Trouble Starting

whiplash · May 10, 2008

Hey guys. I have an '05 GMC Sierra with a 6.0 engine and 11000 miles. Lately I have had problems with it starting. If I turn the key to start it I can release the key and it will continue to turn over for 5-10 seconds. It will eventually crank (while cold) and then drive normal. If I drive it and get it up to operating temp. then shut it off for like 10-20 minutes then try to restart it it takes 10-15 minutes for it to light off! I did search before posting and read about the fuel regulator and pump issues and I haven't done any troubleshooting yet but with only 11000 miles and with the starter remaining engaged I thought that might not be the issue, but I could be wrong. Any help is greatly appreciated!!

cammiller · May 10, 2008

The starter remaining engaged is normal. The key is only an input to the PCM. When the key is in the crank position for more than 0.4 second, the PCM starts a crank timer which continues to crank for 10 seconds or until the engine starts. I'll look into the other part in a bit.

whiplash · May 11, 2008

The starter remaining engaged is normal. The key is only an input to the PCM. When the key is in the crank position for more than 0.4 second, the PCM starts a crank timer which continues to crank for 10 seconds or until the engine starts. I'll look into the other part in a bit.

Thanks for the reply BlueGorilla. I had a little time to look it over today and I bought a universal fuel pressure tester but none of the adapters would work for me. It appears the fuel pressure port on the truck is M12x1.5 and my hose to mate the gauge to the port was 7/16-20. I am going to look for the right hose tomorrow time permitting. The truck only has 11000 miles on it but it is surely possible that the regulator or pump is the culprit. Thanks again for your help!

cammiller · May 11, 2008

It certainly is a good place to start. Is the Check Engine light on? Can you hear the fuel pump running? Keep in mind the pump, regulator and filter are one unit on there trucks. Pressure should be 55-62 psi while the pump is running. What is your e-mail?

whiplash · May 11, 2008

It certainly is a good place to start. Is the Check Engine light on? Can you hear the fuel pump running? Keep in mind the pump, regulator and filter are one unit on there trucks. Pressure should be 55-62 psi while the pump is running. What is your e-mail?

I might have been at the wrong location. I have not been able to find a service manual locally. I was attempting to connect to the port at the front of the manifold on top facing forward with the green screw-on cap installed from the factory. I always thought the regulator was separate, so I have my work cut out for me!! I do hear the pump running by the way. So everything is in the tank or close by it? Also, no codes or other problems. PM sent by the way. Thanks again for all your help!!