86 intermittent starting problem

[I_R_DA_ONE]

My 86 vette at times has a mind of it's own.....sometimes it will start and run fine but then other times ,,, the motor turns over but it will not start.... this is what I have done....I replaced the fuel pump with a new delco pump and strainer...replaced the fuel pump relay.....replaced the distributer pickup amp.... replaced the HEI coil...rotor button.. all the plug wires..and I am still having the same problem..... Is there something that I am missing that will keep the motor from running at times... Once on the interstate it just shut off and would not start.... I got it home on a rollback, then 3 days later I went out and it started up just fine... Yesterday I went to start it and it was the same old story....no start...The motor turns over good and I have spark but no fuel... What else turns the fuel off other than the distributer not turning and it picking up the pulses from the amp in the distributer???? Could this be an ECM problem??? The fuel pump relay is not being turned on when I am having this problem....
Thanks In advance
Mike R

 

[tigmaned]

what is your fuel perssure reading? ever pull the plugs to see if there wet with fuel? did you change the fuel filter too, i didn't see that it your thread? our vettes sure have alot of relays!! i was wondering how do you know the fuel pump relay is not being turn on, so if it happens to mine too!

 

[I_R_DA_ONE]

what is your fuel perssure reading? ever pull the plugs to see if there wet with fuel? did you change the fuel filter too, i didn't see that it your thread? our vettes sure have alot of relays!! i was wondering how do you know the fuel pump relay is not being turn on, so if it happens to mine too!

The fuel pressure is about 40 # and the plugs are all new...the old ones had very little build up and they were dry..yes the fuel filter was changed and the oil pressure switch was also changed.....the green/white wire on the fuel pump relay is hot when the relay is turned on...when I turn the fuel pump relay on everything works as it should..and the car starts right up....I am using the GM service manual for my information.... this problem is just intermittent that is why I am having such a time with it....and all the parts....
Mike R

 

[I_R_DA_ONE]

I am still looking for the answer to my problem

 

[larry bud]

My 86 vette at times has a mind of it's own.....sometimes it will start and run fine but then other times ,,, the motor turns over but it will not start.... this is what I have done....I replaced the fuel pump with a new delco pump and strainer...replaced the fuel pump relay.....replaced the distributer pickup amp.... replaced the HEI coil...rotor button.. all the plug wires..and I am still having the same problem..... Is there something that I am missing that will keep the motor from running at times... Once on the interstate it just shut off and would not start.... I got it home on a rollback, then 3 days later I went out and it started up just fine... Yesterday I went to start it and it was the same old story....no start...The motor turns over good and I have spark but no fuel... What else turns the fuel off other than the distributer not turning and it picking up the pulses from the amp in the distributer???? Could this be an ECM problem??? The fuel pump relay is not being turned on when I am having this problem....
Thanks In advance
Mike R

Could be an ECM or chip. When the fuel relay won't turn on, do you know if you're getting voltage to the relay?

I had a real tough time last year for about a week where my 86 would run like crap, then sometimes die for no good reason. Turned out the Prom was bad (ECM was OK, though).

BTW, the font, size, weight and color that you use is REALLY hard to read. I nearly passed it up because of that.

 

[I_R_DA_ONE]

Larry Bud
I did check the voltage on the fuel relay and there was none....there is no oil presure when it dies so the oil pressure switch is open....I have a complete ECM as a spare so tommarro I will carry it with me and if it dies I will change it out...
thanks for the idea
Mike R