1990 suburban dies after 30 seconds

[SubGemini]

I have a problem with my 1990 Suburban. After turning off truck from a drive it will start again but dies out in exactly 30 seconds. It will start again but dies out 30 seconds later. After about 2-3 hours it will start and run fine again. I have replace the ignition module and fuel filter twice with no luck. This happened a few years ago and couldnt figure it out then either. One of the CK5 members said to change the Distributor. I did and that work for about a year. Could it be the distributor again??

 

[ccarley]

Hard to say, but sounds similar to a problem I had with my '89 Sub a while ago.

Turned out that the pickup in the distributor was going bad. Pretty hard to test though. It required the dizzy to be pulled to replace, but the good news is the part is really cheap.

We found the problem using a timing light... the light would shut off before the engine did; thus it was dyeing due to no spark

It was such a random problem though; the pickup would work sometimes, and not at others. No check engine light either; no codes stored. Engine would just die.

Good luck! Hopefully others will chime in; it's hard to say what exactly the issue could be. Make sure to test everything that you can though!
Clay

 

[SubGemini]

Thanks, Thats kind of what I am thinking also. I will try the timing light test and see if I can duplicate that. This is very frustrating.

 

[m4]

Did you figure out what the problem was?

 

[SubGemini]

Yes I did. Thanks for the all the help. It was the computer. I replaced it cause it was the easiest and that fixed the problem. That was so a pain to figure out. Thanks to whoever posted that they thought it was the computer not sensing the right amount of oil pressure and shutting down the truck after 30 sec. I knew it had an good pressure so I replace the computer. Whala. ;-)