ericnem

OK, I know this has probably been beaten to death here but here it goes. 89 IROC, 350, TPI, all stock yet. Cranks fine, catches and runs for about a second then dies. If I feather the throttle it will stumble along but not good enough to drive. If the throttle is in motion it will keep running but if I stop the throttle in any position, idle or WOT, it dies. It only runs if it is moving. If I unplug the MAF it actually starts and stays running. Runs rough, but it runs good enough to drive to the local repair shop, but I would not drive it very far like that. Started doing this a couple weeks ago. Here is what has been done so far:
1. Unrelated reason, changed fuel pump and filter and fuel pressure regulator last year.
2. Checked TPS, working and set to .54V at closed/idle
3. Removed throttle body and cleaned IAC and all passageways etc. Not sure how to actually check if IAC is working.
4. Checked fuel pressure stays at about 48 entire time.
5. New rotor and cap. (Plugs and wires less than 4000 miles ago but honestly I have not checked them)
6. Timing good, 0 with the brown wire unplugged
7. Took to the local shop, they said my intake manifold gasket was leaking some oil and I needed new injectors. Replaced both yesterday, much to my disappointment, same symptoms after completion.
8. While I had it all apart, I replaced and double checked all vacuum connections, everything seems in order.
At this point I do not think it is a fuel issue since almost the entire system is new (but I could be wrong). It puzzles me as to why it will stay running with MAF unplugged. It gives me no error codes (except when I unplug MAF). Any and all advice is appreciated. Thanks.

shep236

if its not fuel an air than its gotta be spark. my 91 formula runs good til it gets warm. i'd try the pick up coil under the cap on the distributor and or a new coil, could be not burning the fuel an when you unplug the MAF its getting enough air to burn it a little bit. check your oil to see if theres a hint of gas in it.

ericnem

Another thing tried today. Swapped in new Ignition Control Module. Did not help.

smoove2022

have you resolved this issue yet? i am having the same problem however it will run for a minute or so then die. with the maf unplugged it stays running but it runs rough. this is after i swapped out my baseplate and runners for edelbrock units.

ericnem

New MAF solved the issue, runs like a champ. Especially with all the other new parts I put in.

Gunthrock

Well this is a new twist and I could use some help I have a 89 I ROC and with the TBI 305 it locked up so I got a 383 off a friend put a 4 barrel carb and hti dist on it + a fuel pressure reg trying to bypass the CPU the car starts right up runs grate for 2 min then starts running really rough and will die out
did

Bustionironi

iTrader: (2)

Check MAF sensor relay. Check heat sink on ignition coil.

Tuned Performance

iTrader: (92)

Check the date posted, it’s fixed by now

Bustionironi

iTrader: (2)

Weird, it was near the top of the first page of this forum... and I recall it saying the date posted was 7/27/20. Maybe I’m going senile.