I have a 91 f150 302 efi it has a sputter to it at cruise speed.It is really noticeable around 35-40 mph at 1200 rpm. it accelerates fine but sometimes when revving it up in the drive way it will hesitate, but it wont do it twice in a row. Let it sit and idle a few minutes rev it and it will hesitate again. When I start it in the mornings it will rev up to 1000 rpm then fall down to 500 rpm. It will sit there for a few seconds then idle up to around 1500 rpm then slowly back off to 750 rpm like it is supposed to. I've put new iac,map,and tps, sensors in it along with plugs wires, d-cap, rotor button, fuel pressure regulator,and egr vacum soleniod. Checked egr valve it worked freely like it should.Ttested fuel pressure has around 30 psi with engine running give it gas it will jump to 34 psi. with vac line off regulator it will stay around 36 psi. Shut engine off and within 45 minutes to an hour the pressue fell from anound 34 psi to 20 psi. According to the computer at the good ol autozone it should hold 35-45 psi engine running or just with the key on. I beleive my pump may be weak or do i have other problems.

 

hello

 

can anybody help

 

impatient much???

lol

get new pumps.

 

Injectors/fuel filter ??

 

I replaced the filter first thing. No change. It does the same thing front or rear tank. The rear tank has a couple of psi more than the front tank. Tis the reason why I'm wondering if I have other problems. The only things I can think of is pump or injectors. With 178k I'm leaning towards the pump. Is there any way of testing the injectors? Thanks for any help in advance.