Engine/Transmission (1998.5 - 2002) 24 valve power loss

[HKeenan]

HELP! My truck has a very annoying if not dangerous malfunction somewhere in some part of this electronic nightmare called an engine control system. I'll be driving along-no load or anything-just going to work running about 70-75 or so and all of a sudden there is no power! It slows down to the 60-62 range and it just takes off lickety split like nothing happened. It may run fine the rest of the day or it may repeat the same thing every 1/4 mile or so. There's no consistency at all. I just replaced the MAP sensor this past weekend. It didn't help. The dealer couldn't find anything wrong-no fault codes or anything. VP44 is fairly recent too.



It has a 4" exh,275 hp injs,afe filter,fass, and edge ez. I disconnected the edge to see if that made any difference-none.

The truck is a 99 QC short bed 4x4.

again HELP!

 

[DavidC]

Maybe TPS?. TPS connection/wiring?.



Dave

 

[msperos]

Sounds like the apps do a search for the calibration reset for it. Mine did it at about 40mph sometimes. At the time it was still covered under the emissions warranty.

 

[dunncamp]

I have had the same problem of loss of power. I usually get the problem at highway speeds where I lose power and the pedal can touch the floor with no more power. If on cruise the pedal goes to the floor automatically. I have found letting the back to idle and then hammering down again seems to work but only for a little while. It may be 1 minute or 15 minutes, no pattern. It has set a check engine light but I have not checked yet. I have recently cleaned air filter, replaced map sensor, cleaned the iat sensor, and reprogrammed the apps. No luck. Any ideas? Problem happens when edge is on and off. Truck is stock except for edge comp, AFE,and straight pipe

 

[KcoleKennyc]

I had this problem twice. The first time it was the APPS. Every time it did this, the check engine light came on. After I fixed this, it started it again and it was the VP-44. Kept telling myself that it couldn't be until truck died in the garage. It never turned the light on but it did set codes. I tried several things such as unplugging the Edge EZ, changing the ECM, but it was the VP-44 that fixed it. Good luck, Kenny

 

[dunncamp]

Had the vp44 replaced last year after it died along with the other fuel pump. Thats when I learned and got gauges. So Im hoping its not the vp again.

 

[rkressg]

Try recalibrating your APPS.

To do this, disconnect your batteries over night (at least 3-4 hours). Reconnect your batteries, get in, turn the key to on (with out starting). Slowly push the accelerator to the floor and slowly release. This will recalibrate it.



You should also clean the connector on the bottom of the apps. To do this, get a 13mm socket and remove the three bolts on the front top right of the engine. They are connected to silver/grey metal unit, the bolts are in the pattern of a triangle. Remove these bolts and lift up. On the bottom of the black connected unit, there is a wireharness, disconnect it, clean it with good electronic cleaner, pack with di-electric grease and reassemble everything.



You might also want to do this with the wireharness on the ECM. You will need a 6mm hex key to remove the bolt in the middle of the wireharness connector. Remove, clean, grease, and reassemble.



See if this helps your problem.

-Rich

 

[Al Dahl]

Dead peddel

Mine did the same thing couldnt cure it till i replaced vp44

 

[wtfd6]

vp44 here also

 

[CyberRanger]

APPS on Big Blue replaced under warranty.

 

[CWebster]

Sounds like the APPS. Might also be the crank position sensor. I've had several go out on one of my trucks and it would have similar characteristics as you are describing. Crank position sensor is much cheaper also.



Chris

 

[RJPotts]

Mine does the same thing, exactly. 70-75 decelerate just a little bit without touching the brakes, hit the go pedal again..... nothing.

Lift pump just replaced, I guess its time for a VP44. Another few days without my truck, yay yay yay Oo.

 

[DavidC]

Another suggestion might be to buy the OBD-2 Software if you have a laptop. Hook it up and monitor the system. If it happens while your driving and you stop you can save the file and replay later. The software gives readouts on boost, IAT, APPS, TEMP and more. I use this quite often and have saved multiple files just to keep track of things. Beats throwing money at it.



Dave

 

[dunncamp]

Thanks Ill try the apps and obdII

 

[dunncamp]

I noticed driving with the comp off for several days has cleared the dash light with no signs of any problem power is back to normal. Could the comp be causing a problem? Edge Comp always on 3x5

 

[DavidC]

I noticed driving with the comp off for several days has cleared the dash light with no signs of any problem power is back to normal. Could the comp be causing a problem? Edge Comp always on 3x5

Yes,but check all associated wiring, Grounds,pump tap etc. before condemning the box. If you had a dash light (Check engine?) there should be a code stored.



Dave

 

[HKeenan]

I'm kinda new at this. My last one was a '90 250 Cummins. Absolutely the most bullet proof truck I've ever had. Over 450,000 miles and nothing I couldn't handle. The water pump went over 400,000 miles. The brakes front-over 300 and the rears-over 350. All original front suspension and original clutch in front of the 5spd. Valve adjust every 50-80,000 or soand no problems. I got spoiled big time, so I got a '99 figuring we'd be in tall cotton again. Wrong!Helluva nice truck though. Just a bit touchy with all this electronic garbage on it.

Now then what is the OBD-2 software and where can I get it? Because I'm going to figure this thing out if its the last thing I do. It does get a heap of frustrating though.

I'll Keep you posted as to my progress. And thank you all for the suggestions. This weekend I'll start on them.

 

[DavidC]

I'm kinda new at this. My last one was a '90 250 Cummins. Absolutely the most bullet proof truck I've ever had. Over 450,000 miles and nothing I couldn't handle. The water pump went over 400,000 miles. The brakes front-over 300 and the rears-over 350. All original front suspension and original clutch in front of the 5spd. Valve adjust every 50-80,000 or soand no problems. I got spoiled big time, so I got a '99 figuring we'd be in tall cotton again. Wrong!Helluva nice truck though. Just a bit touchy with all this electronic garbage on it.

Now then what is the OBD-2 software and where can I get it? Because I'm going to figure this thing out if its the last thing I do. It does get a heap of frustrating though.

I'll Keep you posted as to my progress. And thank you all for the suggestions. This weekend I'll start on them.

Software is free. You are actually buying the cable.

http://www.obd-2.com/



Dave

 

[Oliver88]

Where can I buy the OBD2 software for a laptop and how much does it cost?



thanks,

Greg Davis

 

[BStowe]

Dunncamp,



I believe Autozone will retrive your codes for you for nothing, I thought about getting the little harbor frieght obd II code reader for $40. 00 until I decided to go for the Superchip.



A simple 5 minite plug in can lead you right to the problem.



As for the thread originator my suggestion would be to first be absoloutly sure about the codes, it is definatley fuel related. If still nothing then I'd start with the fuel filter and then go to testing fuel pressure past the lift pump. Worst case scenario would be the VP-44.



Byren