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

I put a new ECT sensor on, ran my truck, it ran fine. I logged live data on it and will see tomorrow if I had any temp drops like previously. I than installed the Timbo APPS and ran my truck again, logging the live data on this run as well. Just need to throw my data in excel. I was running down all of my wires and did notice one thing, where my high idle switch wiring harness passes through my firewall that a damn mouse had been chewing on the wires. I taped those up and put wire loom around all my wires passing through the firewall. Upon this I discovered also that the heat/noise liner on my firewall had mouse crap on it, so I proceeded to rip that all off my firewall. I am not sure if this could have been my issue all along but I know when I plug my truck in that a mouse would find under my hood nice and toasty on a super cold winter night. I might need to put my truck on a timer versus plugging it in all night in the future. 

 

One question I do have is when you switch over to MPG mode on the high idle switch, does everybody get a short rev? Mine has always done this, I assume that’s the adjustment in timing? 

Edited April 27, 20186 yr by Red Rambler

With temps at 20* it only takes 30 to 40 minutes to bring the block up to 60* for an easy start. No need for it to be on all night. I use a timer on mine.

10 hours ago, Red Rambler said:

One question I do have is when you switch over to MPG mode on the high idle switch, does everybody get a short rev? Mine has always done this, I assume that’s the adjustment in timing?

 

No. Normal operation for me. You might look at the live data for the ECT and IAT temperatures.

1 hour ago, dripley said:

With temps at 20* it only takes 30 to 40 minutes to bring the block up to 60* for an easy start. No need for it to be on all night. I use a timer on mine.

Which timer do you have, I do have a timer, but if the power goes out it has to be reset.

1 hour ago, Mopar1973Man said:

 

No. Normal operation for me. You might look at the live data for the ECT and IAT temperatures.

Will do, I have been logging ECT, but not IAT. I have not had any weird revs at idle but looking at my ECT numbers, it still drops out and I have even seen (-27). Still could be an ECM issue. I am getting a slight rev under throttle, its similar to when you put the cruise control on and the computer takes over, however this is when I am using my pedal to throttle. What could make the throttle increase while under throttle already?

Edited April 27, 20186 yr by Red Rambler

5 minutes ago, Red Rambler said:

Which timer do you have, I do have a timer, but if the power goes out it has to be reset.

 

Something like this...

https://www.homedepot.com/p/Westek-Heavy-Duty-Outdoor-Timer-Black-TM12DOLB/100645892

1 minute ago, Mopar1973Man said:

 

Something like this...

https://www.homedepot.com/p/Westek-Heavy-Duty-Outdoor-Timer-Black-TM12DOLB/100645892

Yeah, that looks much better with mechanical timer, versus my current digital one.

1 hour ago, Red Rambler said:

Yeah, that looks much better with mechanical timer, versus my current digital one.

Mine is similar just without the cord. The timer just plugs in the. Mine is NOT weather proof.

22 hours ago, Red Rambler said:

I am getting a slight rev under throttle, its similar to when you put the cruise control on and the computer takes over, however this is when I am using my pedal to throttle. What could make the throttle increase while under throttle already?

 

The only thing I can think of is a sudden timing shift. As timing advances it produces an increase of throttle. 

2 hours ago, Mopar1973Man said:

 

The only thing I can think of is a sudden timing shift. As timing advances it produces an increase of throttle. 

I’m pretty sure you nailed it and the issue is my high idle switch which the damn mouse had chewed on. The wires were exposed where it passed through the fire wall. I have unhooked my idle switch and it has ran perfect. I have to do a few wire repairs but it was chewing on my main harness going through my firewall. It got chewed the tape off. 

We do have replacement cables in the store.

 

30 minutes ago, Mopar1973Man said:

We do have replacement cables in the store.

 

I am going to pull it today, I’ll be in touch for sure either way. I am hoping it is just the casing that got chewed off. 

Contact info at the bottom of the page. 

I got all of my issues resolved finally. On my high idle switch the wires that were chewed on were the LED light wires, so I just taped those up and the rest of the harness is untouched. The issue I believe was where there were bare wires showing on the main harness going through the firewall. All is well now I’m very happy to report. I hauled a load today and it pulled like a champ. I used heat shrink and electrical tape to fix the damaged wire, it was only 1 wire thankfully. I also went to Home Depot and got some mice repellent. They are little peppermint pouches that tie. I tied two under hood. Does anybody have any tried and true mice repellent tactics? Thanks for all the help on this also, great forum to be a part of. 

Edited April 29, 20186 yr by Red Rambler

Only tried and true method I’m aware of is to capture them!

14 hours ago, Royal Squire said:

Only tried and true method I’m aware of is to capture them!

Thanks Royal. I purchased the peppermint scented bags from Home Depot and also set 3 traps under hood. They were all empty this AM. The bags last about a month and then you have to change them out. The mice thing is new to me. I have never had issues in the past. 

 

Sorry not my truck or cat, but my cats do help a lot.

Try not to park the truck in the same place every night.  Rodents remember where food and a warm place to nest is and will keep coming back to the same place. 

On 4/3/2018 at 3:39 PM, Red Rambler said:

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.

 

Basically, if the P1693 is reported from the ECM that means there are codes in the PCM. If the P1693 is reported from the PCM than means there are more codes in the ECM. If reporting from both PCM and ECM then both modules at pointing at each other to having more codes. That's all it means nothing more. 

I logged my live data again this AM, and zero temp drops, ECT, IAT, and RPM's are all steady. I will start alternating where I park my truck, but since I have put the Peppermint bags under my hood I am not seeing any signs. This will become a monthly regimen of mine, to put new bags under my hood. Thanks for all the help