halfshaft5
10-10-2005, 09:15 AM
I have a 95 tahoe with a 6.5 turbo. Just recently the motor will run fine and then just die. It will start back and do just fine or you have to wait a minute and then it will start. I have replaced the PMD but thought the injection pump was alright. Is the injection pump having problems. I have also replaced the fuel pump last week but it has done the same since. Only really only happens when I am in a hurry. If I stomp it it kind of sputters then goes so I am puzzled. This is my 6th gm diesel and I have had the experience that when the injection pump goes then it goes, it will just plain quit and not start back. Are the newer injection pumps retrofited with a limp home mode or what. I need this thing so if anyone has a solution then please help. Thanks for your time and God Bless.
Michael
guybb3
10-10-2005, 09:35 AM
OPS??? Have you checked your fuel pressure and delivery??
Goldsburg
10-10-2005, 09:36 AM
With the Jekyll and Hyde nature of the problem, it sounds like you are having problems getting adequate fuel (pressure) to the injection pump. This could be a fuel filter, an OPS switch, or an electric lift pump issue. You need to check out the diagnostic check list in the FAQ's. Answer all of those questions and you will most likely lead yourself to the answer!
6.5TD FAQ's are here: http://dieselplace.com/forum/showthread.php?t=42248
Diagnostic Checklist is here: http://dieselplace.com/forum/showthread.php?t=42248
If you would like more help, post the Diagnostic Checklist (with your results included) back in this thread.
Happy Hunting!
Juancho
10-10-2005, 01:19 PM
Goldburg is right on the money. Your OPS or lift pump is toast.
halfshaft5
10-11-2005, 09:41 AM
How do you test the OPS. That is the optical sensor in the injection pump right?
halfshaft5
10-11-2005, 09:42 AM
Forgot to post that I replaced the lift pump a few weeks ago and thought that was the culprit but turns out its not.....
w_huisman
10-11-2005, 10:01 AM
Check out the "STICKY" threads at the top of the 6.5 Forum. Step by step OPS diagnosis will be in one of those threads.
http://dieselplace.com/forum/forumdisplay.php?f=21
Steve93mustanglx
10-11-2005, 10:02 AM
How do you test the OPS. That is the optical sensor in the injection pump right?
No, the OPS is on the back of the engine against the firewall. Takes a 1 1/16" socket to remove. It provides power to the lift pump. Mine sent voltage to the pump, but no current. Replaced OPS and it worked.