Archived Dealer can't find the problem...tell me what you think it is.

[Redleg13]

I've had this problem for a couple of months or so now and although I can repeat it anytime I want to... . the dealership can't repeat it and said I should just keep driving it till it quits.



Well so much for their advice.



Its bugging the crap out of me and I thought I'd give you guys a shot at it.



Drive the truck for an hour or more at highway speeds... . 70-75 in 6th gear turning roughly 2300 RPMs, Water Temp 190 to 190+



Once those conditions are met (and it can happen at anytime after that)..... press the accelerator to speed up as if you are going to pass someone and nothing happens... . RPMs don't spin up and the truck does not speed up... . push the pedal to the floor... RPMs don't increase and it does not get any faster... . give it 1,2,3, to 5 seconds and all at once the power is there and it leaps like a rocket... . RPMs jump up and it takes right on off... .



Once it starts it happens in every gear and its usually when you are between 1000 and 2000 RPMs... . foot to the floor no power no RPM increase... .



The Fix?

Gear down... . get on it... and the power kicks in and RPMS jump

or

Shut it off for 20 to 30min and it won't happen again till you reset the conditions listed above.



I use my truck everyday and around town doing normal driving it never happens. It only happens when I'm out on the road.



Now the dealer drove it up and down the road and could not get it to happen.

I gave them the same description I gave you here and I was told it had not tripped any codes and it was not a fuel pump issue and that nothing was wrong. (Guess its just me)



But having just driven 6 hrs today and gotten fed up with it happening again I thought I'd tee it up for you.



What do you think?



Fuel Pump?

Turbo Problem? Waste Gate?



Any help would be great.

 

[FourBarR]

you havent told us what year your truck is. if its a 98. 5 or 99 get codes read . if its a 2000 or newer key on off ,on off, on off , then codes will be in odometer window, if there are any. sounds like either lp or vp44. apps could cause similar trouble. try recalibrating it. disconnect the negative cables from both batteries for several hours, over night is better. then reconnect turn key on but dont start engine, slowly push go pedal to floor, and slowly release. start and give it a try. good luck.

 

[wtfd6]

sounds like what my truck did. let off the throttle and power would come back. sometimes put in neutral then back in gear and the power would come back. sometimes i wouldnt even realize i was slowing down then the power would come back and set me back in my seat. do what FourBarR said. check for codes. hopefully you dont have the dreaded p0216. that is the death of the vp44. at least for the most part. after i changed my pump it was like night and day. hope this helps.



mark

 

[Redleg13]

sorry I thought I updated my info... 2002 4X4 Quad Cab 6 Spd... .



I have not tried to look at the codes for myself but as I noted the dealership said that the truck had not tripped any codes... .



I will take a look at the codes and try your fix



Thanks

 

[Redleg13]

you havent told us what year your truck is. if its a 98. 5 or 99 get codes read . if its a 2000 or newer key on off ,on off, on off , then codes will be in odometer window, if there are any. sounds like either lp or vp44. apps could cause similar trouble. try recalibrating it. disconnect the negative cables from both batteries for several hours, over night is better. then reconnect turn key on but dont start engine, slowly push go pedal to floor, and slowly release. start and give it a try. good luck.

Why would this only show up on long road trips at speed? Wouldn't a pump give some kind of indication during daily driving? Just curious and thinking out loud here..... I had a 99 3500 that had the VP44 and the LP go out on it and a waste gate go bad... . both pump problems didn't give me any indication of a problem prior to going dead... . and the waste gate problem left me with no power at all. Again just thinking out loud. Thanks again for your help.

 

[randrade]

This is identical to the situation with my truck. Driving along normally and suddenly no pedal. Took to the dealer and found vp was not working properly, replaced under warranty. I checked lp after and found pressure could be pulled down to 0 at wot but at idle it was like 12-14. I replaced lp myself just to be safe.

Rafael

 

[JoshPeters]

If you do a search for "Dead Pedal" you'll probably find more info than you can shake a stick at.



Josh

 

[Steve St.Laurent]

My truck was just doing something like this. In my case it was a dirty map sensor. I was able to figure it out by comparing my analog boost gauge to my electronic one on my PM3 (which gets its reading from the MAP sensor). It wouldn't read any boost until there was a significant amount of it and then it would take off. Because it wouldn't read any boost the ECM wouldn't feed any extra fuel. Try pulling out your MAP sensor and clean it with brake cleaner (or contact cleaner). You could verify this by putting a scan tool on it and seeing what the MAP sensor is reading when it happens.

 

[TheBigSgt]

My truck was just doing something like this. In my case it was a dirty map sensor. I was able to figure it out by comparing my analog boost gauge to my electronic one on my PM3 (which gets its reading from the MAP sensor). It wouldn't read any boost until there was a significant amount of it and then it would take off. Because it wouldn't read any boost the ECM wouldn't feed any extra fuel. Try pulling out your MAP sensor and clean it with brake cleaner (or contact cleaner). You could verify this by putting a scan tool on it and seeing what the MAP sensor is reading when it happens.

If it id still under warrenty, have the dealer try it.

 

[Evan A. Beck]

My '01 6-speed did the same thing, under the same conditions you describe. Bascially, once the engine got warm for any length of time, the issue would start to make itself known. No codes set, everything looked ok. Thats when I put my lab scope on the APPS signal circuits, and was able to finally see a 'noisy' signal coming from the APPS itself. Its pretty common to see these things fail around 110-120,000 miles. Mine failed at 118,000. Seems to be more common on the manual transmission trucks, mainly due to the fact us stick guys are on and off the throttle more often, which can create a wear pattern on the contacts in the sensor. The downside is that the part is about $350. Best of luck to ya!