New to NJFBOA - starting issues

[1991z28ragtop]

I am new to this site and it was suggested I get started by posting in the lounge. I sought out this forum because I have problems with my 1991 Z-28 when attempting to restart it after it is at operating temperatures. It has a TPI 383 with a 5 speed. I believed the problem to be in the ignition and removed all aftermarket parts Accel coil, cap etc and replaced everything with stock GM parts including the distributor. Then I was suspect of the fuel system, sometimes I hear the fuel pump and sometimes I don't when restarting. I put a noid on the fuel injectors and somtimes the signal is strong and somtimes its not. I have had every diagnosis under the sun from possible vapor lock to a bad fuel pump relay. I am only trying to narrow down my plan of attack by someone who may have experienced this very problem and has a suggested fix. I have an ATI procharger with three core intercooler sitting on my work bench which I will be installing this winter and will be biting the bullet on a complete ignition / fuel management system computer programable. I just don't want to be going in circles with this issue when its a common problem.

Thanks 1991 z28 ragtop

[deadtrend1]

Welcome

Whats the problem your having, just not starting up when warm? Like heatsoak on the starter maybe? Or its just spinning and not trying to kick over?

[1991z28ragtop]

It turns over normally but just won't fire up. I checked the vats thats not the problem the wire at the bottom of the steering column is in tact. It's as though their is no fuel but I have fuel pressure. When I replaced the distributor it stopped for a short time and then resurfaced.

[NastyEllEssWon]

did you replace the little coil in the cap?



have you taken a look at the vehicles cpu? could be bad

[1991z28ragtop]

Yes I replace it with the stock GM coil and the pick up.

Thats what I'm thinking the CPU is bad thats why I'm going with the aftermarket computer programable one not only because of the supercharger but for the fuel management. Hope I don't have this problem after replacing all that.

[BonzoHansen]

You put a new distributor in it?

[chrisfrom nj]

welcome

[V]

Originally Posted by 1991z28ragtop

and replaced everything with stock GM parts including the distributor

Originally Posted by 1991z28ragtop

When I replaced the distributor it stopped for a short time and then resurfaced.

Originally Posted by BonzoHansen

You put a new distributor in it?

Fail at reading



oh and welcome lol

[Knipps]

[BonzoHansen]

Originally Posted by SmokingSS

Fail at reading



oh and welcome lol

I saw that but just wanted to verify the whole dizzy (and actual NEW) was changed and not just the stuff on top - pickup coil taking a dive can act like this.

[Tru2Chevy]

First off, Welcome to the club.

I don't know what aftermarket engine management stuff you are looking at, but I would try swapping your computer out for another stock one first to see if the problem goes away. I would hate to switch to a completely new engine management setup only to have the same problems.

Always a good idea to troubleshoot fully before throwing (expensive) parts at the problem.....

- Justin

[sweetbmxrider]

welcome

[SRGN]

Measure the resistance of each injector when the no start is occuring. The stock ECM in that car is bank to bank, a shorted injector will pull down the driver and kill/weaken injector pulse.