Timing Advance Without Chip Mod

[King]

A friend of mine passed on a performance mod that sounds interesting: A friend of his advanced the timing on his 95 350 ? ton ?burban by disconnecting a single wire (his was light brown w/dark brown stripe) from the distributor (a disconnect plug for maintenance) to the PCM, advancing the distributor by about 4 degrees and re-connecting the single lead wire. On his return trip from his friends, he saw a considerable MPG increase (not logged) and performance gain as well. Reportedly, his friend has done the same thing on his S-10 and ?02 5.3 Suburban. I haven?t had a chance to track the wires to the computer but thought I?d pass this on for further investigation.

 

[Navy_Z66_AV]

any others try this mod? i would like more info on this before i go disconnecting any leads. Also detailed info would be great. Thanks for the Mod tips though!

 

[flynhigh]

I was under the impression our 5.3 are distributorless SO I do not know how he could have made that change to a '02 Suburban

there was no reference to a distributor in the owners manual either.

 

[King]

I'm trying to get some more info but thought I'd give you what I have as a starter.

John

 

[KenHicks]

Yes that is true to set the timing on vehicles with ODB 1 you disconnent that one wire. They still had a mechanical distributer to turn and mechanically set. Dicsonnecting the wire disabled the computer and allowed the mechanical adjustment. However even on those vehicles you shouldn't leave it disconnected as timing needs to be varied depending on many factors...of which the computer handles.

To the best of my knowledge this is no longer true with any vehicle with ODB 2. Reprogramming the timing curve/conditions via an aftermarket PROM writer in the only way.

 

[King]

Ken -- Not what I was hoping to hear but sounds like you got the facts. Thanks -- John