Im back with yet again with another 2.9 problem

[Zapper]

So my 2.9 has always had an idle surge problem that makes it sound like it has a big cam in it recentlyits startedto happen quite often, and it also runs insanely rich when it does this due to the amount of unburt fuel and black smoke out of the exhaust, ive replaced both fuel pumps, fuel filter, mass air flow/pressure, but i haven't touched the injectors, the idle air control is working properly and im not sure what it is at this point, im starting to think it may be the injectors but i have cleaned them out, and i only use ethanol free fuel so if anyone may have an idea as to what the problem may be i would greatly appreciate it.

 

[rusty ol ranger]

Pull the vacuum hose off the fuel pressure regulator and look for fuel in the vacuum line. If theres fuel in it the FPR is bad and can cause the issues your having.

If the idle is high AND surgeing it could also be a vacuum leak somewhere.

 

[Zapper]

Pull the vacuum hose off the fuel pressure regulator and look for fuel in the vacuum line. If theres fuel in it the FPR is bad and can cause the issues your having.

If the idle is high AND surgeing it could also be a vacuum leak somewhere.

Checked the fuel pressure and its around 40-45, checked all the vacuum lines and none are leaking and the fpr wasn't leaking fuel into the vacuum line, i even showed it to my autotech teacher and he was stumped it

 

[RonD]

Fuel pressure should be 30-35psi so FPR may be bad, with vacuum line unhooked FPR can let pressure get up to 43psi, maybe 45psi
But with vacuum hose connected and engine idling 35psi should be max

The high pressure fuel pump is capable of 80+psi, just FYI
But even at 40-45psi the computer should be able to limit injector open time to compensate for the higher pressure

Do the Clear Flooded Engine test to see if any injectors are leaking fuel
Shut off warmed up engine
Turn key on
Press gas pedal down to the floor and hold it down all the way
Try to START engine
It should NOT start or even fire, the fuel injectors are OFF, 0RPMs and WOT = Clear Flooded Engine mode for computer

If engine starts or fires then you may have leaking injectors, which would account for Rich running, but test throttle cable first
Engine off
Use a stick against the seat to hold gas pedal down to the floor
Open hood and try to open throttle plate a little more, if you can then you were NOT at WOT for the above test
Google: Ford Ranger throttle cable mod

Easy fix for stretched throttle cable
Repeat test once its fixed

If you were at WOT for the test then time to replace the 6 injectors

 

[Zapper]

Fuel pressure should be 30-35psi so FPR may be bad, with vacuum line unhooked FPR can let pressure get up to 43psi, maybe 45psi
But with vacuum hose connected and engine idling 35psi should be max

The high pressure fuel pump is capable of 80+psi, just FYI
But even at 40-45psi the computer should be able to limit injector open time to compensate for the higher pressure

Do the Clear Flooded Engine test to see if any injectors are leaking fuel
Shut off warmed up engine
Turn key on
Press gas pedal down to the floor and hold it down all the way
Try to START engine
It should NOT start or even fire, the fuel injectors are OFF, 0RPMs and WOT = Clear Flooded Engine mode for computer

If engine starts or fires then you may have leaking injectors, which would account for Rich running, but test throttle cable first
Engine off
Use a stick against the seat to hold gas pedal down to the floor
Open hood and try to open throttle plate a little more, if you can then you were NOT at WOT for the above test
Google: Ford Ranger throttle cable mod

Easy fix for stretched throttle cable
Repeat test once its fixed

If you were at WOT for the test then time to replace the 6 injectors

Tried the clear flood test and it still started, and yes i have done the throttle cable mod and it goes WOT, so i went ahead and got 6 reman injectors, but its too cold to even work on it much plus im swapping the rear axle soon once i have time and the ability to use a lift so hopefully soon it warms up enough for me to do the injectors...