Help I need some information on what to do with my 2000 dodge ram 2500 5.9L gas job it starts idling rough and almost sounds like it'll stall after about 5 minutes of running but only for about a minute then it straightens out and runs smooth after that but during that time it brings up a p1391 intermittent loss of cmp cmk . I've replaced the cam sensor cap and rotor wires and plugs recently cleaned the throttle body and iac I do have a plenum gasket leak which I haven't fixed yet any help would be greatly appreciated thanks.

 

Were you getting the code before you replaced the cam sensor?

 

Yes it did Hey You if I remember correctly
but it went away for awhile after changing the cam sensor

 

Disconnect the front O2 sensor, and see if anything changes.

 

Ok I was kinda thinking about doing that already I'll try that tomorrow since I already had it running today and it seems like it has to sit for several hours before I can get it to do it again. Thanks Hey You I'll try that and comment back on the result of that test.

 

Well that didn't make any difference, what do you think I should try next coolant temp sensor and what sensor's start reading when it goes into closed loop?

 

It *should* start paying attention to the O2 sensors after two to three minutes running. Heated O2 sensors are a wonderful thing. After five minutes, I would expect the engine isn't quite fully warmed up yet, and I wonder if the issue doesn't roughly coincide with the thermostat opening the first time....... It may be temp related, but, I suspect the only way to verify that is the case, would be to do some data logging. If you don't have the capability for that, the temp sensor would be a pretty good guess. (and that's all it would be.... a guess.....) Only one temp sensor on yours, so, at least it should be easy to find.

 

Well I tried unplugging the temp sensor but still same result it did throw a code for it though when I had it unplugged and it also had one from the o2 from the day before which didn't throw the check engine light but came up when the temp sensor was unplugged I tried another thing though unplugging the iac right after I started it cold and also again when it started to get temperature and also gave it some good revs 2500 to 3000 rpm with it unplugged no change in idle not even a check engine light. Is this normal

 

The PCM should figure out the IAC isn't working in fairly short order..... and whine about it. I don't know exactly how long though...... Should set a P0505 code. May wanna check and see if that one is pending. (need a scanner.)

 

Ok thanks for the info I'm gonna order a new one anyway as well as a crank sensor and see what happens from there thanks for the help and have a good one Hey You