HELP... 24 Valve rough idle when hot

[SSIRMAN]

Okay so i bought this truck and drove it with no problems except for having to rebuild the weak auto trans , but i was driving it for about 15 minutes and got it good and hot then i stopped at a store and when i came back outside to leave, when i started my truck back up the engine started revving uncontrollably up and down like i was stomping on the pedal really fast on and off. I turned it off and caught a ride from somebody else and when i came back later, it started up just fine and i drove it home. Ever since, this has happened maybe 4 times and once it happened while i was driving. I got to a red light and the truck shut off, when i tried to start it back up same thing happened. Ive always had a weird idle where it kind of sound like an intermittent miss, but now it seems more severe. Even when i rev the engine and hold it at a higher rpm i can still feel it missing intermittently. I checked the codes and i got P1690 and P0341. I have replaced the cam sensor, checked all the wiring between the TPS and ECM and the CPS and ECM. Since this started i have tried multiple repairs like replace the lift pump and injectors because of info found on other forums. I sure hope it isnt the VP44 or the cam reluctor wheel. What do y'all think? Any help would be appreciated

Edited September 30, 2018 by SSIRMAN

[Mopar1973Man]

Test your alternator for excessive AC noise. 

 

Miss at hot idle is typically a sign of worn out injectors and the pop pressure is really low and the injectors are getting pissy.

 

 

[SSIRMAN]

1 minute ago, Mopar1973Man said:

Test your alternator for excessive AC noise. 

 

Miss at hot idle is typically a sign of worn out injectors and the pop pressure is really low and the injectors are getting pissy.

 

 

I replaced my injectors and the problem didnt go away, its exactly the same

[Mopar1973Man]

Just now, SSIRMAN said:

I replaced my injectors and the problem didnt go away, its exactly the same

 

Ok. Did you tighten the injectors in the right order?

 

Crossover tube seat it lightly. Torque the Injector hold down caps to 89inch/pounds. The finalize the crossover tubes.  

[SSIRMAN]

3 minutes ago, Mopar1973Man said:

 

Ok. Did you tighten the injectors in the right order?

 

Crossover tube seat it lightly. Torque the Injector hold down caps to 89inch/pounds. The finalize the crossover tubes.  

Yes i put in the injectors in and then inserted the crossover tubes and made sure they seated all the way in, then i torqued the injector hold downs

[Mopar1973Man]

Ok so the injectors are covered. That leads me back to be sure the power and sensors are not getting AC noise. 

 

 

[SSIRMAN]

30 minutes ago, Mopar1973Man said:

Ok so the injectors are covered. That leads me back to be sure the power and sensors are not getting AC noise. 

 

 

alright i drove my truck, got it up to temp and turned off all my accesories and measured .040 volts AC

[Mopar1973Man]

Might get it to the stag of missing then test again. I'm wondering if a diode is failing when it's getting hot and creating the issue? Keep an eye on it and see what happens. As for something that might just buy time for that current alternator in the W-T ground wire mod. 

 

As you'll see the ECM, VP44 and other sensors have the alternator noise running past the master ground for everything. Black/Tan is the master ground from the passenger battery and the solid black is the alternator charge lead. 

[Dieselfuture]

After you make sure you have no excessive AC noise and do ground mod and still have problems it could be your PSG on vp44 or ecm from being damaged by AC current. When you not touching go pedal ECM is in control of idle. You can also try dumping cold water over vp44 computer PSG when it acts up and see if it gets better. Sometimes there is no code for VP or ECM. 

[cumminsdog]

check for air in your fuel system.

[SSIRMAN]

Thanks mopar1973man, i replaced the alternator and did the ground wire mod. Been driving it for a few days with no problems so far