I've been trying to set the timing on my 1987 camaro 305 Lg4 . I could never set the timing with the origonal dampner. So I replaced the dampner and installed a new timing chain. Engine runs but still couldn't set timing. Then I exchanged the new dampner for another one at the parts store. Same problem. I've even tried putting the old dampner on. I've checked and specified that the timing cover was in the 12 oclock position. I've disconnected the 4 wire connector at the distributor to set base timing at 0* tdc. But the engine will only run at about 40 degrees ahead of the 12 degree mark on the timing tab. in other words, the engine only runs when the mark on the dampner is under the passanger side under the water pump (way far off). I've even replaced the distributor and it is still doing the same thing. I've pulled the timing cover off and rechecked the alignment of the timing marks. No slack in the chain, it is a cloyes type. Could a mis aligned timing chain cause the misaligned timing mark on the dampner?

BTW. I really need to smog the car so I can sell it I bought it two years ago thinking I would restore it but don't have the time or money for two cars.

Thanks.

 

You probably don't have the right damper. One type has the timing tab TDC right about 12 o'clock, the other is about 1:30 o'clock (another is about 2 o'clock).

 

It's under the PASSENGER side arm of the water pump? Man, that's WAY far out. Not just a balancer mixup issue. The timing tab might be in the wrong place for the balancer you are using but at TDC the line should either be straight up behind the water pump or over in about the 1:30 postion towards the driver's side. Never on the passenger side.

Timing chain is not an issue. Has nothing to do with the location of the balancer pointer vs. true TDC. Balancer is keyed directly to the crank.

Just a wild guess here, and I don't mean to insult you, but you are putting the timing light's pickup on the #1 plug wire, right? That would be driver's side front spark plug.

I'm guessing that you've confirmed positively that the 4-wire connector you unplugged is actually the timing connector, right? Even at idle the stock ECM programming will be throwing in quite a bit of additional timing over the baseline setting.

Also, make sure there aren't 2 lines scribed into the balancer. Might be a second line that is not as noticable but might be the right one to use for timing.

Beyond that I'd have to recommend you check the position of the keyway in the crank. It should point directly at #1 TDC (45* to the driver's side of stright up) when #1 piston is truly at TDC. This keyway position never changes regardless of year/model/engine size or balancer style. This is always true on all SBCs. If yours doesn't point that way then I suppose it's possible that the crank is manufactured incorrectly or that the ZZ3 uses a crank that has to have a matching balancer that only works on that crank.

 

Thanks for responding,

This is my Camaro with the 305, not the Trans Am zz3

used the inductive clamp on the number 1 cylinder wire on the first cylinder front of car driver side. Checked it was ok.

Verified the firing order 18436572

The crank Keyway lines up at 45* inline with the cylinder like it should.

each new balancer I've tried has the keyway at 45* and one timing groove at 12:00

origonal timing tab welded up at the 12:00 position. this was OEM on LG4 305's right?


I really dont know what else it could be

 

Did you disconnect the ECM distributor wire/harness when you checked the timing?

 

Yeah, the LG4's had the timing tab behind the water pump in the 12:00 position, about 45* CCW from the position of the keyway. If the balancer was for a 1:30 position tab the timing mark would be offset only about 10* CCW from the keyway.