a few questions about my pump and engine

[james-93-12valve]

First does a high idle really help the pump out or does it hurt it.
Second will turning up my pump hurt the mileage and or the engine life

[peobryant]

Haven't heard a thing about idle hurting or helping a pump. It should be around 800 RPM though.

Yes, turning the pump up will decrease it's life. I'm not sure how much, but there is no denying that it will hurt it.

As far as fuel mileage, according to Pete, turning up the pump can actually increase mileage. It helps the fuel atomize better, leading to better mileage. That is if you can keep your foot off the skinny pedal though.

[dpuckett]

IF you keep an adequate fuel supply to the injector pump, turning it up (within reason) shouldnt shorten its life. The reason the older VEs went bad after being turned up was that the stock lift pump couldnt keep up with the extra demand, decreasing cooling and lubricating of vital internal parts.

[PToombs]

That is if you can keep your foot off the skinny pedal though.

Yeah, that's the problem right there!

[gear jammer 91"]

When I bought my truck the previous owner had removed the lock collar on the fuel screw and turned it in an unknown amount. With the pump set like that I used to get around 20MPG. With my truck tuned like it is in my sig I average 18MPG. I also drive it like your grandpa 90% of the time. That other 10% I can't see the sun in my mirror's. I've put a little over 40,000 miles on it since I got with no pump issues.

[TTipswprd]

I had my pump rebuilt and maxed by diesel injection of the rockies and they told me that if the fuel screw is turned in till its starting to idle high it is just causing extreme wear and the parts and springs with no real extra gains.

[dpuckett]

Stick a fuel pressure gauge on it and see what happens. If it stays above 3-4psi, you will be good til around 250hp, then you will benefit from more supply pressure and volume. Or just do what I did- upgrade anyway. I have a 90% stock engine (20psi is my boost max), but have the piston lift pump.

I think you need to find a new injection shop. Local guy here says you will burn the engine (EGT) before you do real damage to the pump. Experiences related here back that up, too. I had a nonIC 91 that had been flowing 1.5X stock fuel for a LOOONGG time, and had no appreciable wear at 270K.

DP

[TTipswprd]

Well thats what i was told and id figure he would know better than me being 18 years old. just tryin to give my two cents. take it or leave it.