Engine/Transmission (1998.5 - 2002) Intermittent loss of throttle response

[Billy Diesel]

I lost throttle reponse last weekend, so I unplugged the APB, and that didn't help. I then unplugged the VA, and my throttle response was back. So, for S&G's I plugged everything back in, and the truck ran like normal.



This weekend I went up north snowmobiling, and on the way back the same thing happened. I couldn't hold 60mph floored, with the APB cranked. So, I unplugged the VA, and that solved the problem for a couple miles, then it started acting up again.



I thought it might be the APPS, but using cruise control didn't solve the problem. Everything I have read indicates that you can bypass the APPS using cruise control, so the APPS is ruled out.



However, the goofy part is that if I rock the throttle back and forth a couple of times while it is acting up, the throttle response comes back.



No codes are set, so I am going to try some di-electric grease on the contacts for the VA over lunch and see if that helps.



Does anyone have any other ideas for what could be causing this?



TIA,

Will

 

[Billy Diesel]

Di-electric grease didn't help.



Boost will usually be around 0-5 psi when happening, and EGT's are low, indidcating a loss of fuel.



Instead of saying there are no codes, I should've said that I have 0500-VSS showing, but that has been there for almost a year. It came from driving when it was -50F. So, I don't think it is the problem. Any suggestions?

 

[justinp20012500]

I have the same thing when accelerating at about 1/2 throttle around 1700 to 1800 rpms. I replaced the MAP sensor and replaced the VP when i did the fire rings and I still can't get it to go away.

I unplugged the EZ and it was gone. I then called Edge to try to get a new one and they told me to "pound sand. " My EZ was 2 years and 2 months old. I was 2 months out of warrentee.

I then asked if I could get a little better price on a new unit then retail and again the pound sand attitude came out.

Good luck on the problem.


Justin-

 

[Straight6Jeff]

Same thing mine has done on two sets of occasions... both time it was the injection pump.

 

[Sick Boy]

I Have Same Problem Only When Startin Out I Have To Play W/ The Peddle To Make It Shift From 1st To 2nd. But Sometimes I Can Go A Week An Its Fine. I Think It Has To Be The Apps. Ive Rereplaced The Trans Speed Sensor An The Gov. Silonoid An That Was Not It. truck Has 58,000 Miles On It

 

[Billy Diesel]

Same thing mine has done on two sets of occasions... both time it was the injection pump.

Were any codes thrown?

 

[Billy Diesel]

I Have Same Problem Only When Startin Out I Have To Play W/ The Peddle To Make It Shift From 1st To 2nd. But Sometimes I Can Go A Week An Its Fine. I Think It Has To Be The Apps. Ive Rereplaced The Trans Speed Sensor An The Gov. Silonoid An That Was Not It. truck Has 58,000 Miles On It

From what I have read, the manual transmission guys that had the APPS go out on them, they can accelerate via cruise control, because the cruise on '01. 5 and '02 manual trannys is through the computer, not vaccuum like the autos.



Truck is going back to stock to try to completely rule out the toys...

 

[Sick Boy]

Mine Is Showin No Codes At All, I Have An Auto An Dont Think I Can Use Th E Cruise To Test It Because It Does It When U First Start Out Between 1st An 2nd Gear About 10 To 20 Miles An Hour Once I Get Past That Point Its Fine

 

[magaliasram]

I am running a o1 Auto I am not sure if my problem is the same as yours I was towing my trailer and at hwy speed my rpm dropped to idle and the throttle was dead as a lame duck. I went home and removed all my grounds and cleaned them including taking the fender grounds down to bare metal. Left the batteries disconected the entire time and then did the APPS reset when I hooked them back up. The problem went away for a full year. When it came back I did the same thing again and once again another year of trouble free. I believe my problem was actually the APPS.

 

[Billy Diesel]

From what I have read, the manual transmission guys that had the APPS go out on them, they can accelerate via cruise control, because the cruise on '01. 5 and '02 manual trannys is through the computer, not vaccuum like the autos.



Truck is going back to stock to try to completely rule out the toys...

The truck has been VA only since the 10th, and has not acted up. This time included similar trips to the ones where it acted up before. I guess I get to put the APB back on and see if it acts up again... .

 

[Dr.Bob]

my son had the same problem with his 01 when cruiezing at 70 it would stay on the flats but when it came to a slight hill it would lose speed same power though then he would mash it to the floor and nothing if he played with the throttle it would come back he had a bad lift pump wasnt completely out so it aloud truck to run and a week later the injection pump was replaced because it still acted up with the new lifter pump problem has been gone ever since so i would say u have a bad lifter pump and bad injection pump

 

[wtfd6]

my truck is doing the same thing. it is throwing code p0216. all the research i have done leads to vp44. mine will do it with 14 psi fuel pressure. it sucks.

mark

 

[TurboTweaker]

Just what you wanted to here huh Will, INJECTION PUMP! been there done that not fun or cheap. if you need parts i might have some or just a warm shop to work in let me know im not that far away. if you need help just call i owe you a few.



The Fat Kid

Andy

 

[Billy Diesel]

No codes, so I am still praying that it was a bad connection somewhere. Can't blame a guy for not giving up hope!



Fat Kid - Thanks for the other. May have to take you up on that if need be.

 

[2-ND TIME]

Is there anyone that actually knows about these things??? Sounds like an APPS problem. Dead pedal should be APPS. Dead pedal could be taking out the VP

-44 through lack of luberication.

 

[crawler]

Sounds like symptoms of a bad VP-44, hopefully its just a sensor or APPS, but I doubt it. I've been through six VP-44 in the past none since over 2 1/2-3 years ago. Try this out (its nothing proof postitive, but just one more little "test"), when the pedal goes dead drop the truck to neutral and let it cruise at IDLE for 5-10 seconds. Then drop her in gear and see if your throttle response comes back, if so then it's a sign of a failing inhection pump.



To eliminate the TPS find somebody else with a 24V cummins and see if you can try his out on your truck, it only takes about 15 minutes to change one and it will either indicate that it is the problem or that it has no bearing on the situation.



Give me a call if you have any questions. I'm headed out of town and won't be around a computer till early next week probably.



Later,

Wes

SMDiesel.com

(903) 355-4475

 

[DLBurns]

I have the same thing

Intermittent loss of throttle at any speed!!!

We think it's the APPS, gonna put on a loaner this weeknd and see if that the problem.

Where the best place to get a good price on a new APPS?? these suckers are 4 bills!!!

 

[2-ND TIME]

They are twice that up here and for what I measure of pins 1/2 and 1/6 they don't meet what cummins say's they should measure. <125 ohms contact resistance. confused!!!!!! Could anyone else please measure theirs that works well. pleeeeeease. Pins 1/2 and 1/6

 

[KWells]

Big Red

New here... I had the same porblem and replaced the TPS and never had it again.....

 

[Billy Diesel]

Well, after 3 weeks of the truck running fine without the APB, I hooked the APB back up and the truck is instantly neutered again. I'll have to wait until Monday to see what Blue Chip recommends.