93 Suburban Dies When Put in Gear...Then Doesn't...

[dstoddar]

93 Suburban (350) wouldn't run, so I followed a lot of the threads in this forum...got it running by:

Replacing Ignition Coil
Replacing ICU
Replacing Pickup Coil

Then I put it back together, ran, but died when I put it in gear.

Inadvertently, I figured out how to fix it. I unplugged the brown wire under the plastic cover on the firewall (the wire you unplug to time it), left it unplugged, and the truck runs great (doesn't die when I put it in gear).

Anyway, I left the wire unplugged and all seems great. What does this wire do? Why when I plug it in does it make the truck idle differently and die when I put it in gear? What is causing this?

Thanks!

Damon

[planedude]

that plug puts the truck back to base timing, I would say you should set up your timing again either that you may have a computer issue.

[dstoddar]

Which notch is 0 degrees? I can't tell from looking at it...

[planedude]

I'm not 100% sure but I think its the middle one.

[back2life]

go to the mark on the balancer and on the timing scale clean them or put some chalk on them and youll be able to see them

[dstoddar]

Originally Posted by back2life

go to the mark on the balancer and on the timing scale clean them or put some chalk on them and youll be able to see them

I can see the marks, just don't know which one is 0 Degrees!!

[back2life]

when facing the front of the engine, the farthest to the right there is a point on the timing scale that is pointing to you that is nothing, immediately to the left of that is an indentation pointing to the engine- this is the 0 degree mark your looking for. going farther to the left mark after mark is 4,6,8 degrees. engine needs to be warmed up at idle and the timing advance plug needs to be disconnected