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Fuel injectors not firing


bmostowy

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Good evening, TRS. Haven't posted much here, so I apologize if I do anything wrong.
What I've got:
1994 Ford Ranger 2.3L 5spd
What the problem is:
Fuel injectors are not firing.
What I know:
I have 12 volts at the hot wire(s), but the ground pulse isn't coming through. If I ground them manually, they do fire, and the ground wire(s) are continous back to the ECM. I have correctly timed spark, so the CPS is working (I think? Unless there's a seperate Hall Effect sensor for the injectors.) Throttle position sensor is working correctly, so it shouldn't be in "flood clear" mode.
What I suspect:
Either there's another condition that prevents the injectors from firing, like the "flood clear" mode that's currently active, or the ECM is jacked.
Has anyone encountered this before and/or could point me in the right direction? Thanks
 


RonD

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Unplug the TPS, that disable "clear flooded engine" for sure

So if you add fuel manually to the intake engine fires up and then dies, so spark is for sure working?

Only the exhaust side coil and spark plugs work when cranking, just FYI

CKP(crank position) sensor starts spark and fuel injectors.

CPS just helps fine tune sequential injection, engine will run without it.

It won't run without CKP sensor pulse, but you would have no spark either
 

bmostowy

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Thanks for the reply. If I unplug the TPS, I lose spark, which is strong & correctly timed otherwise. I checked the TPS at the connector with a wire probe, ranges from 1v to 4.5v as I understand it should, and yes, if I give it a shot of fuel it will fire & run for a second or two.
 

bmostowy

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Have good news and bad news: found the problem, but its not a cheap fix. Did a KOEO test (which I should have done first, & quite possibly violated the rules of this board for, in which case, I apologize & fully realize how stupid I look) that returned code 513: PCM failure. Looks like I'll be in the market for one of those. Thanks for the help, can a mod remove/ relocate this thread? Can't seem to do so on my own.
 
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RonD

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That may explain why unplugging the TPS killed the spark, because it shouldn't, TPS is not needed for engine to run, it would be sluggish but you could drive it.
 

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