20 Most Recent 1991 Ford F150 - Page 8 Questions & Answers

it is shows more petrol in the combustion chamber check first sparkplugs put new plugs,if you have stil have problem the cylinder head needs to remove means valves inlets and exhaust to granding to make correct angle valve seat.

Check comp. Sticky valve or valves

You can try tapping the starter with a hammer slightly, and see if it starts, if it does then the starter is bad.

Hi Grorgge, At the brake light switch(lower pedal) check for voltage at both wires,should only have voltage on one wire, then while pushing the pedal down you should have voltage on both wires if not the switch needs to be replaced. Hope this helps, Dwight

Prob with Suzuki....blocked main jet or major air leak. Prob with F150 MAP Sensor disconnected or not functioning

Check your oil level. If it's anything like my truck, then the oil pressure gauge is whack. It could also be your oil pump is going out, or a vacuum hose has broke or worn through.

you may have a problem with the injector circuit.either bad injectors/dirty or the injector circuit has a problem such as connection or ecm.check for codes in the computer as this may help guide you in right direction to start diagnoising.could also be bad ignition components,incorrect plug gap or plug,wires,cap or rotor problem.does these cylinders have spark at the plug.i am guessing the problem was there before the tune-up.

If hoses seem Ok and the clap is tight it may be the Heater Core has sprung a leak, although is leaking outside maybe the line where the hose attaches has a leak.

i do believe that this model has a pump thats built into the tank sounds like you need to remove this pump and clean it of an obstruction I think a spring washer retains it into tank housing carefully pry this spring washer out and pump should slip right out completley clean pump and tank with soap and water carefull to not get electric parts wet

it might be a faulty pressure regulator. would check that. think it runs off the air line to open and close but some a electric. .

could be you fitted the thermostat in the wrong way around ,or the plastic impeller on the water pump with a steel drive shaft has failed they end up with the drive shaft spinning but the impeller is not turning ,go for the thermostat first though .

short needs to be found and fixed, try local mechanic shop.

Go to your local Auto Zone store and ask them to check your truck with their auto Diagnostic Tool and ask them for advice.

That would be called the shift interlock feature. It operates on the same circuit as the brake lights so the first thing you want to do is to make sure the brake lights are working when this problem is present. If the brake lights are working, that proves the circuit is good up to that point, then you'll have to get to the solenoid in the console. Disassemble as much as you have to to access the solenoid near the shifting mechanism. Us a 12v test light to test for power coming and going at the solenoid when the brake is applied. If power is arriving and switching and the solenoid is not triggering, the solenoid is bad and will have to be replaced.