Edit- Had to loosen valve core to be able to engage pressure gauge fitting. KOEO fuel pressure is 38 which is good. KOER fuel pressure is 28 which is low. Performed regulator check valve function test, pressure drops immediately. Pinching supply line, pressure drops in approx 15 seconds, pinching return lines, pressure drops approx 15 seconds. Checked voltage at fuel pump, 12 volts, checked fuel pump ground, 0 ohms. Pump is good.


94 v8 351. Takes a few attempts to get started first thing in the morning. After it starts it idles fine. And i can shut it off and restart it immediately with no problem. At low rpm and slow acceleration it runs/drives fine. As soon as i floor it or try and accelerate, the engine bogs big time. Replaced fuel filter and fuel pump in tank. Tried pressure test at fuel rail while running and while off, i hear the pump kick on, but don't get any pressure reading on gauge. Tried regulator test by crimping return line, still no pressure reading. Any tricks to this?

 

are you using an actual fuel pressure gauge. if you pull the vacum line from the FPR is gas present? Have you pulled codes on the motor, its possible the injectors are opening, but you should still get a reading on the shrader valve with the gauge. is the fuel filter facing the proper way?

 

Have not pulled codes yet. Gotta find out how. And i'll check the FPR(regulator?) Ill double check filter, but pretty sure. Thanks.

 

search as its well layed out on the forum. have you unhooked the battery and left it that way for 15mins and then reconnect and try?

also pull a couple plugs and see what they look like. check your oil and make sure fuel isnt present.

 

Searched for Koeo and koer, couldn't find what i wanted...the manual had it though. KOEO 11565565 KOER 116632116632 Filter is on correctly, plugs looked okay, gonna do a tuneup anyway...speaking of, pulling plugs on a bronco is ridiculous!! Pipes/lines and crap in the way for every plug!! Was easier swapping out a radiator on my Tacoma! No fuel in vacuum line And no fuel in oil. Test drove while warming engine up for test, and it stalled on me pulling out of driveway, took 3 times to get started and stay running, seemed like pressing gas pedal helped to start it...kinda weird...

 

Check pressure at fuel rail with a different gauge. Just because the pump kicks on doesn't necessarily mean it's pumping.

 

Something screwy with what you have there for both KOEO and KOER. From the look of it, the engine and transmission were not up to operating temperature when either test was administered as most of the Codes shown are "low temp" or "out of range" indicators for the transmission. Code 32 is typically indicative of a stuck open EGR valve, lack of vacuum to the EGR valve, or a bad EVP sensor. However, always check vacuum lines and wiring first.

 

with that year he would have 3 digit codes correct?

 

Your fuel pressure gauge needs to depress the test port Schrader valve's pin, or else your gauge will not read anything.

 

Hey GreyStreak, does the 94 use an inertia switch in the passenger foot well anymore? Might check the wiring to that?

 

Inertia switch works, after depressing and running vehicle, it chokes out and dies. Just replaced cap, rotor, plugs, wires, and no change. Will test EGR/EVP and vacuum tomorrow.

 

Oh ok, figured i would toss it out there, had a similar problem with a fast truck..

 

EGR has no vacuum from the line. Cant find crack/leak in line...

 

Any links to vacuum testing procedures on this forum?

 

Replaced EPV sensor, no change. Cleared codes by disconnecting battery. Drove around town for a a bit then re-checked codes KOEO 565 KOER 632

Still not getting any vacuum at idle or high rpm at EGR. Vacuum canister has no leaks.