I have a L98 in my 87 iroc-z28 5.7.. At first it didnt even start then i changed the fuel pump and fuel relays and it cranked but turn right off so i replaced the fuel pressure regulator now it cranks and start excellent but then dies out. I checked the spark plug wires and them in the right sequences now it starts up but turns off unless i step on gas pedal Rapidly it will stay idleing from 30-65 then when i stop pedaling it dies out also when i push gas pedal all the way in.. I have a video of it but i cant seem to upload to here. If you want to leave email or pm it il send you video so you see..
Im thinking its getting air or something but ive checked and i cant seem to find the problem, i was told its fuel pump again but, if it was it wouldnt be giving me excellent pressure.. But i dont know thanks guys

 

are you getting injector pulse with a noid light ? sounds like if you are pumping the gas pedal you are running off pe. you might have a issue with the icm not providing the tach signal on pin B5 of the ecm.

 

Any codes???

 

Yes i have pulse on all connectors.. What would be the pe? That is running off.

 

When i connect and scan it says. No codes have been recorded but engine light is on.

 

Maybe your scanner doesn't work on OBD1?

 

on every other car with obd1 ive had it worked just fine. but with this one it doesnt give me any codes at all.

 

pe is power enrichment like a accelerator pump shot off tps feedback.

 

Maybe try the old way, just say'n.https://www.thirdgen.org/service-eng...ht-error-codes

 

so what would you suggest on changing?
i can send a short video of car so you can hear the engine. just pm me your email

 

i seem to have found the problem.. i had the four bolts in the front where the throttle is loose and it was getting air thats why it would shut off.. so turns on fine and stays on by its self now. BUT idles like crazy and when i push gas pedal it chokes and dies out,, any help??

 

what is your base timing set too with the est disconnected ?

 

Now that question i dont know the answer to. Ive been working on it all today.. I replaced plugs and wires. Now it stays on good but idles between 20-45 sometimes higher.. It also backfires now. (muffler is cutt off due to replacing fuel pump)..

But i do no know about timing on these cars. Neither do iknow if my wireset is in the right sequence.

 

Also the deal with gas pedal is still going on, i pump it or step on it and it chokes down, (doesnt react how its suppose to)

 

the firing order is 1-8-4-3-6-5-7-2 in a clockwise rotation of the distributor. The timing should be 6d btdc with the est disconnected.

 

2k ? - 4,500 rpm ? start checking for vacuum leaks.

 

I do hear like a vacuum Leak but it also sounds like a bearing in the alternator is bad or dry.. Deal is this car has been sitting for 7yrs and im trying to get it running.. I will upload pictures of a hose that isnt connected to anywhere, it comes out of firewall, then another little little one that is from the egr solenoid..
I will check sequence..

But timing i dont understand haha im sorry thats my confused part, idont know how to check it thats the only part im stuck on

 

you might want to use propane enrichment or carb and choke cleaner to find any vacuum leaks. Be cautious and keep a fire extinguisher handy just incase.