Persistent missing

Ghostman

Ghostman

24v crazy
Joined
Aug 24, 2012
Messages
2,819
This truck is having a persistent but random miss and/or sputter. Like it drops a cylinder randomly. Here is the background:

2002 cummins 2wd:

- westons injectors
- edge ez
- super B
- intake and exhaust
-FASS filter and pump
-gauges

That's about the extent of the performance mods. The vp44 is from DAP I think and is only about 2-3 years old tops and maybe 20k miles. Truck runs great when it doesn't miss. Hauls the grass if you know what I mean. I have not gotten any VP codes lately.

It seemed we had a rash of sensors go out at once; rear diff sensor, and cam sensor. We also had the alternator checked and it was bad and was rebuilt by a shop that is very familiar with the alternator problems and a/c voltage issues that can occur with these trucks so it should be good now.

We've tried disconnecting the edge and it makes no difference if the truck misses or not. I'm thinking maybe its ecm related? Any thoughts?
:nail:
 
If it's random cylinders I'd swap the ecm. That's where I'd start after the stupid simple stuff.
 
Is it at idle or while driving? If it is with any throttle input I would look into the ecm.
 
jlbayes said:
Is it at idle or while driving? If it is with any throttle input I would look into the ecm.
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E. all of the above. We've also changed our the apps as well


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Checked valve adjustments lately?

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Ghostman said:
hot wire the pump? Never heard of that?
Click to expand...

HOT WIRE TEST - THE "FOR SURE TEST" TO DETERMINE IF THE VP44 IS WHY THE ENGINE WON'T START
It is very rare, but possible, for a problem with the wiring harness or the CAN Bus wires to prevent the engine from starting, so if you want to be 100% sure it IS the Injection Pump causing the no start, follow the following directions exactly, to be sure of not damaging a possibly good pump. This test POSITIVELY eliminates the possibility of overlooking an electrical problem caused by other components that could affect the start or run function of the VP44, as long as you have verified fuel delivery to the Injection Pump. Remove the electrical plug at the back of the Injection Pump and hot wire the pins on the pump as follows. Get two wires long enough to reach from the battery to the VP44. Install an INSULATED ¼ inch female spade connector onto one end of each wire.Use a set of dykes and cut the flat part and one of the "curls" away from each spade connector to leave one "curl" , which will be about the right size to go over the pin on the pump. Connect one INSULATED connector to pin 7 on the pump, which is the pin on the BOTTOM row of the socket on the Injection Pump, closest to the engine, to preferably fused (10 amp is fine) positive battery power in the PDC (Fuse box under the hood), or directly to the positive battery terminal if you like to take risks!.
Connect the other INSULATED connector to the pin directly above the previous connection, the top row of pins, the one closest to the engine, and attach the other end to battery ground. Now try to start the engine and if it doesn’t start, you absolutely positively 100% need an Injection Pump! If the engine starts this way but NOT with the big plug installed on the pump, you know there is something in the harness or CAN bus wiring to the ECM telling or causing the engine to not start. Call me for help if this is the case.

BRE said:
I've had one that only had issues at idle...

Crappy video, but this is what it would do. https://vimeo.com/187868830
Click to expand...

I'll have to watch this off another computer with no restrictions.
 
I know this may sound far out, but I think it's fixed. The alternator was pretty bad I I'm blaming all this on it. After driving about 2 days after putting on the good alternator is hasn't missed since and it's even driving better it seems and shifts better it seems. Could the A/C voltage have caused all this? It sure seems like it might have.


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The xecessive AC sine waves could have been causing interference...the issues is, for how long ?

There could still be damage to the ecm amongst other items...only time will tell.
 
Just gonna keep driving it for a while before I drop coin on a ecm.


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Had same thing before bad cell in battery and weak alternator would miss so bad it would almost stall if you shoved into it to fast
 
Did it miss in park and neutral only or even in gear under a load. Mine is missing when it gets warm unloaded only, trying to figure out what's wrong.
 
Jkidder85 said:
Did it miss in park and neutral only or even in gear under a load. Mine is missing when it gets warm unloaded only, trying to figure out what's wrong.
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Missed anytime, any circumstance. I would highly suggest checking and/or replacing alternator with a known good one.


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