Sluggish or no throttle response

[PMalin]

I have a 2001 Dodge ram turbo diesel 3/4 ton p/u. When I start it up and keep it in park, the throttle responds and the engine revs up ok as expected. When I place it in gear i get very sluggish throttle response. It seems to improve some if it has warmed up or ran a little. I recently changed my fuel filter and suspected it so I changed it again. The new filter seemed to have no improved effect, not even for
a little while. I ordered one of the fuel pressure gages and just bumped the starter to let the lift pump run alone and was initially getting 4-5 psi but after a few seconds it then jumped up to 9 or so psi. Then I smelled diesel fuel to find out the fitting for it did not seal off real well. The gage comes with a fitting also, does this mean I needed to change that fitting also on the back side of the fuel filter canister? if so, I can retest. I was wanting to tape the gage so I could take it for a drive but if it leaks fuel, I am not going to do that just yet. I know the lift pump has been a big problem for the stock setup but would it cause these symptoms? I changed the lift pump once a few years ago but maybe it's time to do this again, but I dont recall the old pump causing this symptom. While discussing lift pumps what are the better solutions for this? Relocation kit? Fass stock replacement? Other? and if this is not what the problem is, what else should I check to locate the problem?

Thanks in advance..

 

[Missouri Mule]

It mite not be a fuel problem. You should have a tps or accs. Another words you have an electronic fuel/go pedal.
The best thing to do is go to auto zone or another part store that has code reader. Yes I know it revs fine in park. But something is not working right. Could be trans/ torgue or clutch....
Try spraying connectors on ecm and pcm if it has one with contact cleaner.

 

[PMalin]

Fixed it today, now I can hit the throttle and it goes like it should. Replaced the MAP "manifold air pressure sensor" for about $90. Ordered one from Geno's. The theory on this is that the computer will not allow the injector pump to fuel up more than the supposed air pressure boost is present on the intake manifold. The sensor that reports this is the Map sensor. Bad sensor results in dead pedal when hitting the throttle. I suppose the computer programming in it seems like it doesnt care about this if in Park or Neutral but if in gear then it wont fuel up more than the pressurized air is there for it in the manifold.

 

[DavidC]

No codes or check engine for the map ?. Guess it would pay to have a live data scanner.

Dave