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73-87 Chevy _ GMC Trucks => Fuel Systems and Drivability => Topic started by: catbird7 on July 14, 2025, 05:56:24 pm

Title: No Start TBI
Post by: catbird7 on July 14, 2025, 05:56:24 pm

1987 R10 305 4spd manual 4x4. No pulse to injectors. So far I have purchased new fuel pump, new fuel filter, new fuel pump relay, completely new distributor, and new computer. Verified power at both ecm fuses and verified the fuses are good. Overriding the relay, forces the fuel pump to run and provides fuel pressure at the injectors however will not spray. 9 volt battery applied to injectors produces good spray  from both injectors and allows the engine to run but only until the initial sprayed fuel is burnt. I have no check engine light at all, and I pulled the instrument panel apart and verified the actual bulb for check engine light is good. I'm lost!

Title: Re: No Start TBI
Post by: VileZambonie on July 14, 2025, 07:12:59 pm

http://forum.73-87chevytrucks.com/smforum/index.php?topic=37738.0

If you are certain ECM B has power in and out of the fuse, check at the two cavities at the ECM as seen in the link I posted.

Title: Re: No Start TBI
Post by: catbird7 on July 15, 2025, 07:07:28 am

Explain, "two cavities at the ecm"? You need to dumb this down for me.

Title: Re: No Start TBI
Post by: VileZambonie on July 15, 2025, 01:43:50 pm

Did you click the link?

Title: Re: No Start TBI
Post by: catbird7 on July 15, 2025, 05:05:33 pm

Yep, guess I'm sub 100.............

Title: Re: No Start TBI
Post by: VileZambonie on July 15, 2025, 07:30:32 pm

Follow the flow chart and study the diagram. Check the pinouts at the ECM if all 3 fuses have B+ on each side of the fuse. I am attaching the connector views for you.

Title: Re: No Start TBI
Post by: Captkaos on July 17, 2025, 08:45:59 am

Quote from: catbird7 on July 15, 2025, 05:05:33 pm

Yep, guess I'm sub 100.............

?  Sub 100?  What do you mean?  Are you not able to get to that link?

Title: Re: No Start TBI
Post by: catbird7 on July 19, 2025, 06:20:45 am

Sarcastically making fun of myself "sub 100", meaning an IQ less than 100 which is considered average. When it comes to electrical issues I'm lost, therefore providing a schematic to me is about as useful as providing directions in Latin.

Title: Re: No Start TBI
Post by: VileZambonie on July 19, 2025, 08:00:10 am

Don't give up before you begin. It is not difficult, you just haven't tried to learn how to read them then. The last image shows you the backside of the connectors at the ECM. You can print the diagrams and use a highlighter to trace the wires you are checking.

Title: Re: No Start TBI
Post by: Captkaos on July 21, 2025, 03:15:57 pm

Ditto on the above.  I HATE wiring, Sadly I wired a LS engine into my daughters 2011 Mustang..  don't give up just ask.  Here to help.