Question: Timing my 81

[Dunzvett81]

I am in the process of giving my 81 a tune up. I am just not sure about timing an 81 seeing how it has the CCC which controls the advance timing. I am use to the older distributers that have the little canister with a hose connected to it being the vacuum advance. However, with the 81 I can't seem to find one (only electrical wires) Does anyone know what I have to unhook if anything so I can get the base timing. :confused I believe it is 6 degress BTDC. thanks

 

[Sensei]

Disconnect the 4 pin connector at the distributor and set the timing at 14 BTDC. 6 before is for emissions stuff and you get much better performance and fuel economy at 14. If you get detonation, the computer will retard the ignition and avoid damage. If that happens you may need to go to 12 before or run premium fuel. I run 14 BTDC and a Hypertech performance chip with premium fuel. God bless, Sensei

 

[Dunzvett81]

Thank you Sensei, appreciate the help.
Jay

 

[Dunzvett81]

Please help!!

I removed the 4 pin connector and then put the timing light on.
PROBLEM: The notch in the balancer is no where near the timing marks. I can see the notch and it is away from the timing marks on the driver's side about midway down on the driver's side. What am I doing wrong?

 

[Sensei]

Check to be sure you are on the #1 wire.

 

[GerryLP]

Make sure that you are on the correct phase (8 cylinders ;on the gun), and if you have those up and down arrows to manipulate the timing, then go either up or down -whichever way it gets the marker to move up to the timing tab. Also,like Chris said, make sure that you are on the #1 lead.

Make sure you do not adjust timing while the transmission is on "D" or drive.

GerryLP:cool

 

[Dunzvett81]

I am on the first wire (the plug on driver side closest to front; marked on manifold as 1) Gerry, I am not sure what you mean; I have no settings on my gun.

 

[Sensei]

Could you just be that far off? Move your distributor around and see if you can get it in range.

 

[Dunzvett81]

Know here is the funny part! The engine actually runs and idles really nice, no missing. In gear I will notice a slight miss, but overall not bad. So I can't figure this out. If I can describe the top of the dist. it is sitting with the top long piece where there is wires 90 deg. to the windshield. I thought about just turning it but I am affraid I will really mess something up.

 

[GerryLP]

Jay,

With the engine OFF, see if you can turn (by hand) the vibration dampener/torsional balancer. Perhaps the thick rubber ring on which the marker is located has shifted.

GerryLP:cool

 

[21Again]

Picture of the 4-Wire ECM Connector

Here's a picture of the ECM connector you should be disconnecting. Notice the wires come from the rear of the distributor.

 

[Sensei]

Did you ever get this figured out?

 

[Dunzvett81]

No I didn't. Don't know what to do. very strange.

 

[schweng18]

I had this exact issue with mine. The remedy was to replace the vibration damper, It is a common problem with the small block Chevy engine. With age the rubber gets hard and the damper slips causing the timing mark to move. My problems were resolved after changing the damper, the timing mark lined up correctly and the slight stumble the engine had dissappeared.

 

[Dunzvett81]

Well....... all is good now. I replaced the harmonic balancer, it was slipping!! also have new camshaft, lifters and timing chain. She runs like a new car!!

 

[GerryLP]

I am glad, Jay. Maybe there will be enough time left in the summer to get her on the freeway for a trip somewhere. Congrats!

GerryLP:cool