Jump to content
  • Welcome To Mopar1973Man.Com LLC

    We are a privately owned support forum for the Dodge Ram Cummins Diesels. All information is free to read for everyone. To interact or ask questions you must have a subscription plan to enable all other features beyond reading. Please go over to the Subscription Page and pick out a plan that fits you best. At any time you wish to cancel the subscription please go back over to the Subscription Page and hit the Cancel button and your subscription will be stopped. All subscriptions are auto-renewing. 

1999 24 valve high idle and bucking at highway speeds


Recommended Posts

So I have a 1999 24 valve all stock no tuner.. and I can start the truck and it fired right up and it will idle around 800 or so rpm and when I hit the throttle it will idle at 1100 and at highway speeds the truck will buck and if I let off it’s fine until I get on the throttle again I just replaced tps/apps and set the correct voltage and done the pedal thing the map and iat sensor are showing they work on my scan tool but no codes I’ve only owned the truck for a couple weeks and the vp44 has a sticker on it and it looks brand new all my ground are good but idk what to do.....

Link to comment
Share on other sites

Yes it was doing it before so I bought another one from rock auto and it had no voltage to set it at so I found somewere the basic voltage and set it there and it did the same thing ig I learned my lesson buying cheap parts but my timbo should be here today 

Link to comment
Share on other sites

Didn't say Jack about setting any voltage on Timbo.

The phrase "There is no voltage to check" could lead people astray.

If your not checking voltage, why do you need a voltmeter?

So do you set the apps according to instructions or just set it OE? 3 or 1

Mine is just about 10 years old, & if the instructions are followed to a T, you win, IF that was the problem.

 

 

 

  • Like 2
Link to comment
Share on other sites

I tried measuring the voltage according to the instructions sent with my timbo and it did the same so I said well I’ll try it with true ballcrank screw all the way out and I did that and reset the apps and it doesn’t buck and hiccup now but it still idles high

Edited by 24vgarrett
Link to comment
Share on other sites

  • Owner

How old are the injectors? If the injectors are over 100k miles for sure they are shot. As injectors wear the pop pressure falls. The engine load will reach 0 and the ECM will not be able to defuel enough to get the idle down to 800 RPM. If the injectors are questionable I would have them sent for testing. 

 

Link to comment
Share on other sites

6 hours ago, Mopar1973Man said:

Voltage is only use to see if you cross the boundary from idle to throttling and then you unscrewing the stop pin till you come back to rest in the idle zone. 

I think that migt of been misleading to some that are doing this for a  first time. 

So if someone says no voltage measuring needed with timbo, but let's say when apps is installed and it's in voltage range where it's fueling, because idle screw was too far in, then it can be misleading saying no voltage adjustments needed.

Not even sure who said what or pointing fingers, this is what I got from reading some things in this post. 

A lot of us like to assume conclusions without facts and it leads us on wrong path.

Going back to my corner now :kick:

Link to comment
Share on other sites

I’m not sure how old my injectors are I haven’t owned the truck long but if I put my truck in gear and let out on the clutch it will idle down to 800 until I hit the throttle again I can start the truck and it idle at 800 and then hit the throttle it go to 1100 and then I can put a load on the engine and it idles down

Edited by 24vgarrett
Link to comment
Share on other sites

  • Owner

Ummm. That's too high period. ECM possibly has fueling table issues.  I was think lower like 850 to 875. 1100 RPM is like the 6 cylinder high idle but typically brake pedal or touching throttle cancels.

 

It should not be 1100 rpm at any point after touching the throttle.

 

I've got an guy in Texas I've been working with he's got 3 trucks with the same issue. I'll post anything I learn on this too.

Link to comment
Share on other sites

×
×
  • Create New...