QuestionQUESTION: My 93 F150 with 3000 six cyl is running terribly. I changed fuel filter, plugs, wires , cap, rotor and still has no power. It seems to idle well once I get it started. I dont know if it is fuel pump or pressure reg problem or electronics. We tried another computer and did not help it. Any ideas?
ANSWER: Well, the computors on these trucks do not fail often.
Does the check engine light come on when it is running? and are there codes stored? these codes will definitely help narrow down the problem area.
Also, you will need to check a couple or things:
Fuel pressure and quality of the fuel. ( allow some fuel to collect in a cup from the fuel line or schrader valve and see if water is present.
The MAF sensor(if applicable) is located in the air filter area. the sensor is a hair like wire and can plug with dirt if allowed to. be very careful cleaning these- I use a toothbrush.
Once the engine idles... what is the vacuum?
Did the truck just start running badly? or was it getting worse?
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QUESTION: It did come on some time ago but not lately(check engine)
I had a friend check for codes,,No stored codes
What should proper fuel pressure be?
I will look for the MAF sensor
Vacuum is very good
The problem has progressively got worse. It started doing it wiht front fuel tank some time ago, so I switched to rear, now it is doing it with rear and is worse than before, will hardly run
AnswerFuel pressure is 40-50 psi KOEO (key on engine off) when key is turned off, pressure should not drop more than 10 psi in 2-3 minutes.
KOER (key on, engine running) pressure is 50-60 psi.
Truck may run on less pressure, but not well.
There is no MAF sensor, but the MAP sensor is on the firewall.
