Engine/Transmission (1998.5 - 2002) Ppumped with poor mileage

[TBartlett1]

I purchased a P-pumped 24 V and get 10~13 mpg and it also doesn’t start very well. The engine has 20k on it since it was built. The builder that installed the pump and injectors (12 hole) said that in current tune it was good for 6oo rwhp and if the fuel plate was moved over it could build 800.

We talked and he said that different (smaller) injectors would help. I asked him if the pump would need to be recalibrated, he said no.

Wouldn't installing smaller injectors (less flow) cause excessive internal pump pressures?

I’m willing to give up HP for some mileage.

Advice on injectors and timing would be great.

 

[MD500E]

I have a buddy that had 2 different p-pumped 24 valves. The first one was at 700 hp had huge injectors and lots of timing. It got around 11 mpg, while the other was set up for about 500 hp with near stock injectors and more mild timing got about 17-18 mpg. It always seemed to get the same if not better milage than my truck which has about the same power. I would say smaller injectors would definitely help, especially if your truck makes smoke under light throttle.



Kevin

 

[TBartlett1]

Not sure which pump it has, the builder is rather tight lipped. I'm inclined to think stupid because the builder of the fuel & turbo system said that if the plate was moved it would be good for close to 800. I'd be happy with 4 to 500. Gota be able to afford to run it.

 

[TBartlett1]

Haven't done a thing yet. I've had some problems lately. The front drive shaft fell out of the diff yoke because the circlips were never put on the caps to secure them. Cost me $930. Also found that there were no bolts holding the P-pump on and now I've found I need to reshim the rear diff for excessive backlash & poor pattern. Then there is an oil leak to fix. But I'm getting closer to tuning!

 

[catoiler]

Seems to me like the builder should let you know what is in the motor as you are now the owner. I would not like to have something and not know what or or how it was put together.

 

[WestTN]

I would think 12 hole injectors wouldn't be very good for economy at mormal driving speeds. High flow injectors equal low pressure injection. That equals poor atomization and inefficient fuel burn.

 

[Rebel Ram]

Haven’t done a thing yet. I've had some problems lately. The front drive shaft fell out of the diff yoke because the circlips were never put on the caps to secure them. Cost me $930. Also found that there were no bolts holding the P-pump on and now I've found I need to reshim the rear diff for excessive backlash & poor pattern. Then there is an oil leak to fix. But I'm getting closer to tuning!

I hope you got a deal on that. With all those poor setup syptoms.

I have had some interest in a P set up for my 01 because I love the idea of totaly mechanical engine. (Completely love my 1st gens) From what I've read, the attention to detail makes the difference in success.