[89k5]

O.K., on my fullsize 89 blazer, with 350TBI, 700R4, the brown wire with black tracer is under the hood. The wire is on the driver side, by the firewall, and there is about six inches of wire with a connector sticking out of the wiring loom that comes thru the firewall. I disconnected it and checked my timing, it was about 20 degrees advanced!!! I changed it to the factory stated 0 degrees, tightened the clamp, rechecked it, then shut it down. Disconnecting the wire made the check engine light come on while the engine was running, but after turning off the engine, reconnecting it, and starting it back up all was good. I lost the stumble at about 2800 RPM, but it has a slight cough leaving the stop light, sometimes. Thanks for the help guys.