I Might Just Know What I'm Talking About
Join Date: Oct 2000
Location: C-ville, VA
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Re: Test Yourself on Fuel Injection!
For starters, I will assume that "no start" means that the engine is spinning, but not continuing on its own power (the indication of spark leads me to believe that the distributer is spinning). This rules out starter and starting system.
Plugs firing rules out ignition system.
Fuel pump indicates that the fuel delivery system works, and that the fuel pump has gas (pressure had to be built up somehow).
I would next check that the after delivery fuel system (injectors and sensors) are functioning correctly. I may be able to rule out a faulty O2 as most systems go closed loop when they start. I don't think the throttle postion sensor or crankshaft postion sensor would cause a zero start condition, possibly rough running though.
As most autos (older ones) rely on vacuum to control them, I would check that all the vac lines are connected correctly. If they are missing, then they could cause a lean mix, but it should still start.
The injectors may not be firing. I would check for the smell of gas. If its a TBI, then it should have fuel vapor present at the bore. If there isn't vapor, then I would check for any loose wires or grounding.
Other than these possiblities, I would have to look into the tranny shifter arrangement as I previously stated.
I figure that it could be fixed in under 30 minutes, or longer than an hour.
Jeep...need I say more?