MBR

I have a 92 F150 with a 300cu,manual Trans, no cruse control. I have beenchasing a problem with little success. The truck has a hard time starting when it’scold, it will sit there and crank over, after about 5-10 sec it will fire up thenthe engine stalls right out. After the third or fourth time it stays running. OnceI have it running it idles a little high I get a koer test code of 411. While driving I get severe hesitation unlessI put the pedal to the floor then its fine. When I am cruising (foot barely on the pedal) she hesitates and bogsdown sporadically.
I have tested the vacuum system
Replaced the vacuum reservoir, EGR solenoid,hoses, EVAP solenoid, EGR valve and hoses
On ignition system
Tested ignition coil good
Replaced plugs wires cap and rotor
Engine manage
Tested IAC, EGR Position sensor
Replaced IAC, oxygen sensor, TPS, PCVvalve and breather filter
RPM are better ides around800RPM. Acts the same while driving,still get KOER test code 411

dan2286

Have you checked fuel pressure?

Chris_1

iTrader: (1)

You should have 50 to 60 lbs fuel pressure. Low pressure would cause those problems

dondon69420

I have the same problem on my 90 i6 5 speed I have 32 lbs of fuel pressure koeo and when I start it the pressure stays the same? Regulator or pump? I'm replacing the regulator within the next couple days ill let you if it fixes it

techrep

iTrader: (1)

Or Throttle body...

Chris_1

iTrader: (1)

Regulator should make the pressure drop even further when you have engine vacuum (idle). But at 32 psi you're probably looking at a pump, unless maybe your filter is really clogged.....