I'll start at the beggining. it is a 88 Formula 350 TPI.

About a month ago it started randomly cutting out for about 1-2 seconds, with no pattern. Finally it died and would not start. Waited about 30 min and it cranked back up long enough to make it home. I have replaced the whole distributor, and ignition coil. It did not help. I found the engine ground very loose and tighned it. It did not help. I tried unpluging the MAF and it did not help.

So the current state of the car is that is will fire up but only with me on the gas and it runs like ****, then will die shortly.

suspect::: ESC module, bad ECM, Flux Capacitor


I'm stuck. I really could use the help

 

Maybe your fuel filter is clogged ? ...Or bad fuel pump ? ...Get in it , and turn the key , dont crank it , just turn the key and see if you can hear the fuel pump , it will be a slight humm sound . If you dont hear it , its most likely your fuel pump is on its way out . This maybe a stupid question , but have you checked your plugwires and sparkplugs ? If your fuel filter has not been changed for awhile change it . This may not fix it , but it may fix it .But a new fuel filter will make your fuelpump last longer b/c its not working as hard (less strain on it) . Did you check your ignition control module ? Goodluck !

 

Thanks for the reply.

But the plug wires are less than a month old and I already checked them for burns. The Fuel Pressure is holding steady at 48psi, so I doubt it is the filter is cloged or I would see some pressure drop.

Any other ideas??

 

Sure , No prob . I wish I could help you though dood .....This is a tough one ! Im kinda a rookie at working on cars , but Im on this board reading alot and learning and I have diagnosed some of my own problems lately . Im going to do a search on a long thread of someone who recently had this probem . Let me see what I can find .

 

I know you said you replaced the whole distributor , but did you replace the ignition module ?

Check your codes .

Think your cat converter could be clogged ? Lightly tap it with a piece of wood WHEN THE CAR IS COLD , and see if you can hear anything . When my cat got clogged recently mine was runing like crap.

What about your EGR valve , could it be sticking ?

Look for wires , (not plug wires b/c we know their good ) but , look at the wires that run from your coil to your dist cap , are they arcing ? any kind of electrical wires which work with the ignition bad or acring ?

 

yeah new module, pickup coil, cap, and rotor.

Cat was gutted 5 yeas ago. No codes are being thrown.

EGR?? Possibly bad. but I think it would cause driveability problems not something like this. When it cuts out it is IMIDIATE, no studdering or anything. Even if EGR went completly closed or open I don't think it could cause it.

Could the loose ground have cause the ECM to go bad???

Keep them comming. I've been going crazy and need more points of view!!!!

 

how about the rotor button ???????

 

suspect::: ESC module, bad ECM, Flux Capacitor

hmm ...I dont wanna tell you to change one of these and then that not be whats wrong with it .b/c we both know those aren't the cheapest parts on a car lol .....I wonder if there is a way you can test them .But then again , Im sure you would have done it already .

I was thinking about this whole thing when I went to bed lastnight and something hit me in the bed , I started to get up and come post it . I should have !!! B/c now I cant think of what it was , but it will come to me .

 

I JUST THOUGHT OF IT !!! .....check all your vacumn hoses , if even one hose is crapped out , it can make you car run completely like crap ....I changed all my vacumn hoses recently , it ran much better than it did , and was not running that bad ..You will also notice and increase in pickup ! But Im sure you dont need that anyway !

 

Well, I tried again and noticed something. After I fire it up for a few seconds. The header primary tube for the front drivers side (#1) is stone cold. The other three on the drivers side are HOT. Passenger side is the excact oppisite front three are cold and back primary tube is hot.

So either I have a batch of injectors go out together or the ECM. (I'm guessing) Since the odds of the multiple injectors failing together is low I'm getting a new ECM tommorw. The loose ground could have killed the computer, by giving it a brown out.

I'll let you know how it goes.

 

Yeah, it does kinda sound like the computer from your last description. When mine went bad, it was intermittent. Sometimes the car'd run fine for days, other times it wouldn't even start. And it never threw a code either.

 

I used to have similar problems and it turned out to be part of the harness had melted against the block and was grounding -- shorting the ignition. Although I am having some idle problems now and am begining to suspect the computer for the same reasons you are.

bottom line -- find all the grounds and double check so you dont fry another computer or ignition component.

 

Good point. I'll spend some extra time looking for anything burnt.

I'm gonna Pimp NAPA cause I bougth that ECM in April of 99 and kept my recipt. They are honoring their warrenty and giving me another!!! So that kicks a$$!!!!

 

Problem not solved with ECM swap. I found the MAF burn off relay harness really corroded and the insulation falling off. So tommrow I'm off to a junk yard to cut me off a harnes.

 

if #1 and # 8 tubes are cold then your car is in limp home mode. something went seriously wrong and when that happens the computer goes to limp home mode and runs on 6 cylinders. my ride did that when i had an intake gasket leak. with the car shutting down like that i put my money on the spark module that is under the passenger console next to the ecm. its a much smaller square plastic box. it is over heating and shutting down. and after a few minutes while your sitting it cools down and will activate again. i had the same problem with a jeep of mine and had the same exact symtoms. check your codes and see what you find

 

ummm... that don't sound right...
I was under the impression that limp-home mode used input only from the TPS, CTS, and engine rpm for fuel and timing calculations. I can't imagine why they would intentionally design it to run on 6 cylinders. Anybody???
Val, you've got two fuses for your injectors. I assumed that one was for the right bank, and one for the left, but I could be wrong. And fuses are not something that is intermittent; either they are blown or they are good. But you might go ahead and take a look at them anyway, it can't hurt.
Also, your MAF harness may be causing the problem. Too much voltage to the ECM, or too much resistance in an output device can burn up the computer, if I remember correctly. Or something to that extent...

 

I had a similar problem with a 86 GMC pickup 305 4BBL.

it would run great and then for no apparent reason just die, no stumbling no running bad just die. after a few minutes it would start back up again, after it made me walk about 5 miles home it went to the shop to be fixed. they found a crack in the distributor cap that was letting the high voltage bleed into the spark control module side and momentarily shut it down. the last time it was too much for the module and totaly killed it, we replaced it and never had another minutes trouble with it.

 

Have you read the spark plugs yet? Then you'd know about the injectors... there's a way to do that flow test without buying the special "box"... I don't remember the details.. I think a diode was needed somewhere?

 

Well I found the FP relay with some bare wires coming out of the harness. So I went to the dealer and ordered a new harness and relay. $40 for harness and $15 for relay. The harness and relay are not the original kind, GM discontinued them. But after soudering in the new harness and putting everything back together. SHE FIRED UP!!!! BUT RAN LIKE ****!!!!

I adjusted the timming but didn't help. Pulled some plugs and yes they were fouled, but I had seen worse. I pulled them all and cleaned/regaped each. Put them back and VROOOOM!!!! She lives again!!!! I have the Accell U-groove shorty plugs and I don't think they are very forgiving. I have always used Bosh platinums before and not had a problem with them. I'll be switching back. Also I found some of the plug nipples had unthreaded themselves from the end of the plug!!! WTF??? Stay away from Accell!! This is my second bad run in with Accell ignition parts!!!

So I'm SURE the pickup coil was bad, because it had turned to goo. I think that was causing the cuting out. Having this AND the faulty plugs was what was screwing me around. Wasn't looking for TWO problems.

The FP relay I don't think was a problem but I'm really glad I found it!!! It was a short waiting to happen. I have some picks and I'll post them in a thread later.

Thanks Guys,

 

bravo..... :lala: