...miles ir so. Short trips it runs? Hot weather seems to make it worse. Fuel pump, alternator, and battery have been replaced and catalytic converter has been eliminated. Runs great on short trips (5 miles or so). I've had it to 3 or 4 repair shops, paid the ususal $300+ for the work and I still have the same problem. Truck has 160,000 miles.
What makes a 1994 GMC Sierra with a 5.7L engine cut out after driving for 10...
- Thread starter Gary
- Start date
When it quits you need to figure out if its fuel or spark related.
When it quits will it restart right away or does it have to sit for a while?
When it quits is it sudden like you just turned the key off ? Or does it get weak and stumble?
When it restarts is all normal? or does it stumble a bit?
First check on the fuel side is fuel pressure. You can get a gauge for under $50 or many parts stores rent them cheap or for free if you buy the parts. For that engine you need the special GM TBI adapter, its a T, because there is no test port like most engines. Find a safe way to route the hose and tape it to the windshield if you have to so when it quits you can see if the pressure dropped. Follow the directions to hook it up. You have to unhook one of the pressure lines to tap in the gauge adapter. IF you dont de pressurize the system first you could end up with gas everywhere including your face. Usually with the engine running you remove the fuel pump relay and wait for the engine to die. Normal fuel pressure is 11-18 psi range.
For spark I would get a timing light. Same as the fuel pressure gauge (cheap to buy or rent). Get it hooked up and find a safe route out from under the hood and into the cab. It may have to be on the passenger side because the wires are not that long. Hook it to the battery and to the short spark plug wire that goes between the coil and the distributor cap. When it dies have someone squeeze the trigger and see if its flashing. A flash means you are getting a spark at least to the distributor.
THat should narrow down where you should be looking.
When it quits will it restart right away or does it have to sit for a while?
When it quits is it sudden like you just turned the key off ? Or does it get weak and stumble?
When it restarts is all normal? or does it stumble a bit?
First check on the fuel side is fuel pressure. You can get a gauge for under $50 or many parts stores rent them cheap or for free if you buy the parts. For that engine you need the special GM TBI adapter, its a T, because there is no test port like most engines. Find a safe way to route the hose and tape it to the windshield if you have to so when it quits you can see if the pressure dropped. Follow the directions to hook it up. You have to unhook one of the pressure lines to tap in the gauge adapter. IF you dont de pressurize the system first you could end up with gas everywhere including your face. Usually with the engine running you remove the fuel pump relay and wait for the engine to die. Normal fuel pressure is 11-18 psi range.
For spark I would get a timing light. Same as the fuel pressure gauge (cheap to buy or rent). Get it hooked up and find a safe route out from under the hood and into the cab. It may have to be on the passenger side because the wires are not that long. Hook it to the battery and to the short spark plug wire that goes between the coil and the distributor cap. When it dies have someone squeeze the trigger and see if its flashing. A flash means you are getting a spark at least to the distributor.
THat should narrow down where you should be looking.
Molson02536
New member
Start with the simple and replace your fuel filter, the other issue also could be a bad ICM (Ignition Control Module). A bad ICM will tend to fail when it starts to get hot and as time goes on will fail 100% and the engine will not start at all. You can have the ICM tested at more part store like Auto Zone and here is a link for you to retrieve your DTC codes for your Sierra.
Good luck and keep us posted.
http://www.troublecodes.net/GM/