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Diagnostic Plug In

gbrew

Contributor
Jr. Member
Joined
Aug 28, 2015
Messages
141
It's been a while but I'm back. Getting closer to finishing but I have a question about my diagnostic plug in. I have a 77 with a 99 rebuilt 5.0. The harness was reworked by the EFI guy and works great. Motor starts but I've not been able to drive it more than just in the parking lot so far.
1 It seems to be running pretty rich at idle.
2 Diagnostic plug in has no power to it. When I connect my tool to it nothing lights up on the tool like it usually does.
As usual any help is greatly appreciated and thanks in advance.

GB
 

darkmagus

Full Member
Joined
Mar 5, 2007
Messages
267
Also make sure your o2 sensors aren’t backwards. I had mine switched when I first fired it up and it ran super rich.

And I guess I should clarify, I got the wiring to the sensors backwards. Probably not as likely since Garry did your harness.
 
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