ok i i have a 1995 gmc jimmy?

[pelcos]

i have replaced fuel pump and the coil and the modull and the crankshaft sensor and a fresh tune up and it still cuts out sometimes it runs 2or3 hours and other times less and cuts out and if you wait awhile it will start up again what is making this happen
ok have replaced the modull under the cap and it does have fuel and spark but i did not do the fuelfilter

 

[LeAnne]

Sounds like you've replaced about everything.
Now you need to do what you should have done in the first place - determine if it's a fuel or ignition problem when it quits and won't start.
Added: For one reason or another, these vehicles will not start or run with less than 55 psi fuel pressure. The test port is near the firewall at the back of the engine on the fuel line.

 

[bandit_60]

sounds like you should have changed the fuel filter too.also after you get done bleed the air out of the fuel lines.

 

[goldwing127959]

Remove the Control Modul inside the distributor and have it tested. this device controls the spark. It has been noted that when it heats up it quits. After it cools off it restarts fine.

 

[Molson02536]

i have replaced fuel pump and the coil and the modull and the crankshaft sensor and a fresh tune up and it still cuts out sometimes it runs 2or3 hours and other times less and cuts out and if you wait awhile it will start up again what is making this happen
ok have replaced the modull under the cap and it does have fuel and spark but i did not do the fuelfilter

Look's like you have everything covered other then the fuel filter. Once the fuel filter has been replaced, inspect the ground wire from your fuel sending unit. The ground is grounded to the frame and is common for it to corrode causing a bad connection. Also try swapping out the fuel pump relay, i believe it's located in your glove box behind and panel labeled Relay. There should be three of them there and i think it's the middle relay that's the fuel but not sure at this time, regardless. Try swapping them out and see if that helps, the relay could be running hot from a bad ground making it stick and not activating your fuel pump.

Another area to test is the fuel injection pulse, there should be 6 wire leads to the CPI. You can check them for pulse if your up to it and also inspect your wire leads to the coil, a weak coil will cause a weak spark and may not fire up the engine. Good luck and hope this helps, keep us all posted.