Hey guys/gals. I have been having this issue that comes and goes, mostly under very low throttle or idling. The RPM’s will barley move up maybe 200 rpms very briefly. My fuel pressure stays steady at 17 PSI. The below video is what I am speaking of. As you can see, and this is the first time this has happened, the check engine light came on. My dad has a scanner I can plug in to read the code, however any ideas at what might be the possible issue. Thanks. 

[video]

 

I also just noticed my temp gauge surges as well and then drops to zero after watching the video. 

Edited March 23, 20187 yr by Red Rambler

Get the code reader and see what the codes are. 

Being a 2001, you maybe able to do the key trick to read the codes without a scanner.

Yes codes first, but at idle with no TPS input ECM is in charge of that. Maybe cam sensor maybe something else, I would definitely check for excessive AC noise.

1 hour ago, Dieselfuture said:

Yes codes first, but at idle with no TPS input ECM is in charge of that. Maybe cam sensor maybe something else, I would definitely check for excessive AC noise.

Thanks DF. I will have the chance to get the code reader this weekend. I drove my truck this AM and no issues as shown above. I am going to read up on the process for checking for excessive AC noise. There are some good threads on this topic. My check engine light is still on, and did not go out on the way to work, only 20 miles though.

9 hours ago, Alexio Auditore said:

Being a 2001, you maybe able to do the key trick to read the codes without a scanner.

Thanks Alexio, I might give this a shot, see if it works.

2 hours ago, Dieselfuture said:

Yes codes first, but at idle with no TPS input ECM is in charge of that. Maybe cam sensor maybe something else, I would definitely check for excessive AC noise.

 

Exactly. As long as the APPS is at idle position then the ECM is direct control of idle speed. APPS sensor is not the cause. We do need the error codes use OBDII code reader most 2001 will only report PCM codes and then stop on the key trick. 

53 minutes ago, Mopar1973Man said:

 

Exactly. As long as the APPS is at idle position then the ECM is direct control of idle speed. APPS sensor is not the cause. We do need the error codes use OBDII code reader most 2001 will only report PCM codes and then stop on the key trick. 

Thanks, I will attempt to get these codes tonight, and report back.

My check engine light has now went off and the problem has not reared its head again. I will still check the codes and report back.

I have yet to pull any codes. I was able to test the alternator today, however the number is all over the place. It kept saying open loop when I tried to increase the range on my multimeter.

 

The key on/off trick worked on my truck, below are the codes:

PCU:

1693-DETECTED IN COMPANION MODULE (Given this code showed up, should I expect to see other codes while using the OBII scan tool?)

ECU:

0118-ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE TOO HIGH

0177-WATER IN FUEL

Edited April 3, 20187 yr by Red Rambler

https://mopar1973man.com/cummins/articles.html/24-valve-2nd-generation_50/51_engine/obdii-error-codes_94/

So does the below code tell me I need to use the OBD II tool to scan? I guess I am confused if I am seeing all of the error codes by doing the key trick.

 

1693-DETECTED IN COMPANION MODULE:

Mopar's Note's:

This error code cannot exist by itself and will have other error codes present in the ECM and/or PCM you'll most likely require a OBD II scan tool to get the codes.

Anybody have any suggestions for next steps in trouble shooting? My next step otherwise would be to purchase a new nations alternator. Also will unplugging my grid heater for the time being. 

It's weird how sporadic the numbers are on your alternator test. If it's truly like that, it seems the alternator is bad.

 

The 1693 code will always show when another code is thrown, but its telling you there are other codes. 

 

So the two codes, have you looked into those yet? 

 

 

1 hour ago, Red Rambler said:

Also will unplugging my grid heater for the time being. 

It will help, but if damage is done you need alternator, maybe verify with a different multimeter to be sure.

56 minutes ago, Alexio Auditore said:

It's weird how sporadic the numbers are on your alternator test. If it's truly like that, it seems the alternator is bad.

 

The 1693 code will always show when another code is thrown, but its telling you there are other codes. 

 

So the two codes, have you looked into those yet? 

 

 

The water in fuel code I can only assume is correct, could have been previous owner. 

The code for engine coolant temp is from installing my high idle switch. I didn’t have it hooked up right and started my truck. 

I am not seeing any codes that are life threatening. So that leads me to the high spikes in AC noise that could be causing the issue. 

12 minutes ago, Dieselfuture said:

It will help, but if damage is done you need alternator, maybe verify with a different multimeter to be sure.

I can check again tomrrow with an alternate multimeter and will recheck with the same multimeter. I just don’t want to be chasing an ecm and lift pump due to a faulty alternator. However my question is in regards to the nations alternator, I see it’s made in the USA which is good, and it appears that all others who have went this route have had success using the nations alternator.  But does it control the AC noise that much better? W-T seems to have figured out a solution for the grounding issues. I need to read up on that and go ahead and fix those while I’m at it. 

I would just put new alternator on and test that if your meter is still all over the place then I would be looking at the different meter

Did you have all accessories turned off and engine warmed up before testing?

Edited April 4, 20187 yr by Royal Squire

Typically the AC scale is in the 10 to 40 mV AC range. Be aware the meter has to be able to handle varying frequency. In other words, a lot of cheaper meters are designed for household 60 Hz 120, 240, 480 and up voltages. To find a meter that can measure mV range AC and any frequency it's a hard trick. That might explain some of the wandering. Because the ripple pattern is not a smooth pattern is a very random and choppy pattern the meter has to be able to work with that. 

51 minutes ago, Royal Squire said:

Did you have all accessories turned off and engine warmed up before testing?

Yes, truck was warm, and all accessories were turned off.

46 minutes ago, Mopar1973Man said:

Typically the AC scale is in the 10 to 40 mV AC range. Be aware the meter has to be able to handle varying frequency. In other words, a lot of cheaper meters are designed for household 60 Hz 120, 240, 480 and up voltages. To find a meter that can measure mV range AC and any frequency it's a hard trick. That might explain some of the wandering. Because the ripple pattern is not a smooth pattern is a very random and choppy pattern the meter has to be able to work with that. 

Here is the info on my multi meter.

 

Bingo... Frequency range is only 50 to 60 Hz.