Injectors aren't injecting
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Joined: Jan 2020
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Injectors aren't injecting
90 f150, got spark, 50lb fuel pressure at the rail, fire to the injectors, but fuel not injecting. I can make the truck run injecting fuel into the throttle body with a squirt bottle. Something not letting these work. Any ideas?
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Joined: Jun 2004
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Well, the ignition system is what the computer uses to time injector firing. Since you've got spark, the ignition system should be working - at least well enough to run.
Now, since the injectors are fired in two batches (of three injectors) a broken ground wire would only disable three injectors and not all six. It's more likely one of the ignition signal wires is broken on the way to the computer, the computer has a bad power or ground wire, or the new computer is bad/misboxed, something.
If you pull the computer connector:
Power should be on pin 1 (Key On)
Ground should be on pins 20, 40, 60
From the distributor module:
Gy/Or PIP signal on pin 56
Pink Spout signal on pin 36
Or/Red ground on pin 16
Now, since the injectors are fired in two batches (of three injectors) a broken ground wire would only disable three injectors and not all six. It's more likely one of the ignition signal wires is broken on the way to the computer, the computer has a bad power or ground wire, or the new computer is bad/misboxed, something.
If you pull the computer connector:
Power should be on pin 1 (Key On)
Ground should be on pins 20, 40, 60
From the distributor module:
Gy/Or PIP signal on pin 56
Pink Spout signal on pin 36
Or/Red ground on pin 16
4wd Low
Joined: Jan 2020
Posts: 11
Likes: 3
From: Alberta
I had the same problem with an ‘87 F250 and I think it was similar to what mary_kate alluded too. What I found was that there was One lead on the back side of the ECM board that had corroded or burned out. So I took a real light gauge wire and soldered it across and that was what fixed it.
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