fuel pressure problems...maybe
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Joined: Oct 2008
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fuel pressure problems...maybe
alright folks this is my first diesel, so bear with me. i went from getting 17.5-18 mpg down to 11 mpg. could not figure it out, then i noticed a nice puddle of fuel under my truck, and that the intake valley was full of fuel as well. thinking it was the fuel pump i began to disassemble the top of the motor to get to it. at that time i noticed the fpr screen to the filter canister was completly clogged (had to scrub it with a wire brissle bruch to get the gunk off). put it all back together after a good clean-up. so far so good, no more leaks. however, when i checking my fuel pressure it was bouncing between 50 and 60 psi (needle bouncing very rapidly). now on my old chevy small blocks they would bounce, but only between 1-2 psi. is this normal on these old diesels or is there something wrong that i need to check? i am goin to shim the fpr next week to about 75 psi, and throw a tuner on it. but i want to make sure it is running top notch before i do this. should i take the average of the bouncing and that is what it is reading say 55 psi +or- 5 psi, or what?
clay
clay
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Joined: Oct 2003
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From: MICHIGAN
Yep, that's common. It bounces so much that the california emmisions engines used a
damper on the pump. I guess there thinking is the engine may be over-fueled due to the pulses. IDK?? Use the highest number for the reading. I shimmed one up to 90psi and the filter canister lid would bulge up and down. 75psi should be good. BTW: I've never heard of clogged FP screen causing a leak?? You might want to keep an eye on things after you shim it.
damper on the pump. I guess there thinking is the engine may be over-fueled due to the pulses. IDK?? Use the highest number for the reading. I shimmed one up to 90psi and the filter canister lid would bulge up and down. 75psi should be good. BTW: I've never heard of clogged FP screen causing a leak?? You might want to keep an eye on things after you shim it.
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i replaced a few hoses as well that looked a little rotted, looked like the fuel pump was relatively new. i ran it pretty hard last night after putting it together and i saw no evidence of fuel in the valley or on the fittings. i will definetly keep an eye on things after i shim it. i am goin to do it tonight at work and see what it does. i am thinking about sending my IDM to beans for a 140v upgrade and then sending my PCM to DP-tuner for a 100hp performance tune. the truck already has a banks fast spool/high boost turbo, mandrel bent 3"ss downpipe to a 4"ss exhaust with the cat deleted.
clay
clay
