88iroctpi305

ok so i have an 88 iroc with the 305 tpi i have put a new fuel pump, fuel pump relay, fuel pressure regulator, alternator,starter,cap,rotor,plugs,wires,oil,oil filter, ignition module,throtle position senor,and fuel filter.i also have a brand new coil but just have yet to put it on..when i fire my car up it starts right up idles for about 5 seconds then it dies. i drained the gas tank and put fresh gas in it. and poured some sea foam in the tank hopping to clean things out a lil bit. she sat for three years before i got her. but after i got the car she still fired up and ran real good,even with old fluids and with all the old parts on it that i mentioned above. those are now like i said replaced and brand new... does anyone have any advice on this? i would greatly appreitiate it if i could get some input. thanks

88iroctpi305

ok so put the new coil on and the idle air control valve and still the same thing..?? does anyone have any input on this...? maybe the computer neeeds replaced ive read that on here a few times for similar problems...

Sighman

Any codes? I'm fighting the same sort of thing...how about starting fluid, does it fire on that? whats the pressure at the rail?

88iroctpi305

as far as codes go i have no clue.lmao. havent hooked it up to a computer yet. but it will fire it just doesnt wanna stay running. and i havent checked the pressure since i put the new regulator on. ill check that and get back on here to let you guys no.. i have a guy that is gonna hook it up to a computer and give me the codes for free. so that deffinatley helps out.lol but other than that does any one else have advice? im practicly begging now.lol

88iroctpi305

can any one help please?

scamaro355

hmm... sounds like aout hte only thing ya havent replaced is the mass air flow... which could cause that.. id also be looking at the wiring, if that thing sat around for that long a mouse mighty got hungary and chewed a wire or 2

88iroctpi305

thats what i was thinking... the mass air flow sensor or the computer... but when i got it it ran fine. needed a tune up but still ran good. thanks for your input. ill have codes up in about week or so.

ASE doc

Read codes. Look for an issue with the VATS system. The other system that comes to mind is fuel pump control. After start up, the FP relay turns off and the pump is powered through the oil pressure switch.

GM changed designs about 88 and went from a seperate switch located on the side of the engine, just above the oil filter, to a combination switch and gauge sender. Look under the hood down at the oil filter. Just above it you should see the switch with one orange and one tan/white wire going to it. If its not there then you have the later style which is behind and below the dist. Have fun with that. You pretty much have to pull the dist to replace it. There's just no access. I think you have the early style. You can test it by disconnecting it and placing a jumper across the terminals. Be careful because the orange wire is battery+. The fuel pump should come on. Start the car. Does it stay running? If yes, replace the oil pressure switch.

88iroctpi305

ok thanks. i have a new relay,and pump and the pump wouldnt prime, had bad connection at the relay plug;fixed that still didnt prime,so it was wired to a switched ignition thinking that would get it to run,because like i said it wasnt primming. but now it is. and it fires runs for a second or two then dies.

EFIhead

If it ends up being a bad ECM it's around $120 from rockauto for the ACDelco part which isn't too bad for what it is. Have you tried disconnecting the MAF and starting it? That would put it in open loop mode and if it stays running than its a bad MAF.

88iroctpi305

my brother told me he can get me a remanufactured ecm for 80 dollars. (he works at advanced) and no i havent tried that. so if i try disconecting the MAF and it doesnt stay running would that be the ecm?

EFIhead

I have to say so. You seem to have covered everything else. So run the test when you can and see what happens.

88iroctpi305

ok great.lol. thanks alot man. ill let you guys know whats going on with her tomorrow. its a little to dark right now to crawl under the hood.

slowpoke

Have you pulled the codes yet? Third Gen Tech FAQ has a right up on getting the codes. https://www.thirdgen.org/service-eng...ht-error-codes

If it doesn't do better with maf unplugged, try checking out or changing maf power relay.

88iroctpi305

No I haven't pulled any codes yet. Thanks for that link. And ok I will try that after I figure out what it is tomorrow. Ill proly just end up replacing that too if I have to replace the MAF

88iroctpi305

Okay so I just went out and unplugged the MAF and holy ****! she runs (sorry its been awhile since i heard her running)lol so hopefully i can get into advanced today and get the new MAF. thanks for all your help guys. ill keep you updated throughout the process. Thanks again!

ASE doc

MAF system failures are often not the MAF sensor itself. Read codes as was suggested. Simply jumper terminals A&B of the ALDL connector. Then perform the test sequence for the MAF code you find. You can find the test description by searching the tech boards. You may get lucky replacing the MAF but you will likely end up chasing your tail unless you pinpoint the problem.

alexiroc

Wow. I just ran into the same problem.
Been driving around with a fuel pressure gauge hooked up, all is normal, with a timing light hooked up, all is normal, so I am getting spark and fuel pressure. Hmnn...
With MAF connected, cars runs for 5 seconds then dies, the computer gives me NO codes (other than the standard "12"). No check engine light. So I disconnected the MAF, the car runs and continues to run but after 5 seconds the check engine light goes on. I have thoroughly tested both MAF relays, so now its a trip to the auto store for a new MAF. Keeping my fingers crossed.

Thank goodness it is not fuel pump or ECM.

alexiroc

That was it, it was the MAF sensor. So glad I read this post ahead of time.