Engine/Transmission (1998.5 - 2002) Performance Issues

[Pmaloney]

Well I am having a performance issue I hope you all can help me with, I just today installed a reman VP-44 due to the fact that the old one was cutting out when cool in the mornings and sometimes during the day also was bucking at times, anyway with the new one it seems sometimes it is low on power, pedal to the floor and boost wont rise fast almost like it is not being fueled enough. When I reconnected the batteries after the VP install i fully depressed the pedal three times then attempted to start with no luck due to the need for bleeding the fuel system. So anyone have any ideas, I do not have a diagnostic connector hooked up yet so I cant pull codes (if any) I also used the keyway that came installed on the pump from www.cumminstuff.com

Thanks , I hope it is something cheap and simple (BTW fuel pressure at steady 14 at idle and doesnt change much under load 1-3psi change) All of this is with comp box off.

 

[Gary - K7GLD]

Apparently, it is possible for minor timing issues to occur when installing a pump - the key between the pump shaft and it's gear can be installed to slightly advance or retard pump timing, and care must be used to be certain the new pump/gear is timed as the old one was. Never did one myself, so don't have the precise particulars, but hopefully someone who's been down this road will comment with more detailed info...

 

[AKAMAC]

Just throwing darts here... ... CPS? Map?



A lot easier to swap out. Mike

 

[Gary - K7GLD]

A lot easier to swap out.



I'm reminded of a story where a fella out for a walk after dark ran into a guy ernestly searching for something on the ground under a street light - first guy asks, what are you looking for - the searcher sez, "I dropped my keys, and am looking for them". First guy asks about where did ya drop them? - searcher sez " about a hundred feet back THAT way". First guy sez, then WHY are ya looking HERE for them - searcher sez" the lights better here"...

 

[Pmaloney]

Well for a little update, I just got back from driving it 25 miles and it was fine the whole time, I ran half of the drive with comp off and the other half a 2x3 never had that hesitation/low power problem. Tomorrow morning I will see if it acts up when cold. I am hoping that mabee the ECM just needed to "learn" the new VP-44 and that I dont have a APPS going out, my wife will hang me if I tell her we also need a 500 part:--)

 

[Pmaloney]

Well as a bit of an update, it seems to run fine so far other than a long crank most of the time even if I just start it right away before I build too much fuel pressure and this morning while it was idling it just missed, like a gas engine that looses a cyclinder momentarily, Any ideas on the above issues?? The extended crank is driving me insane

 

[Pmaloney]

Well for another update, the intermittant low power is back normally after it cuts out, the tach will bounce and come back normally when first driving it in the morning or after work this will happen for 2 miles (the cutting out) then will be fine other than the low power which will continue for about two more miles than all is fine. This cutting out is irratating and so is the extended crank. Mabee I have a crankshaft sensor going out and it is going into a limp mode for a while (low power) I just cant see it being an APPS. I would think I would have a dead spot in the pedal not complete low power across the travel of the sensor?

Please all of the gurus out there I know someone has fought this and must have an answer it is really *$#%^@& me off, somewhat embarrasing to here it sputter and slow down. I dont want to throw darts but I am really thinking cran sensor

 

[bluestreak]

might check the throttle pos. sensor. mine would run down the road and miss. cough

and allmost die.