dead pedal 2000 24v truck HELP!

[ahale2772]

hey guys so ive got the common issue of them funny round trucks playing electrical games, my issue is this im loosing a pedal signal to the IP, when driving down the road the truck will suddenly go to idle but only when the truck is above 1000 rpm, not 999 rpm but only at 1001 rpm will it do it, then if u let the truck go below 1000 the truck resets (u could drive from here to california under 1000 rpm and never have the pedal die, we have tested the throttle position sensor, cam sensor and taken out the edge programmer in the truck. none seem to change the issue, interestingly the only time it seems to do this is when the engine warms up if i start it up in the morning dead cold it wont do it for about five minutes of normal driving but after it becomes progressivily more agressive as the truck gets hot

i hear that the MAP sensor can be at fault but i cant see how it would lead to the truck dieing at exactly 1000 rpm

the pcm is recently new and the truck had some charging issues after the new computer, also the abs constantly works if plugged in so the pump is disabled,

im thinking that the portion of the computer / the vp44's internal speed sensor is going crazy above 1000 rpm

any other thoughts?

[ellis93]

First off I'm not an expert on vp44 pumps or the elect on the 24valves. Worked on several that if the pedal sensor is not bad, it was that box on the pump. First thing you need to have it scaned by someone with a real scan tool scan it to look at the sensor values ( otc ,snap on etc ) not that off the wall cheep part store crap. By doing this they should be able to tell u where to go to the pedel or pump. What I have seen is folks put the programmer on and set it hot and the pump will throw the fuel at the motor so hard that the supply pump can not keep up and the fuel that the 44 gets 25% runs the truck and the other 75 cools the pump and the black(or silver) box on top. My Pump shop has said that whenever there is not enough fuel that there is some timing stuff in the pump that galds up and the truck has multiple symptoms. This is one that they told me. The other is the box gets hot and fries. Hop this will help. If pump is the prob I have the number to a place you can get one for 1100.

[ahale2772]

the fuel issue was solved along time ago with a bluechip vp44 and a fass system thats why this is such a weird truck everything points to computer, the truck throws a code saying p1693 in powertrain and im told that means that that code is a conpanion code saying that there is an issue in the ecm? ughh i hate computers

[ellis93]

Mashed on the google button and fond this and others.
http://www.cumminsforum.com/forum/98-5- ... dal-2.html

[ahale2772]

yeah well thats the weird thing about the vp44 the dead pedal is a dual issue when the vp44 is dieing it gives the symptom of more of a "lazy pedal" where iit holds a constant rpm but wont accelerate, the issue we have is a complete loss of signal where the pump returns to idle still havent figured it out even put in a new ecu the other night

[burnt_servo]

have you tried reseting the " pedal " ?

turn the key on , but don't start it .

slowly depress the pedal to the floor , then slowly release it .

turn the key off

start the truck and see is anything has changed .

hope this helps .....




pulled this directly from "blue chips" site ;

http://www.bluechipdiesel.com/vp44diagnostichelp.html
"This is THE MOST COMMON DRIVABILITY COMPLAINT and is an intermittent one that happens most often when the truck is hot or working harder, but can occur much less frequently when cold too. There are no codes pertaining to “Dead Pedal” that will condemn the computer and therefore the VP44. This symptom of “Dead Pedal” is rarely caused by a faulty APPS (Accelerator Pedal Position Sensor) and 99% of the time it is caused by a faulty computer on the top of VP44 injection pump. These numbers are NOT an exaggeration. The best way to positively eliminate or condemn the APPS as the cause of the problem is to “scan" or read the ECM (not the PCM) in your truck to check for any DTC codes pertaining to the APPS, such as a 121 or 122. IF YOU DON’T GET THESE CODES YOU DON’T NEED AN APPS AND IF YOU HAVE DEAD PEDAL, cold or hot, YOU DO NEED A VP44! NO MORE DIAGNOSIS NECESSARY.

If you have a 2000 – 2002 truck you can get the codes by turning the ignition switch to the on position 3 times within 5 seconds and leave it in the on position and stare at the odometer. Write down the information you get and use it for your diagnosis. You can tell what computer you are reading by the number of the code(s) you get. If it pertains to the engine or fueling, then it is the ECM and if it pertains to the rest of the truck it is the PCM. If you get a 1693 that tells you there is at least one code in the other computer. If you have a 1998-99 or a grumpy 2000 this will not work, so you’ll have to get the codes with a scan tool. Most auto parts stores will do this for free for you. A possible pitfall here is if someone turned the key on when the APPS plug was disconnected. This will set an APPS code, so if you think this could have happened, clear all the codes with a scanner, recheck for codes to be sure all codes were cleared, then drive the truck until the dead pedal symptom reoccurs and then check to see if the APPS code returns. The worst case scenario is when you replace the APPS because of the code(s) and it doesn’t solve ALL your drivability issues. Then you have a bad VP44 as well.

If you don’t have access to a scan tool, and want to trust my experience, let me explain the difference in symptoms between a bad APPS and a bad computer on the injection pump. A bad APPS usually is just a flat spot at a certain throttle opening, usually 65-70 MPH, and smacking the pedal to the floor a few times, usually clears it up. If pushing the throttle just a bit more makes it take off, or if going back to a lesser throttle opening makes the engine run fine, then it is a bad APPS. This usually occurs most frequently, but not always, in cold and or wet conditions.

If it is caused by the computer, the “Dead Pedal” occurs at all throttle positions and the computer will only reset and play again if you let the pedal go to idle for a brief time and reestablish “Idle Validation”, or push the clutch in, or shut off and restart the engine, or just wait. The “Dead Pedal” happens most often when hot or towing, but sometimes occurs right after start up when cold"

[ahale2772]

yeah thanks that helps confirm our beliefs a bit my dad bought his 24v new and has been thru 3 vp44s that have had the dead pedal where it just sdtays at a certain rpm but never where it goes completly dead, these 24v's arnt cutting it for me