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Ask Chad Farhat Your Own Question
Chad Farhat
Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems
Category: Chevy
Satisfied Customers: 3654
Experience:  Owner at Carolina Auto Service & Sales , 20 years Experience in Foreign & Domestic vehicles A6 - Electrical / Electronic systems A7 Heating / Air Conditioning systems
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I have a1987 chevy corvette with no pulse on injectors. I

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I have a1987 chevy corvette with no pulse on injectors. I can't find the Obd1 connector so no codes are available. I see12v on both sides of injector connection, thinking on a bad pcm or short to power. Please help

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

This is the wiring circuit for the fuel injectors , the injector are pulsed by the ECM

The fuel injector is solenoid operated and ECM controlled. The ECM energizes the solenoid, which opens a valve, allowing fuel delivery. The fuel, which is stored under pressure in the fuel rail, is injected in a conical spray pattern into the intake manifold near the intake valve, Fig. 3.


If you do not mind me asking ,are you looking at fixing this yourself or looking to know the most possible cause of this issue and taking it to repair shop for the work ?

Do you have any prior experience in electrical troubleshooting and testing with a test light for power & ground ?

Do you have a test light & or power probe for testing ?

Please let me know

Thank You

Chad Farhat

ASE Certified Technician

Customer: replied 2 months ago.
I do have some experience on mechanics and electrical issues as well. Is it normal to see voltage on both sides of an injector connector? It has to be ground pulses from the pcm right??

IF you see voltage on both side it means ,we are missing a ground , most like the computer or wiring to it

inspect the injector wire back to the computer

where you able to see the wiring diagrams

Please let me know and we can work on it ,this requires some testing and might require some back and forth with me here

Thank You

Chad Farhat

ASE Certified Technician

Customer: replied 2 months ago.
I started checking the car, sorry for not been in contact till now. I'm seeing good spark when cranking but no injector pulse. I disconnect all injector connector to check one by one and started checking with a light tester and adding ground or just touching the wire back and forward so I can see a pulse, by doing this I did see the pulse but when I connect all the wires back I don't see that pulse. Why??

oh no worries i understand ,

Yes but that tell me the pulse from PCM is bad ,most likely is the pcm is bad, do a continuity test on the injector wires back to the pcm ,if they pass change the pcm

let me know


Chad Farhat and 4 other Chevy Specialists are ready to help you
Customer: replied 1 month ago.
Thank you, ***** ***** check that and let you know
Ok sounds good
Keep me updated