1987 Ford F-150

2 WINGERS

MEMBER
1987 FORD F-150
V8
2WD
MANUAL
60,000 MILES

When starting cold it sputters, backfires, and runs very rough. You must keep the rpms up or it will just shut off. I have to let it warm up some before I try to move it or it will just choke down. It skips, pops, coughs up to highway speed then it will generaly smooth out untill you mash the gas again, then here we go all over again. The slightest little hill causes it to go into convulsions again. I suspect fuel pumps or pressure regulator or something along that line.

Any Ideas?

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires

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Monday, May 11th, 2009 AT 12:53 PM

2 WINGERS

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1 POST

I guess I should have been a little clearer with my initial question. I have already changed
fuel filter
plugs
wires
coil
MAP sensor
TPS sensor
TB ERG valve
checked for vacum leaks
been through several tanks of fuel

I guess that leaves pressure regulator, fuel pumps, or injectors.

What's your best guess? Truck runs fine at highway speed. It's just when cold or accelerating when it give the biggest problem.

You mentioned cleaning the injectors. Are you talking putting some type of injector cleaner in the fuel or removing them and cleaning them?

2 Wingers @ wits end

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Monday, May 11th, 2009 AT 10:27 PM

RASMATAZ