||11-20-2012 04:04 PM
Originally Posted by jschildm
If its glow plugs it will start hard, but once it is started, run just fine. If it starts and still runs like chit for an extended period of time, then there is something else wrong. Cam Position Sensor is a weak spot on them. If you have someone with a scan gauge or auto enginuity, then you could do a buzz test and contribution test on the injectors to see if they could be the issue. Some more info on exactly what it is (or isnt) doing would help.
If it idles OK, but absolutely won't get out of its own way, then you might check that the EBPV didnt get stuck closed.
Yes a cold glow plug will do that, then the cylinder is flooded and takes it a little bit to start firing properly. A failed glow plug won't ever ignite, which cuases the same symptom to be perminate.
Yes, run a tech 2 or similar device on it if you have it or know someone with it. If not time to visit a service shop. They can check your balance rates on your injectors and make sure they are all firing properly. Normally if an injector fails you'll have more symptoms than just missing. It will white smoke (even at idle), have fuel in your oil, knock like crazy... Might not be all of these but at least 1. Normally injector issues, it will still run and move around okay, just smoke and knock like crazy.
Those 2 things are going to be your most likely cuases... beyond that you are looking at possible turbo issues (i believe the 7.3 is a wastegate setup), valve issues (such as breather valves, bypass valves), Position sensors like jschilm said, ecm/wiring issues.
Sadly I blew my turbo on my 08 LMM Duramax yesterday... I'll spend the weekend rebuilding it... ohh fun Thanksgiving for me. lol