I have been having this timing issue with my 85 Trans am. Originally it had a 305 with the ccc carb. I swapped the 305 for a 350. I can get the car to run but when I put a timing light on it it looks to be 45 degrees off. I have the right timing cover and balancer on it. I cheched that several times by finding number one cylinders top dead center and making sure it lined up with the timing mark on the cover. Has anyone else seen this before? As I said the car seems to run well like this but it makes it hard to set the base timing.

 

Maybe your mark on the balancer is off.
Bring the motor to TDC, put in a piston stop. Turn all the way closewise, mark the balancer. Turn all the way counter clock wise and mark the balancer. Find the center and you have true TDC. Over the years old balancers twist a little.

 

Its a new balancer. I have already done that. I am starting to wonder if the valves are mis adjusted or my timing light has gone bad. I forgot to say that it is 45 degrees advanced. the rotor is almost pointing to cylinder number two.

 

Bring it to TDC and put the distributor back in then attempt to point it as close to #1 as possible. If it seats before or after #1 your timing is likely off.
It truely doesn't matter where it points as long as the #1 wire is plugged on top of that point.

Other than that your valve timing is way out from an improperly degreed/installed/defective cam or your timing light took a crap.

I don't know if a 45 degree advanced motor at idle would even fire up without a super high torque starter.


Just to double check, 45* at idle, vacuum advance plugged? Do you have springs on the weights underneath? It's possible they fell off but I can't see that firing up.

 

If it RUNS good, it IS good.

The engine does not whup out a "light" and a "book" and examine the "mark", and decide how it's going to run accordingly. All it cares, is when the spark occurs; the "mark" doesn't bother it in the least.

Forget about the marks. Or, if you just have to have one that lines up with something somehow at sometime, make one.

 

Did you unplug the Brown Wire to set the timing?

 

I was going to say this sounds like the classic "balancer/timing tab mismatch" (which puts you off about 35*) but you say you positively verified TDC on the tab agrees with true TDC. So that's out as an explanation, I guess.

That leave only the timing advance at idle (must disconnect the ECM plug at the back of the distributor to properly set base timing, if it's still using the factory cc-HEI). If it's not the cc-HEI are you disconnecting the vacuum advance before you set your base timing?

 

This is the factory ccc HEI. I have unpluged the connector on the back of the HEI, as the book says, the same way I always did when the 305 was in it. It doesn't change anything. This doesn't seem to be to big of a problem when the car is running but it makes it really hard to start. I have already cracked one starter housing when it tried to fire too soon.

 

Not sure if those have vacuum advance.. but if they do, you are checking base timing with it capped off right?

 

There is no vaccuum advance on a stock distributor. Have you tried backing the timing down to agree with the mark? If you're breaking starters, you might justbe too far advanced. I've never heard of a car running very well at 45* advacedbase timing though.

 

Finally found the problem. I had installed a defective ignition control module [ the one under the cap ] replaced it with another one and was able to time the engine. Thanks to everyone for their help and input.