ok you mechanical masters.......

[bajascott]

ok, i have been having some issues with my bronco. sputters and pops like a vw running lean with dual carbs....the best way to describe it
when i went to Vatozone i had them pull the codes. 33 and 41 think is what they were,
anyway, egr not working,i know that been that way for years, and heoc somthing or other was lean.
after talking with a few people,i figured the low pressure fuel pump was bad.just installed a new one today( thank you very much Devin!!) it still does it.,so my next thing was the regulator on the fuel rail.
any of you gurus have any ideas?
i havent changed plugs, wires, cap, and rotor yet(they arent that old)
i am going to be getting away from all this F/I stuff soon but i need it in ship shape for an exploration run in paisley the 9th...
and dont have all the parts yet..

[bajascott]

changed out the vacum regulator...nochange.if the high pressure fuel pump was going,would just go out?or would it loose a pressure?
when i add throttle,and let off the idle drops alot and themn picks back up.........

[SteveG]

Fuel pumps don't always just stop working. Sometimes they lose pressure. Are able to check fuel pressure?

[bajascott]

no i dont have access to a gauge, i have a new pump,i just diddnt want to use it yet.
it is weird, it intermitantly wants to die out as well.
i'll try and locate one tomorrow what are the pressures supposed to be at?

[Nick]

no i dont have access to a gauge, i have a new pump,i just diddnt want to use it yet.
it is weird, it intermitantly wants to die out as well.
i'll try and locate one tomorrow what are the pressures supposed to be at?

Fuel pump relay?

[300]

I believe the pressures should be in the mid 30 to low 40 psi range if stock. If you disconnect the pressure regulator, the pressure should jump up if the regulator is working correctly. They will have a pressure gage made for this at Vatozone. If it doesn't have a consistent idle, be sure to check the idle air valve. They will stick, get gummed up or fail, which will cause the operation you describe.

[Dust]

Fuel filter every 5-8000 miles depending on fuel quality. Use Ford or Wix/NAPA
Fuel pump High pressure.
Damaged Return line.
Damaged flex line after the HP pump.
After that dirty injectors.

[Polarcub]

This is not my strong area but if your EGR is stuck in the open position it will cause you to run weird. Had this issue on my F350 a few years ago and it sounds like your having similar issues. If your running a basically stock setup there isnt all that much to go wrong on the fuel delivery side. Just a thought hope you chase the problem down soon.

[RSR]

I agree with Polarcub. I think you have an EGR or PCP valve problem, not a fuel problem. Possibly even an intake manifold leak. That computer will make your truck act like you have a fuel problem when one of these problem above exist. Let us know what it was.

[bajascott]

i havent had a vacumm line hooked up to the top of the egr thingy since i've owned this thing
all the vac lines coming from by the coil have never been on this in two years....
whats a pcp valve?

[johncharlesb]

As you know you are too lean. It could be too little fuel or too much air.

Get a fuel pressure gauge rented from your local discount auto store. Get it to "act up" and check the pressure. If it is low, you know where to start. I would make sure that high pressure pump is good. Fuel pumps can be very intermittent when they fail. Some have been know to drive around with the gauge taped to the hood to monitor the pressure. Others will put it in the engine bay and drive around until the engine falters wherein they will quickly stop, then run out to check the pressure.

The air can be a couple of things. The pcp I am guessing is the Positive Crankcase Ventilation system that vents the motor by sucking air out of the engine. The computer anticipates this air and may not be happy without it. The EGR or Exhaust Gas Recirulatory system introduces exhaust (inert) air into the intake to control exhaust temps during deceleration. It is closed during idle and powered situations. Even unhooked it can fail and allow gases to recirculate (the body can fail, rust, get leaned on, or the valve gets stuck on debris), this will make the engine run rough on idle and low on power. You sometimes can reach under the vacuum canister and pull up on the diaphram lifting the valve. It should have tension holding the valve down when you let go. If the engine is running fine with it unhooked and it seems closed, I would leave it. I doubt this is your problem.

I suspect it is the high pressure pump, but it can be anything really. I would check the egr, pcv, and all vacumn lines first. Next, I would check the fuel pressure. I suspect it will be low and would put in a high pressure pump.

John

[bajascott]

im going to install a new high pressure pump this morning,i have one and i'll know for sure that both pumps are new etc.
as far as vacum line go, i have none of the smog stuff,ie. coffee can or any of the related lines hooked up.i know that is part of my economy problem,but i'll deal with that.no vacum leaks any where.
but today,new plugs,wires,cap rotor,fuel pump.and im going to search out any electrical shorts,just to see......
i'll update later.

[bajascott]

k....all new pumps,filters,cap rotor,(wires and plugs were in great shape)
runs great!.......but it wants to just die at the wrong time(stop light)
i took it in the garage,and started shaking every wire and loom even cut loose some zip ties to make the harness' move more freely
nothing,i figured it was a short some where ,bad connections etc....not
so i looked at the tps plug and unplugged it while it was running and there was no change in idle or open throttle.
is that right? i thought that it would run funny if it was disconnected.
any ideas??

[johncharlesb]

"Runs Great!" means it runs better/right/like before? Is it an improvement?

Usually, if they die at the light, or coming off the throttle, it is a vacuum leak. You can spray something volatile around the intake gaskets and see if the revs change.

If it is just dying at low revs, it could still be vacuum, but might also be ignition, like the coil. A poor coil may also perform poorly under load, or at high revs. If you have one sitting around, you might want to change it. Check and clean the leads, the coil face, and the wires coming into it. Check the resistance on the primary and secondary windings. Good luck!

John

[bajascott]

runs great as in no more sputter under load,and flogging sound under throttle.
the connections on the coil are good, i cleaned the connections.
it runs better than it has in a long time exept for intermitantly shutting down.
what bout the tps? should it run differntly if unplugged?

[johncharlesb]

The tps can cause issues at idle. You will need to check it with a voltmeter.
http://fordfuelinjection.com/?p=30

[bajascott]

not tps....its fine. i got some other issues i think,gonna figure it out.
thanks for your input john

[poolman]

I would take off Idle Air Control Motor (IAC) you can clean them out or replace pretty easy,pm

[bajascott]

did that poolman.
i am going to replace the ignitor on the distributor today. a buddy said that he had a simaler problem with his dieing said that was his problem. after i do this.........it should be good.i hope.

[gr8brnc]

My buddy had the same issue and that fixed it..... after the distributor was put back in correctly since he didn't mark it before he took it out