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Old 03-24-2010, 05:45 PM   #2
MT-2500
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Re: 92 S10 W Blazer 4WD Fuel trouble

Quote:
Originally Posted by LarryGLack View Post
This is old type much-discussed trouble. If its already been posted I would appreciate a link to it! ;-) I did find many discussions but not the exact trouble I have...

This '92 CPI 'W' 6 cyl sat for about a year and a half with the fuel tank full under a carport. It ran fine when I parked it. The plates expired from Alaska and I waited till I got it here (Missouri). I had to put in a new battery. It started up instantly and ran fine. I had planned to replace dist. cap and rotor before I quit using it. I had the parts when I quit using it, but didn't change them till now. I changed those, started it up after and it ran fine. Shut it off and the next time I attempted to start it would not fire a lick. I checked spark and it is good. Checked fuel pressure and it was 45 lbs. cranking and holds when not cranking. I had replaced the pump about 18,000 miles ago...!* drat. So I went and bought a new one at the parts store. Checked the pressure again before taking it apart. Had 50 lbs and it started and ran fine. Checked it a few more times and got 54 lbs running and jumps up to 64 when the gas pedal is 'goosed'. Waited till the next day and it would not start, pressure at 48 lbs cranking. Starts and runs fine if primed with a little fuel. Powers up hills easy and is very 'peppy'. No black smoke out of tailpipe. Do you think its possible the regulator is flaky? The poppets and associated parts were replaced by a WA. shop, (I was not in WA. state at the time about 15,000 miles ago) I don't know what was replaced, but it cost $500.
Specs are 54-64 lbs fuel pressure.
You need around 62 lbs pressure engine cranking on a cold start for injectors to squirt.
Run a full fuel presure check.
Engine cranking cold presure?
Engine running on road pressure?
Check for fast leak down pressure?
Block return line and check full fuel pressure?\
Check fuel direct pressure into fuel filter in line?
Good fuel pump should be up over 90 lbs direct pressure.
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