Thread: setting timing

im having a hard time setting my timing on the distributor. when i use the timing gun and set it my car backfires in the airfilter? when i retard it most of the way it does not. what am i doing wrong? why would it backfire like that??. i used a digital timing gun, i set it to 0 and made the mark on the 3rd line which i belive is stock timing.

Well if you think about it it might backfire into intake if you advance it too far because the valve is not closed until sometime into the compression stroke. However if you are doing that when your timing appears to be stock or a small advance (10-15*) then it sort of seems like your pulley marks are not correctly on time. Is it possible for the pulley to be out of time but still have the cam and crank timing correct (as in it looks on time but it's really not)??

did u recently adjust your mechanical timing, or cam gears or camshafts

i did not adjust anything when i got the motor. I did have to swap some old belts but that wouldnt change my timing?

Here is what I can see happening: If your cam timing was retarded too much it would look like you were timed to say 15* but the intake valve could still be open thus causing the timing issue. But I don't see how it could be off if you never messed with the chain.

I highly doubt that you are backfired through the intake with simple distributer adjustment. I can almost guarantee that you have a mechanical timing issue. It has probably jumped timing... Pull your valve cover and look for the obvious

^ thats exactly what i was getting at, alot of the time if you adjust your timing all the way to one side and it runs better, then your mechancal timing is off somehow