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Tbi removal

jheat
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jheat New Member

jheat

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Hello this is my first post on here this is my 1988 chevy heavy half cheyenne has a 350 and a 700r4 when i got this truck it was known to have tbi issues and I've changed everything that I can think of and that the internet has said to make the injectors fire and they will not pulse the truck has great spark and is getting power to the injectors a full 12 volts and they will not pulse I'm looking for guidence and I've tried distrubtors I've tried different injectors I've tried ignition modules I've check that fuse for injectors I redid the words to the injectors and nothin changes. Again looking for anything that might help but if i can't think of anything what would be the best swap to from tbi for this truck 

IMG_0858.jpeg

jheat New Member

jheat

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Wires not words and whatever other typos I might have 

KARNUT Senior Enthusiast

KARNUT

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Posted
3 hours ago, jheat said:

Hello this is my first post on here this is my 1988 chevy heavy half cheyenne has a 350 and a 700r4 when i got this truck it was known to have tbi issues and I've changed everything that I can think of and that the internet has said to make the injectors fire and they will not pulse the truck has great spark and is getting power to the injectors a full 12 volts and they will not pulse I'm looking for guidence and I've tried distrubtors I've tried different injectors I've tried ignition modules I've check that fuse for injectors I redid the words to the injectors and nothin changes. Again looking for anything that might help but if i can't think of anything what would be the best swap to from tbi for this truck 

IMG_0858.jpeg

You didn’t mention anything about fuel pressure or checking the fuel pump. Check that.

jheat New Member

jheat

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Has a new fuel pump but no way to tes pressure 

richard wysong Senior Enthusiast

richard wysong

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Posted

Sounds like it may be the ECM. It's behind the glove box. Injectors are triggered by a ground pulse so check the input grounds to the ECM. Alldata and the factory service manual have detailed diagnostic trees to help you figure it out

jheat New Member

jheat

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I've followed a bible for these trucks and still no luck and I'm afraid that it might be th ecu is it hard to do if not how cheap is a ecu 

richard wysong Senior Enthusiast

richard wysong

Posted
Posted

Easy to do and not expensive. If you followed the "bible" you would know it's easy because to test the inputs and output requires removal so it sounds like you have been throwing parts at it rather than  following the diagnostic tree

 

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