I have a 2001 Dodge Ram 3500 5.9 cummings truck. The feed pump (low pressure) was replaced 1 1/2 years ago. It starts rough but runs fine until it warms up. After it's warmed up it will only run at an idle or 1400 rpms. I've changed the fuel filter & it didn't make any difference. I also get the code P1693. Would it be worth the money to take it in & have it checked on the mechanics computer? Anyone have any ideas on what's going on?
Any help or advice would be great!
Thanks,
Welsch

 

1693 = DTC Detected In ECM Or PCM. This could be good as it's saying either the Engine Control Module or the Powertrain Control Module has a code stored in it. You will need a code reader to get it but it should point you at your trouble.

 

Code readers have really come down in price to the point where we can just about all afford one. I'm sure one trip to the dealer would buy a code reader. On another note if you don't have a fuel pressure gauge yet you should install one.

 

My money is on the injection pump being toast. Once the delivery valve housing erodes enough, they run rough at low RPM following start-up, and then have no power when warm. Eventually, it will just quit.

If your previous low fuel pressure was during hot weather, then you can bet the injection pump is gone. The flow of excess diesel through that pump is the only form of cooling and lubrication it has, interrupt that and the pump will be seriously damaged.

 

Most parts houses (autozone,etc.) will check codes for free

 

i got one from checker auto for 70 dollars