2001 24v Cummins High Idle Issue

[Mopar1973Man]

53 minutes ago, DanTheMan said:

Thank you for the info, I’m going to use a piece of electrical 4x4 box blank stainless plate and cut it to size and use a cork gasket behind it. I wonder why there is a hole there if it’s meant to have the lift pump mount there..

12V series block had a mechanical lift pump rode on the cam lobe.  24V they used a L shaped bracket to mount the lift pump from those bolt holes. So it was dual purpose block off plate and a mount for the electric pump. Sadly, some dummy pulled the plate and used cardboard and silicone to keep the oil from running out.

 

Part #1 - You can see the bracket and how it held the stock lift pump.

 

53 minutes ago, DanTheMan said:

I am seriously at a loss here, I’m probably going to pull the entire front end apart and really get down in there to check every inch of this harness, and really look at all connections and rewrap etc. 

Auto Computer Specialists can do harness rebuilding too.

 

https://mopar1973man.com/vendor.htm/vendor/auto-computer-specialist-r5/?do=getLastComment&d=7&id=5

 

53 minutes ago, DanTheMan said:

I am now doubting ECU because it idles what seems like normal for a few seconds occasionally after unplugging and plugging in the ECM to PCM harness, I’m wondering if there’s something going on inside those connectors now.

Dielectric grease will seal water and road salts out keeping the contacts clean and functional. Use some contact cleaner then use the dielectric grease.

 

Forward...

 

Just consider I've managed to build a 492k mile truck up to about 500 HP now, 30+ MPG and enough power to tow, drag, or just haul. Once you get the other stuff fixed then we can start optimizing the rest of the truck. 

 

https://www.tiktok.com/t/ZTF3eREgC/  <- Beast out in the snow a year or so ago.

Edited November 6 by Mopar1973Man

[Great work!]

Check the PCM ground to the passenger battery. The PCM is not grounded by it's case.

Have you done the blow-by test with the oil cap yet. if it bounces around while setting over the hole you have bigger issues. 

[DanTheMan]

@Mopar1973Man Thank you sir for the information. You rock. Nice truck, I followed you on TikTok.

 

@Great work! I’ll check the ground, thank you. And also, yes the blowby is zero. Although it could be (if it has blowby) blowing out of the hole where the lift pump used to be that someone sealed off with cardboard… Once I get it sealed off, I’ll check again.