5.7L question

[wheelinscott]

So i have a friend with a 89 5.7L TPI vette motor in his jeep. we are getting really frustrated because after it gets hot the motor will cut out, idling or driving it doesnt matter. we checked for spark its there. we checked the fuel pressure and its at 40psi. we have replaced the coil and the ignition control module so far. its also an aftermarket fuel pump that we think its from summit. and the pump runs even when it dies (its on a manual on/off switch)

so after it dies we let it sit any where from 5-15 minutes and it will start right up. and when he goes wheeling it died every 5 to 10 minutes. so what do yall think it is. we took it to a shop and they were no help. we are about to throw this thing off a cliff :explosion. any help is appriciated

TIA


(if this is in the wrong section move it por favor)

 

[yossarian19]

Has it ever shut off cold?
Ever fail to re-start?
I want to peg it on intermittent electrical...

 

[JJacobs]

To verify, the fuel pressure is at 40psi when it has the problem?

 

[projectTK]

why didnt u just put the stock vette pump in the tank instead of aftermarket? how the plugs look after it dies?

i have a 87 l98 tpi in my jeep so ur right up my alley.

 

[wheelinscott]

why didnt u just put the stock vette pump in the tank instead of aftermarket? how the plugs look after it dies?

i have a 87 l98 tpi in my jeep so ur right up my alley.

we are fixing all of the PO problems and half a$$ things he did to it.

when the engine dies the pressure on the fuel rail is around 40 psi. we also pulled 2 plugs and they had spark. when we checked for spark it fired and there was fuel pressure, but it didnt start.

it also hasnt shut off cold. yesterday we were letting it idle to heat up then take it for a drive and when it died we were going to check the pressure and spark, but once the engine got warm it died on its own.

thanks again for yalls help

 

[projectTK]

check compression, check if there is coolant in oil, check the worst most expensive stuff first. Do the plugs look rich?

 

[KRAKER]

Is it the motor with the dizzy behind the waterpump? They like to die often.

 

[Johnnie Walker]

Is it the motor with the dizzy behind the waterpump? They like to die often.

LT engines are the ones with the dist behind the pump.

 

[wheelinscott]

i think we figured out that it is the cal prom that goes in the ecm that is with the jeep. the po put it in wrong and fried it we think. i will update yall and see if that is it or not. unless yall think different. thanks

ya the dizzy is in the back of the engine next to the firewall