power problem
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power problem
hi there all, this is my first post, so here goes, i purchased a 1986 f-150 eec-iv efi set. it had a definate cutout continuously in the power apply. i replaced brain, throttle sensor, mfi, injectors, dist modual, egr,temp sense,knock sensor,fuel pump, fuel pump switch,, then i bought the code reader ( iknow, i shoulda done that first, i am the old type and now i know) any way, i timed it to tdc 10 degrees before, and i ran the codes and all is well, got the 11 on the koeo and the koer. now here is the problem, starts and idles great, no miss goose the throttle, instant response. but i put it in gear and start off( i have the od automatic and it is a 4wd) starts good, but when i start accessing the power she bucks like a horse, like a broken wire or losing fuel pressure. i pulled both tanks and checked the internal filter. any help would sure save what hair is left on top of my head, i have a whole bunch on the floor from pulling it out.
Michael
Michael
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Joined: Mar 2002
Posts: 19,402
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From: Bonita Springs FL
You didn't say what engine you have, but it sounds like a fuel injected 302.
To me, it sounds a lot like a failing fuel pump that's not putting out enough pressure. The injectors need to see about 35 psi in order for everything to be happy. It could be a plugged line, a bad FPR, or more likely, a bad fuel pump. Your fuel pump is on the driver's side frame rail under the cab. If you can rent/borrow/buy a fuel pressure gauge, that will confirm it's the problem.
It *could* be a fuel filter, but it would have to be REALLY clogged in order to cause the problem.
To me, it sounds a lot like a failing fuel pump that's not putting out enough pressure. The injectors need to see about 35 psi in order for everything to be happy. It could be a plugged line, a bad FPR, or more likely, a bad fuel pump. Your fuel pump is on the driver's side frame rail under the cab. If you can rent/borrow/buy a fuel pressure gauge, that will confirm it's the problem.
It *could* be a fuel filter, but it would have to be REALLY clogged in order to cause the problem.
Junior User
Joined: Aug 2005
Posts: 76
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I have the same problem but only after I drive acros town.?
Originally Posted by andym
You didn't say what engine you have, but it sounds like a fuel injected 302.
To me, it sounds a lot like a failing fuel pump that's not putting out enough pressure. The injectors need to see about 35 psi in order for everything to be happy. It could be a plugged line, a bad FPR, or more likely, a bad fuel pump. Your fuel pump is on the driver's side frame rail under the cab. If you can rent/borrow/buy a fuel pressure gauge, that will confirm it's the problem.
It *could* be a fuel filter, but it would have to be REALLY clogged in order to cause the problem.
To me, it sounds a lot like a failing fuel pump that's not putting out enough pressure. The injectors need to see about 35 psi in order for everything to be happy. It could be a plugged line, a bad FPR, or more likely, a bad fuel pump. Your fuel pump is on the driver's side frame rail under the cab. If you can rent/borrow/buy a fuel pressure gauge, that will confirm it's the problem.
It *could* be a fuel filter, but it would have to be REALLY clogged in order to cause the problem.
Post Fiend
Joined: Nov 2001
Posts: 14,947
Likes: 6
From: Topsfield, MA
Yup, the spout connector has to be out in order to time the engine. This keeps the computer from playing with the timing, removing the spout allows you to set the BASE timing of 10 degrees. If you put that spout back in, and check the timing again, the computer will advance it on its own to about 20 degrees. If you don't have the spout out, you'd be setting the base timing at 0 and if so, it will make the engine cut out at higher RPM, 3000ish +...
Sounds like you need to do what Andym said and check the fuel pressure, but also check it under load. A troubled fuel system can put out proper pressure at idle, but unable to at WOT or high load.
Sounds like you need to do what Andym said and check the fuel pressure, but also check it under load. A troubled fuel system can put out proper pressure at idle, but unable to at WOT or high load.
