Please help
Thread Starter
Junior Member
Joined: Jan 2023
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you can have fuel pressure at the rail, but if injectors are not firing, then engine is not getting fuel.
if you spray starting fluid and it still doesn't fire/pop, then your problem is (almost assuredly) not for lack of fuel.
you indicate testing for 12v (and finding it), but in some cases, function is controlled/timed by providing ground (i.e. if pcm isn't providing ground then presence of 12v doesn't indicate function).
may want to invest some money with independent mechanic for some diag
if you spray starting fluid and it still doesn't fire/pop, then your problem is (almost assuredly) not for lack of fuel.
you indicate testing for 12v (and finding it), but in some cases, function is controlled/timed by providing ground (i.e. if pcm isn't providing ground then presence of 12v doesn't indicate function).
may want to invest some money with independent mechanic for some diag
5 Year Member
Joined: Feb 2020
Posts: 7,715
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i was suggesting that you might benefit from some professional diagnostic work. The example i gave about testing for 12v (without mentioning/considering the ground side) was just meant as an example of need to understand how the circuit is functions (and is controlled) before placing value on the test/confirmation for presence of 12v. Yes, most pros have high tech scan tools, but not saying that is what is needed to accomplish some of the basic fire and fuel testing.
2004 F150 5.4 Lariat
Joined: Dec 2012
Posts: 956
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From: Summerville, SC
Good battery voltage?
How about removing a fuel injector and cranking it to see if the PCM is sending it voltage?
Is the spark strong or weak?
You could pull a plug after cranking it to see if it's wet or dry. Wet would indicate weak or no firing of plug. Wet would make me suspect timing, i.e., PCM, timing chain, crankshaft or camshift sensor, or bad PCM ground.
Thats all I can think of right now to test to find the problem.
How about removing a fuel injector and cranking it to see if the PCM is sending it voltage?
Is the spark strong or weak?
You could pull a plug after cranking it to see if it's wet or dry. Wet would indicate weak or no firing of plug. Wet would make me suspect timing, i.e., PCM, timing chain, crankshaft or camshift sensor, or bad PCM ground.
Thats all I can think of right now to test to find the problem.
5 Year Member
Joined: Dec 2018
Posts: 4,444
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From: Ocean Springs MS
I worked on a Ford Ranger (200?) about a month ago and it would try to start on first attempt but never started. Removed a spark plug and cranked right up! Turned out to be failed converter blocking the exhaust path.