Timing Effect?

[Rufus1050]

Good Evening all you motorheads...no disrespect intended, ok? Just finished browsing some of the threads and decided to put one up myself. While I was busy tinkering with my motor, the wiring jacket that encases some sort of fuse on the brown wire leading to the distributor was partially melted. Since you're suppose to disconnect this wire before you check the timing, I find myself in a pickle...I am afraid to cut the wire and splice in a new one at present. Any advice from you guys? I wonder if this could have an effect on the timing? It's not burned through, just melted real bad. The motor has a slight miss when you jab the throttle...puts me in mind of a fouled plug or perhaps a bad injector. I've pulled the plugs and checked and cleaned them. What's up?

 

[redc4corvette]

If the wire is burnt I would repair it no big deal it is not a resistor wire It is the est wire.The ingine miss on your year I have usualy found is the EGR valve if all other factors are operating .

 

[WhalePirot]

EST is the elecronic spark timing, from the ECM, which is why it is disconnected while setting the timing. THe ECM will retard timing, for example, if the knock sensor 'hears' knocking. BTW, I have heard of knock sensors 'thinking' other sounds were knocks, doing its thing, even though the sounds were from elsewhere. Retarded timing reduces performance.


You might want to know why the wire melted. Was the heat from excessive current draw or from external heating? Careful examination should clue you in, especially if the melt is over a wide area, perhaps flattened and more on one side, or if it runs the length (internal heat). Try to use the same color wire and ensure you use the same gage of wire.

 

[Hrtbeat1]

Also check the wiring harness inside the distributor that you're harness plugs into. There is a ground wire that will sometimes go bad and cause the same rough running symptoms. These cars are 15 - 20 yrs old and sometimes .... most of the time, the wiring is just about shot. If you have the facilities it's not too tough to fix.

 

[Rufus1050]

Thanks for all the input CAC!!! I cut to the chase and spliced the wires after cutting out the melted connector...it was lying on the header pipe...with some quick connects. Put my timing light on it and set it 8 or 10 BTC and it runs like a kitten. The timing was at 0 degrees...no hesitation; runs like a charm. Now I'll move on to my winter project...replacing the bushings with polyurethane set. Happy New Years to all my little buddies in Corvette Land!!!!!!!