Please HELP!
Thread Starter
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Junior User
Joined: Jan 2011
Posts: 79
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Does the truck stay running if you apply the throttle? You've got ignition since the truck starts and runs. I'd be looking into fuel management/sensor problems at this point. TPS, IAC, and MAP come to mind. The MAP sensor relies entirely on a "closed" vacuum system for it's signal, so if there's a broken vacuum line somewhere, it will cause problems.
thanks for your help.
Senior User
Joined: May 2010
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You say the fuel pressure increases with the truck running?
Generally speaking it should decrease, not increase.
Could be the computer as mentioned, may also be dirt/gunk in the injectors/fuel rail. Here in florida sometimes fine sugar sand will find its way through and clog things up. I have had it cause a very similar problem to yours, evidently it moves around a bit and lets some fuel through until its gets pushed back and blocks the injectors.Not positive what is actually occuring, but when you clean it out it fixes the issue. I would guess other types of debris could cause the same thing.
I've also had one bad injector mess up the whole system, but so far that only seems to happen after the engine has run enough to get warm, or it fails to start at all.
Generally speaking it should decrease, not increase.
Could be the computer as mentioned, may also be dirt/gunk in the injectors/fuel rail. Here in florida sometimes fine sugar sand will find its way through and clog things up. I have had it cause a very similar problem to yours, evidently it moves around a bit and lets some fuel through until its gets pushed back and blocks the injectors.Not positive what is actually occuring, but when you clean it out it fixes the issue. I would guess other types of debris could cause the same thing.
I've also had one bad injector mess up the whole system, but so far that only seems to happen after the engine has run enough to get warm, or it fails to start at all.
Thread Starter
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Junior User
Joined: Jan 2011
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Yes, fuel pressure increases from idle / 32 to almost 40 when throttling it.
I did the static test, KOEO - all is ok. IT won't run long enough to do the running tests.
I did the static test, KOEO - all is ok. IT won't run long enough to do the running tests.
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From: Edmonton, Alberta
I'd go to a junk yard and grab some cheap yellow top 19lb injectors. Maybe yours are all gummed up. If it runs then have your old set rebuilt or buy new ones. If you know of someone that has the same truck as you, try your engine control management (ECM) in their truck. See if they have the same issue.
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Junior User
Joined: Jan 2011
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Any place have a decent step by step to remove the fuel rails on this '87? I hate to tear into it and waste time. Looking at it it almost looks like the plenum has to come off to get to the pass side injectors ..
