I for the life of me can't get my timing set. I've had this problem before and since the weather is nice I can't ignore it any longer. When I hook up my timing light to the number one plug wire the timing shows way off. The only way to even get the timing light flash close to the timing mark is to put it on the number eight cylinder plug wire (90 deg. off). If I put the timing light back on the number one cylinder the mark on the timing light is set at the passenger side bank of cylinders (again, 90deg. off). I have never unplugged the black/tan wire (couldn't find it), does just unplugging the 4-wire connector that comes off the distributor work? Any help would be great. P.S. '86 Trans Am with 355 motor I built, carberated, did the same thing with 305, current motor with different blancer too).

 

no ecm controls? is the vacuum advance unpluged?

 

The distributor is stock, so I guess it's ecm controlled, not vaccum advance. It's always been hooked up when I adjust the timing, is that why I'm having problems, I wouldn't think it could change base timing that much, and how is the motor still running? I think I should have a little more power, it's not down that much I dont think, but then again, it's always been set-up like this, even with old motor.

 

also does unplugging the 4-wire connector coming off the distributor disable the ecm from advancing timing?

 

That's what you do for computer controlled carb cars. There is no "black/tan" wire (at least not for the ignition control).

 

Thanks, one questions answered, but can anyone help me with why ignition is so far off. Suggestion are more than welcome.

 

might not be the problem, but what is often wrong is:

your timing tab isn't correct for your balencer, or the outer ring on the balencer slipped.

in either case, TDC on the timing tab, and the TDC mark on the balencer doesn't accuratly show TDC.

the way to fix that is, pull the #1 plug wire, turn the engine over by hand, stick your finger in the plug hole, find true TDC, then either paint, or etch the correct mark on balencer where it lines up with the timing tab, or scratch a mark on the timing cover to line up with the mark on the balencer

 

thanks, I'll have to double check everything Saturday. I know the outer ring hasn't slipped, but the timing tab may be the wrong one.

 

Your timing advance at idle could be 20-29° beyond the base setting if the EST is active. If you have your base advance set at 6-10° (which is not unusual), the idle advance could therefore be approaching 40° BTDC. You need to disconnect/bypass the EST to set base timing. You'll also need to clear the error code you will generate in doing so, but after the timing is set. Remember to set the base timing with the engine hot, and at the specified RPM.

 

Thanks vader, sounds like what I needed to hear.

 

So, I had some time on my hands and went to try and adjusting my timing right for good, and it's set to were it works allright (just past the point were it's not pinging under-load) but, things is it makes no sense. I pulled the number one plug, got the engine to TDC after compression stroke, got the distributor pointing at the number one plug wire, buttoned it all back up and tried to start it. To make a real long story short, I had to adjust it way after TDC....way, way after, so far after that if I put my timing light on the number 8 plug wire that I have to adjust way past the timing tab marks to around 25 degrees to stop the pinging underload, doing the math that's around 65 degrees BEFORE TDC. Why is this happening!?!?!?!?!?!?!?! Also, I ran into a spot (way off what its set now) that it ran SUPER smooth, but idled at around 300 RPM. I never seen the engine run so smooth (has a 274 cam), it ran as smooth as an electric motor, with almost no rpms, I was afraid to rev it, and knew it couldn't be right (could it be?), just why did this happen? How could it be so smooth and slow?

 

Have you done anything with the cam and/or timing set recently?

 

When I built the motor in July-August. Also changed the changed the balancer after that. I always had just set the timing by ear because I didn't understand this problem (hence the neglect). I just can't go without understanding this problem any longer. I edited the last post, please read it again, thanks for all the help.