Surging When Cold

[jlwelding]

It surges when eng is cold and after it warms up it seems fine. It reminds me of a tank half full of water, you feel the push then it drags back. I just installed new vp44, new injectors, crossover tube o rings, new airdog 165. Talked with Lenny at DAP and he suggested hooking up Iquad and see what datta it might show. I havent installed the Quadzilla Iquad yet because of this. I also just reset my apps a few minutes ago to see what happens in the morning. A real head scratcher, I hear about ecm's doing this but its always when it heats up, or the vp doing this as it heats up. This gets better as it heats up.

[LorenS]

I don't have any ideas on this, but really like the diagnostics/detective threads so will be following along!

 

Being able to see what the computer is being told by sensors may be critical to solving this one. Do you have a relatively good OBD reader like an OBDLink LX or MX? Or hook up the Adrenaline to see live data.  Before starting engine see if anything looks weird, like coolant, fuel, or intake air temperatures.

[jlwelding]

So would injectors cause this? I have the DAP 50hp injectors and they are pretty smokey, just shifting normal they blow pretty good amount of black smoke at first then clean up. They were not as smokey at first as they are now. Also they have a heavy lope to them especially when backing up. Would a torn O ring cause this, or cross over tubes? No codes that I can bring up with the ignition.

[Me78569]

yes they could.  loping and smoke point to a pop pressure that is failing below the typical levels.

[Mopar1973Man]

Low pop pressures typically get smokey. Still running my 7 x 0.010 150 HP injectors popped at 320 bar are still clean burning. I've even tweaked my tune and lowered my oil temperature back to 163°F and 195°F coolant with 100°F outside temperature and lowered my EGTs again. Increased my MPGs again. Still running the stock HX35W turbo.

Edited July 16, 2022 by Mopar1973Man

[jlwelding]

Installed new 50hp injectors again , going to send the other backs. Dap said they would check them and get back to me. Mean while I got a buddy to hook his scanner to it and check for codes, course I did grid heater delete and those two codes came up but nothing else. We checked the vp44 and the vp rpms were wild jumping around from 2025 to 1500 and as low as 10, Im thinking if its not in the vp then maybe the ecm. Who is the go to guy to check the ecm?
The VP44 is new through DAP I guess I'll get with them and see what they think.

Edited August 13, 2022 by jlwelding

[LorenS]

19 minutes ago, jlwelding said:

Who is the go to guy to check the ecm?

@Auto Computer Specialist is who you want to contact.

[Mopar1973Man]