum goes to? I described the fact that my line goes off the back of the plenum and is plugged with a screw... which I know is wrong... I get paid hopefully by sunday and I got a few days off, the first thing I am doing is double checking my fuel seal and putting on a new TPS.. results posted soon!

 

yea my car did the same things two times one was the fuel pump only putting out 5psi and the other was the intake air temp. sensor.

 

Had to finally take my car to the dealer and the fuel pump had also gone out in mine. It checked out at 5psi also.

 

alrite, so with a new MAF and TPS (however my TPS won't pull the .55 Idle volts it should - if I want it to pull .55 volts then it need to be pointing upwards at almost a 45 degree angle, which I simply cannot do), my car sometimes will start up, then immediatly go to idle and drop steadily in RPMs to stall in like 10 seconds. Then, if I quick shift to drive and run it for a little while my RPM drop problem goes away, and then it'll run merrily at highway cruise speeds until I leave the thruway. Then some new interesting problems come up, the old crappy idle rev up drop down rev up drop down then stall at a stopsign or stoplight.. then comes the weird stuff, if I hit the pedal at all i'll do this jump to high RPM (4500) in no time flat then drop to like half that then way up again on and off in a very interesting stalling out as if I am not putting enough gas to the pedal in a manual fashion (even though I have an auto), its the MPFI engine, then my check engine light will come on and my shifting will go wack as he11 and rev in between gears even though I am just driving at cruising city speeds, then I'll get it home, turn it off for a few minutes and turn it back on, then it runs somewhat normally, with the same hit the gas sputter issue, with backfiring happening on occassion.. not a good thing. so with all these issues here's the one problem I know needs work, my plug from my onboard into the TPS needs to be replaced. I know that. My seal around my gas tank/fuel pump meeting area (with the lock ring) could probably use to be replaced... other than that I have no ideas, I was thinking timing but then I remember that it's set electronically and the computer handles that...I think that I'm ready to resign finally... this car may be going up for sale. With all the misfiring and backfiring I'm getting going on, I don't think the TPS plug, gas tank seal, and new ground wire to the block will do it. But those are my last efforts. I'll do those three repairs, then if it's not working after that, I finally surrender to my possessed camaro of suffering.

 

hey don't give up!

 

just my two cents but check vacum leaks

 

ran through using propane for vacuum leaks, my vacuum system has been almost totally re-done, I ran the codes, and I'm getting codes for all the parts I recently replaced, talked it over with a friend of mine and I'm thinking and praying it might be the bad ECM - caused by a short out or something... it's my last major part I'm going to put on, if it doesn't work out then I'm buyin a red sign

 

The first step is to determine whether you have one problem or many.If everything happens at one time then it's one problem.If they happen at different times it's probably several problems.The TPS not reading an idle voltage is definately a problem and will cause major problems with the engine.There is no limp home mode for the tps that I know of.So that has to be fixed first.On my 2.8 the tps is pretty much level when it's adjusted properly.I would suspect that is one problem and you need another one.Also Don't take for granted new parts are automatically good i've run into too many bad parts that were brand new.The tach signal comes from your distributor and shouldn't have any thing to do with the other guages.Those should be troubleshot separately unless a power or ground are in common.But do this systimatically and in order a good running engine is most important.Check your fuel pump sending unit again.That might be your fuel guage and cornering problem.See if it's bent or damaged in some way.Check the sock on the bottom make sure it's clean.Any car can be fixed up if you take the time and effort.Good luck.

 

rhomenofski is correct ,but you could check the o2 senser ,this partly controls fuel usage

 

they're all at once type things, I replaced the O2 sensor already.. i think the first post has the list of new parts, this is why I'm starting to blame the ECM since they're all out of whack. and with the TPS when I install it I can't get the right reading unless I have the sensor at almost half throttle, I've already traded that TPS in for a new one, thinking the first new one I got was busted since I couldn't pull the reading then, then we double checked, made sure it was the right one, etc... then got a new one, and still having the same problem, so I'm doubting the problem actually being the TPS. And if I bought a MAF and 2 TPSs and they're all bad when I got them new? then I think there's a lwasuit in order for advance auto parts... but I doubt that be the case.

 

Everything seems to have been mentioned here but one thing.
I read somewhere about low resistance spark plug wires screwing up ECM communication. Measure them just to be sure, should be 2000 to 8000 Ohms.
I have no idea if this can be considered relevant for these cars.

 

One more thing I could recommend is to do a good visual on the wiring harnesses they can wear through the insulation usually in the hardest place to get too.Behind the block.A friend had that happen on a 92 rs drove him crazy for a year.

 

one more thing did you clear all the bad codes from before dont no how its done someone else did mine ,its theorticly possible the computer might think you still have problems try clearing all codes drive and pull again

 

That problem is pretty rare with newer cars and better quality plugwires...it was mainly a problem with old school solid-conductor wires, which yes, reek havoc with the ECM, as well as your radio usually.

