Engine/Transmission (1998.5 - 2002) The cummins has a little rev up after start

[silverram323]

I have noticed my engine has a little rev up after start. It has been doing it for a while and I figured it would go away but it didn't. It only does it once in a while, no rhyme or reason. Do any of you guys have or fixed this problem? All mods are in Sig

thanks kevin

 

[Sticks]

Does it do it right when she fires up, or after a little bit of idling?



Only once, or intermittently during idle?

 

[JohnMcIntyre]

APPS on the wayout....

Your sig file does not say how many miles you've racked up..... However you must be up around 60k miles I guess. Run a search on the TDR website with the keyword APPS. This stands for Accelerator Pedal Position Sensor. You could be experiencing the early stages of an APPS failure, when your "go-pedal" starts to exert a mind/control all of it's own..... Keep your brake pedal covered ... . just in case it gets worse/larger.



The APPS sensor is under the hood up front, between the block and the radiator assembly. Check the details in your service manual (good value at $120 last time I checked). a quick clean out will save you the best part of $400 for a replacement unit if it is on the way out..... and give you another 60k miles... .

 

[Sticks]

John - He has a newer one. $350ish from Cummins or another big rig shop. NOT SERVICABLE! Damn DC!



Autopsy of an APPS

 

[JohnMcIntyre]

non-serviceable APPS unit?

Sticks,

So does that mean upto and including the 2001 model year only are serviceable then?

What did DC do for 2001. 5 onwards?

If it's on the way out, can you replace a faulty 2001. 5 unit with a (serviceable) 2001 unit instead?



JMc

 

[silverram323]

Its kind of a flare up right after start up. I checked for intake leaks but found none.

 

[Sticks]

Re: non-serviceable APPS unit?

Originally posted by JohnMcIntyre

Sticks,

So does that mean upto and including the 2001 model year only are serviceable then?

What did DC do for 2001. 5 onwards?

If it's on the way out, can you replace a faulty 2001. 5 unit with a (serviceable) 2001 unit instead?



JMc

I don't know what year they went to the new style, it might be 98. 5 with the 24v change over. I do know that the old ones were a three wire plug that you could open up the unit and clean it up. The newer ones are a 6 wire plug that you can't clean what needs to be cleaned (yet).

 

[Bodybomber]

Mine is doing the same thing AGAIN. Had the problem before. Would do it once then nothing for a couple weeks then 3 times in one day. Took to dealer less the Comp and as usual they said "never heard of that". Somehow they determined they needed to reflash. Its been ok for 4 months now but did it twice yesterday. I was talking to someone else who had the same problem. He also had a Comp but wasnt tapped. Maybe loose conection someplace?? Im going to check mine today.

 

[Jack in Alaska]

Mine does the same but randomly and not very often. How do you find that problem???? I am still working on the "whooing sound" problem at start-up.

 

[Intelman34]

Mine has just started this. It seems to start with a very quick rev up and then all is fine. It only does it about once out of every 5 startups.

 

[Jetson]

Mine was doing that. I thought I had accidently laid my foot on the pedal when I cranked it. Two months later the VP44 went out. I changed the pump and it did it a few more times the next week or two then it stopped. It starts normally now.