Hesitation between 35-45 mph

[Wingsfan14]

Starting at around 35 mph to around 45 with light pedal i get a severe hesitation in the engine, where it feels like its almost not getting fuel, it jerks badly ,if i let off the gas or give it more its fine. i just replaced the IAC for a differant problem so that shouldnt be it. Im wondering if my fuel pump may be going south or a fuel filter problem since its older thyen dirt. This is on a 91 5.0 bronco

 

[ocalabronco]

since you mentioned it, might as well go ahead and change your fuel filter, it wont hurt anything. have you tried to pull any codes yet? that should tell you something

 

[Wingsfan14]

since you mentioned it, might as well go ahead and change your fuel filter, it wont hurt anything.  have you tried to pull any codes yet? that should tell you something

31562[/snapback]

​

The check engine light only comes on after driving for about 10 min,when ya shut off truck and restart its gone then comes back. I took it to autozone to pull the codes but we couldnt find the hook up for the machine /emoticons/[email protected] 2x" width="20" height="20" />

 

[underdogdlr]

Starting at around 35 mph to around 45 with light pedal i get a severe hesitation in the engine, where it feels like its almost not getting fuel, it jerks badly ,if i let off the gas or give it more its fine. i just replaced the IAC for a differant problem so that shouldnt be it. Im wondering if my fuel pump may be going south or a fuel filter problem since its older thyen dirt. This is on a 91 5.0 bronco

31554[/snapback]

​

You are probaly experiancing another problem you did not mention as well like when you are driving either in the city or the highway when you accerate and let off and lightly get back into the gas it sort-of jumps or bumps making you feel like the transmission is acting up. If not then the problem is just now in its weakest point. Go ahead and change the fuel filter yes and the fuel pump relay. If the problem persists then give me an email @ [email protected]. This should fix the problem. If you put it on the scanner to find a code you will not have any luck. As odd as it seems. If you have unplugged the EGL Valve or MAP sensor make sure you disconnect the battery before this evolution and touch the neg. and pos. together for about 5 seconds to clear the system. I hope I have been of some help.

Ohh...BTW...you have two fuel pumps. I LPF Pump in the tank and an inline near the fuel filter. When you change the fuel filter becareful when taking the lines off that you do not get sprayed in the face with the pressure that is built up. If you have access to a fuel line pressure gauge it should have about 35psi of pressure reading minimum. I have an 89 Bronco and been there fixed that is my motto. I am about to remove the dash to get the heater door working which I beleive is not opening for the heater to work.

D...

 

[ocalabronco]

they're too stupid at autozone to know where to plug in the scanner. go to www.fordfuelinjection.com, and read on how to manually pull codes there. bookmark the site, it has all you ever need to know about ford fuel injection systems