I've seen fuel pressure brought up a thousand times, but no mention of its result. Have you checked it? Needs to be tested at idle to see if it's within specs, and then with the vacuum removed from the regulator. With no vacuum applied, it should climb anywhere between, I'd say 4-8 psi is typical. Idle fuel pressure, vacuum applied, should be somewhere between 40 or 45 psi IIRC. There should be very slow bleed-off in pressure once the car is shut down also, if the gauge begins dropping immediately, you have a leak in your system, either in the fuel rail, regulator, or one or more injectors (most common).

Also check the vacuum line to the regulator for fuel, either liquid or a gas smell coming from the line. This is a sign of a ruptured regulator diaphragm, which leaks raw fuel into the vacuum line, causing a rich condition.

Check your idle stop screw, it's possible your stop screw is way out of spec, causing the computer to try to compensate and maintain idle solely off the IAC valve. The screw will be behind the throttleblade, a flat part of the blade rests on it at idle. Check to make sure it's not cranked out way far either. The whacked out TPS idle voltage makes me think there's something very wrong with the position of your stop-screw.

If you know anybody that could get a scanner/scope hooked up to the computer it could prove helpful to someone who knows what theyre doing. Being able to actively monitor TPS voltage, MAF values, short and long term fuel trim, and lambda data from the O2 sensors can often give you a very good picture of what's going on in the ECM. For example, if you spike the throttle and MAF values change very little or don't change, it points to an MAF issue. Also a very low lambda reading on the O2's especially on acceleration can indicate a faulty MAF or connection not registering airflow, or insufficient fuel pressure or volume.

Hope this helps

 

Well as far as brand new parts go,my dad bought a brand new distributor once for a slant six.He couldn't figure out why it wouldn't run.His original distributor was bad but the one in the box was for a v8.All of them in the parts store were in the wrong box.The new owner figuered that out.I still see it driving around occasionally.

 

I forgot to mention, have you checked ignition timing? Low base advance could cause some of the issues you describe. IIRC, stock, with the EST connector unplugged, should be around 10 degrees on your motor.

And have you pulled plugs yet? If you haven't, do so and make note of what they look like and if there are any that look different than the rest, which could pinpoint a potential single-cylinder problem.

 

you need to do what alot of people are saying in here

but do it in a comprehensive order

1. timing
2. set tps
3. reset IAC
4. set idle
5. NO vacuum leaks (including from the base of the manifold, maybe even the PCV boot or that small plastic tubing that tends to break easily)
6. NO exhaust leaks, especially before the O2.
7. Check fuel pressure
8. Pull your plugs, see if any differentiate between each other. Clean and gap them anyways.
9. Check your ignition control module (ICM). It can do all kinds of sputtering things, and anything to do with timing can get it to smell like gas.
10. get that fuel pump sealed properly like you said.

anything else you can think of, you try to work in before it will affect something else you do, so it won't take all day.

do all of the free things first, and THEN throw money at it, starting with the cheapest parts that seem the most relevant to the problem. DON'T forget the small stuff (new fuel filter, etc.)

i'd check wiring for any janky lookin connections or crispy spots too

 

alright buddy I read it all. I've had every single one of these problems. Infact I had them again yesterday after I started my 88 350 tpi iroc after new engine and wiring harness. The problem with that was I had the wrong ECM (was running a 305 tpi ECM). Although previously the problems have been:
-fuel pressure regulator diaghram busted (would explain the sound of a vacuum leak seeing as how the fuel pressure regulator is vacuum powered. So borrow a fuel pressure gauge throw it on there and when you turn the key you should have from 30-45 lbs of pressure.
-Fuel pump which can also be checked the same way as the fuel pressure regulator
-A cracked manifold (that would really suck for you)
-TCC Lock-up solenoid, this is inside of your tranny. to check this unplugg the only electrical connection on your tranny. It should be on the driver side right above the shift linkage. What this plug does is when ever you are at certain RPMs the sensor there completes the ground through the ECM (basically overdrive to save you gas while cruising). It may be ingauging when your not moving or at low rpms which is the same as not holding down the clutch in gear when stopped in a standard (you'll stall). When I did it the plug check didn't help so I took it out and cleaned it. After that it worked great.
-Govenor, while you're down there in the tranny you might as well clean the govenor also its on the passenger side of the tranny. All you gotta do is pull it and push the end and see if its movable (if not you should get a new/used one) to clean spray it down with carb cleaner and a little brush action.
-Check your fuses (should always be the first thing you check) regardless of the problem
Don't be freaked out, this stuff really isn't all the hard. if you want you can give me a call and I can talk to ya about it alittle more 281-732-1342.

 

what he said gl