Engine/Transmission (1998.5 - 2002) Is it VP or MAP

[PTuszynski]

My '02 seems to loose power. I can start down a freeway ramp when engine is cold and the truck will not accelerate. I push the go pedal and its almost like the turbo is spooling up, nothing and the truck takes off after a second or two. Or I can be on the freeway,70mph, with the cruise on and it will loose power, try to accelerate with the cruise button and nothing happens, take off the cruise and mash the pedal, still nothing, let off for a couple of seconds and it is fine. It doesn't matter if the truck is hot or cold, and outside temp. I don't feel matters. The problem has been on and off for 6mon. or so. The dealer has installed the in the tank lift pump and replaced the APPS. They say the lift pump is not flashing any codes. I told the dealer I would consult the TDR experts for help. HELP!

 

[PSpychalski]

Sounds like the problem I just had. VP-44 went south. Check my earlier post on the 13psifp(idle)... . p0216 code... . Good luck

 

[PTuszynski]

Thanks, I am not monitoring feul pressure right now, next project I guess, but it does sound like mine. Although dealer says no vp codes are showing. I think I need to just change out the pump. Dealer said they would do it under warranty if it came to that.

 

[Steve St.Laurent]

I'd have them put a scan tool on it first and drive the truck - see what the map sensor is reporting. My truck did exactly what yours is and in my case I was able to took at my powermax remote (it uses the map sensor for it's reading) and it was reading 0 psi even though the turbo was making boost (on my other boost gauge). Once it got up to about 10 psi then the map sensor would start reading and it would take off. I cleaned the map sensor and that solved the problem.

 

[PTuszynski]

I personally don,t have acess to a scan tool but the dealer seems open to suggestions. What does the map sensor do and where is it located? I keep my engine compartment pretty clean and maybe it got wet. maybe I can just clean the contacts and try that first.

 

[Steve St.Laurent]

The MAP sensor senses how much boost the engine is receiving and reports it to the ECM. It's on the drivers side of the block just to the rear of the fuel filter assembly. There's two sensors screwed into the block there - the larger one is the MAP sensor, the smaller one is the IAT (intake air temp). I doubt it's the electrical connection as it's a weather pak connection but the sensor itself could be dirty. You could remove it and clean it with brake cleaner (that's how I clean mine) and reinstall.



The dealer scan tool plugs in at the bottom of your dash and can read in real time what the sensors are doing.

 

[PTuszynski]

I'll look into that today and try to clean it. Its like when you try something you have to wait for it to happen again. After they replaced the apps it took 2 weeks to happen again. It also seems to happen when the truck is below 1/4 tank of fuel, maybe just coincidence.

 

[mediccummin]

PT sounds like the same thing I am going through, I change or clean something then all is well and I think I found the problem, only for it to suddenly return a month or so later. Let us know what you find I will do the same, Good luck.

 

[CumminsFarmer]

When my rig did it 2 years ago, over a period of 3 months, it was the VP-44 slowly taking a dump. Dealer replaced both the lift pump, and the VP, and Ive never had a problem since. I installed a booster pump on the frame rail last spring, and have had good fp readings and great power ever since.

 

[PTuszynski]

I actually went to the dealer yesterday and took all my tdr info. They said they will order a new vp44 and call when its in. I will let you know how things go. Thanks for all the input guys!

 

[RJPotts]

When this loss of power happens, can you floor the go pedal without anything happening? If so I would call this the infamous dead pedal. Same thing happened to me before my VP croaked. Do you have any warranty left?

Good luck

-R. J.

 

[PTuszynski]

Yes it has a dead petal. The other day, it wouldn't go over 65mph on the freeway. It would struggle up hill and drop to about 55mph I could push the pedal to the floor and nothing would happen. then it would coast back up to 65mph going downhill but still not accelerate. It sounds like the pump is cavitating though, I can here something under the hood when I am at full throtle,which I assume is the pump. The truck has 53k on it and this started around 45k. But the dealer is changing their tune. After saying they would do the pump as their next option, now they won't do it until it totally quits or throws up the codes,which it hasn't yet. I don't the thing dieing on the road. They told me to call customer service which I did and they told me the dealer has to call the district manager. It sounds like the catch 22 is starting. But my truck is getting much worse so maybe the check engine light will come on or it will totally fail and I can get it fixed.

 

[John - K5AWO]

Dead Pedal, but floored it takes off again

When this loss of power happens, can you floor the go pedal without anything happening? If so I would call this the infamous dead pedal. Same thing happened to me before my VP croaked. Do you have any warranty left?
Good luck
-R. J.

My rig has been doing this off and on now for a few months. Haven't been able narrow it down to any particular thing. Although last week I let the fuel get down to 4 gallons (digital read out on my Trax system) and it went flat several times in one short trip. I spent $50 bux and on loaded 13 gallons of fuel. Seemed to have stopped the problem, and then it happened once more since then.

I am going to try to keep the fuel level above 12-15 gallons for a while and see what happens. I don't even want to think that the VP-44 is on its' last legs. My budget can't afford that right now.

The fuel pressure is always rock solid at 15 psi, the only way I can get the fuel pressure to drop is to floor the pedal and then it is still about 10-12 psi. This is with the stock fuel pump and location.

John

 

[JHudson]

My '02 seems to loose power. I can start down a freeway ramp when engine is cold and the truck will not accelerate. I push the go pedal and its almost like the turbo is spooling up, nothing and the truck takes off after a second or two. Or I can be on the freeway,70mph, with the cruise on and it will loose power, try to accelerate with the cruise button and nothing happens, take off the cruise and mash the pedal, still nothing, let off for a couple of seconds and it is fine. It doesn't matter if the truck is hot or cold, and outside temp. I don't feel matters. The problem has been on and off for 6mon. or so. The dealer has installed the in the tank lift pump and replaced the APPS. They say the lift pump is not flashing any codes. I told the dealer I would consult the TDR experts for help. HELP!

My truck did the same thing. It was the map sensor. I cleaned both sensor and electrical connection and checked my FMS (it reads the map sensor) and truck has been perfect now for three years. At first I thought it was going to be the VP-44 but it wasn't. Check the map first as from the dealer they are only 79 dollars if you choose to replace.