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new injection pump installed on 1995

7K views 6 replies 6 participants last post by  RPegram 
#1 · (Edited)
hi. this past summer i had to get a new p7100 pump installed on my 1995 ram with 276000 miles on truck .it is a automatic trany.i ended up buying on on ebay cause it was 700.00 $ for a manual shift trany which everybody said would be fine aslong as the fuel gets turned down.this is a new rebuild by mopar/cummins in mexico.my mechanic said the fuel is turned down at factory he and i dont need to worry about it.with this new pump i lost 2 mile per gallon and my trany downshifts hard.some times it shifts funny also.could this be from new pump settings. the truck idled at 400 rpm for years.maybe the new 750 rpm idle is difference in trany. ps.i bought this truck new in 95. thanks craig
 
#3 ·
400 rpm is a bit too low for cummins, you run it like that for very long and your engine will start to slobber.
 
#4 ·
Why was the old pump replaced? As for losing mileage, it could well be that the new pump was installed so that the timing is retarded compared to the old pump.
 
#5 ·
sorry i ment 750 rpm. the truck idled at 400 rpm for about 5 years and moter runs well as new. the p pump was replaced because it would run fine for a day or a week then miss badley spitter and eventualy die.after a couple of months of this would not start (fire).mechanic said bad plunger in p pump.my concern is my trany down shifting hard and some times slow upshift (mabe a slip) hoping its not because this manual shift p pump is giving to much horse power tearing my trany up.also wondering if this extra hourse power is my 2 mile per gallon loss.thanks
 
#6 ·
If its shifting weird, the TV (throttle valve) cable is probably out of adjustment. this is basically your and the engines input to the tranny telling it what the hell is going on. If its out of adjustment, it may think your trying to accelerate hard while your just accelerating normally. or it might think your at half throttle when youve got the hammer down (a very bad scenario because you have a high risk of burning up clutches)

As for the mileage difference. that could be due to many things. More than likely that the timing was improperly set or it has slipped. Even if it was a factory 215hp pump, your mileage would not change unless you have the hammer on the floor all day where you will actually use that extra fuel.

BTW, your 'mechanic' doesnt seem like the brightest bulb on the christmas tree. the manual pumps (whether a 175 or 215) both fuel harder than your original. the 175hp pump isnt a big worry, but a 215hp pump even with its factory calibration is going to be hard on the trans.
 
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