2009 6.7 Cummins 3500, having a heck of a time trying to figure out what is wrong. Intermittently while driving it shuts off and back on again, at idle shuts completely off, no engine codes thrown. Instruments go dead then come back to life, no electrical issues, radio and windshield wipers don't miss a beat. I read how to check the FCA by taking it off and spraying it with wd 40, if the problem goes away replace the part...it went away and I replaced the part...this is not a good way to test this lol. As soon as I put the new one in it immediately started bucking again. Checked the fuel pressure between the filter and injector pump while key is on and it registered 15 PSI. Figured it might the pump. just about got the bed off and something is nagging at me to check with someone. What should my pressure readings be? I'm running chipped with the Edge. I unplugged it and no change. Any help is appreciated.

 

Have you load tested your batteries? When were they last replaced?

 

The batteries are a little over a year old and I've checked the connections

 

Depending on what is going on, the batteries could still be problematic. Should probably load test them (disconnected) to rule them out. Otherwise, might be some other electrical connection (besides to the batteries themselves). I am not a fan of the Edge chip set-up.

You're not getting any codes or lights? Even if not, you should do a deep scan of the ECN for anything.

 

Thanks, I will certainly check it out, I got truck apart right now putting in a new fuel pump. Once I get it back together I'll take it down to a battery shop or garage.

 

Pick yourself up a cheap load tester from harbor freight or something like that. Very useful to have around. Did you find anything wrong with your previous lift pump? I thought you said the PSI was good?

 

My lift pump is in the gas tank with the fuel pump, I will pick up a load tester tomorrow when I go down there and give it a whirl. Sounds like it couldn't hurt to have one around. Thanks.

 

If im not mistaken I believe the 6.7 had an issue with the injector harness under the valve cover causing it to cut out. May be worth looking into.

 

If it continues after the new pump is in I'll check it out. I don't have a check engine light and no codes were thrown. It would certainly be a lot easier than taking the pump out of the tank lol Thank you.