HELP!! FUEL PROBLEMS STILL!!

Tweeter400 · October 21, 2003

After my truck sits for awhile it is very hard to start. The service manager told me to replace the regulator, didn't work. Then he told me to replace the pump, didn't work. What the heck else is there?? It doesn't leak any fuel and I don't smell any fuel. Anyone have any ideas??

Thanks!

SportyShorty · October 21, 2003

Have you replaced your fuel filter? My dads 99 was getting to be hard to start and once it started it wouldnt idle for crap. I changed the filter and now it runs like a champ

dogzapper · October 21, 2003

I agree; sounds like fuel filter.

Back in the days of primitive rigs, I had a '78 Silverado that gave me fits. Turned out to be fuel filter (about the size of a cigarette filter) AND a kink in the metal fuel line. I eventually went to an big in-line filter and traced the fuel line to make sure it was all round.

Steve

jhm · October 21, 2003

Check/replace gas cap.

Tweeter400 · October 21, 2003

I apologize, I did change the fuel filter, twice actually and the flow direction is correct. Is there any way to test the gas cap to see if thats the issue?

asepgrad98 · October 22, 2003

Good chance your problem is on this list:

Hard start

Check the powertrain control module (PCM) grounds for being clean, tight, and in the proper locations

Check the engine coolant temperature (ECT) sensor for being shifted in value. Connect a scan tool. Compare the engine coolant temperature against the intake air temperature (IAT) on a cold engine. The ECT and IAT sensor values should be within ± 3°C (5°F) of each other. If the ECT sensor is out of range with the IAT sensor, check the resistance of the ECT sensor

Check the mass air flow (MAF) sensor installation. A MAF sensor that is incorrectly installed may cause a hard start. Important: The embossed arrows on the MAF sensor indicate the direction of the intake air flow. The arrows must point toward the engine. Install the MAF in the proper direction.

Check the camshaft position (CMP) sensor for proper mounting and/or a bad connection. A long crank time occurs if the PCM does not receive a CMP signal.

Check the fuel pump relay operation. The fuel pump should turn ON for 2 seconds when you turn ON the ignition

A faulty in-tank fuel pump check valve allows the fuel in the lines to drain back to the tank after the engine stops

Check both injector fuses for being open. An open injector fuse causes four injectors and four ignition coils not to operate. Replace the fuse. Inspect the injector circuits and the ignition coil circuits for an intermittent short to ground.

Check for incorrect fuel pressure

Check both injector fuses for being open. An open injector fuse causes four ignition coils and four injectors not to operate. Replace the fuse. Inspect the ignition coil circuits and the injector circuits for an intermittent short to ground.

Check for proper ignition voltage output with J 26792 Spark Tester

Remove the spark plugs and check for the following:

Correct heat range

Wet plugs

Cracks

Wear

Improper gap

Burned electrodes

Heavy deposits

Excessive oil in combustion chamber--Leaking valve seals. Refer to Oil Consumption Diagnosis in Engine Mechanical.

Low cylinder compression--Refer to Engine Compression Test in Engine Mechanical.

Combustion chambers for excessive carbon buildup. Clean the chambers using top engine cleaner. Follow the instructions on the can.

For incorrect basic engine parts. Inspect the following:

Cylinder heads

Camshaft

Pistons, etc.

Tweeter400 · October 22, 2003

Well, I have a little more info. My truck will start fine if I turn the key a few times to charge the fuel lines. It appears I am losing pressure when the truck sits for more than about 10min.

Thanks!

SportyShorty · October 22, 2003

Could it be the valve on the passenger side fuel rail that relieves the pressure in the fuel lines. Your pressure might be escaping through there but if you turn the key on and off, it builds up enough pressure for it not to matter. Who knows just another idea.