tbi no injector pulse 1989 k1500

[Mathies]

hey guys

after buying a new ecm a lot of the problems where solved but one the injectors doesnt spray fuel.
i already diagnosed a little.
- i have spark in al 8 cill
- the ecm recieves 12V to D14 and D16
- the injectors have 1.5ohm wich is above 1.2
- when connecting test light to injector connector and cranking the light doesnt blink
- the test light also doesnt blink when connecting 12V to crkt 430 (reff from icm)
- the test light blinks if i connect injector connector +side to ground.
- when turning ignition on i can hear the fuel pump buzz for 2 sec
- no trouble codes stored when bypassing aldl flickers code 12 three times
- also the coil, icm, distributor, pickup coil are all new.
- when using start pilot the truck runs till i stop spraying

chart a-4 says i have a short to voltage on the green and blue wire from the injectors to ecm.
i meussured continuety between those wires and ground but no continuety.

im a bit lost now. anybody that has had this problem or know what i could do more to diagnose the no injector pulse.

all help is greatly apreciated

 

[PlayingWithTBI]

after buying a new ecm a lot of the problems where solved but one the injectors doesnt spray fuel.

Did you mean "one of the injectors doesn't spray fuel" or both don't?

the ecm recieves 12V to D14 and D16

It receives voltage through the injectors. The ECM momentarily grounds those wires to fire the injectors. They are fed constant 12V when key is in run or start position.

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when connecting test light to injector connector and cranking the light doesnt blink

Is that a regular test light or a Noid light? You really need one to troubleshoot injectors.

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If the ECM doesn't see any DRPs (Distributor Reference Pulses) it won't fire the injectors.

 

[jigsaw]

If only one is spraying try hitting the one not spraging with something giving it a few taps as someone cranks it over see if gets unstuck

 

[Mathies]

I meant both injectors dont pulse and it was with a normal test light. Should i buy a noid light and test everything again?

Okay ill try hitting it gently when cranking but wont think it wil solve bcs the ecm doesnt ground the ecm.

 

[Mathies]

I also tested the injectors with a litlle 9V batt when i connected the batt to injectors for a very short time i could here the injectors work but no spray does this rule out the injectors are faulty?

 

[PlayingWithTBI]

Should i buy a noid light and test everything again?

Yes

I also tested the injectors with a litlle 9V batt when i connected the batt to injectors for a very short time i could here the injectors work but no spray does this rule out the injectors are faulty?

Maybe

 

[Mathies]

Bcs of the lpg that was in my truck i needed to reconnect the injectors wires. I did it this way is has zero resistance but coud it be the ecm cant ground it fast enough bcs of this? And okay ill buy that noid light. Hopefully it wil come quick bcs i moved and my truck has to be out of here by the end of the week

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[Mathies]

Is there any other way to test it bcs the noid light is out of stock and they prolly wont have in a shop nearby

 

[Schurkey]

An LED test light should work if it's connected across the two wires of each injector harness like a 'noid light would be.

Engine has spark, therefore the distributor pickup coil is good. I don't think it can be an ignition module problem, either. ECM or wire-harness seems most likely if there's power to the injectors but no grounding to make them squirt.

 

[Mathies]

Okay ill test with a led light if i cant get my hands on a noid light.

And could it be the prom mem call then bcs i bought a new ecm.