TheBradyBunch

I bought a 1985 Trans Am with the 305 tpi. It is the first time I have actually worked on an engine and I am having some troubles. I did some work on this car with my buddy before I bought it from him and noticed he had no clue what he was doing. He told me that he had replaced all of the intake manifold gaskets at one point and there was a massive vacuum leak after he did that. I took the intake completely apart and noticed that most of the bolts could easily be taken off by hand, as well as 5 of the 8 spark plugs. So I redid the gaskets from the lower intake manifold all the way up. In the process, I forgot to mark the distributer, and ended up redoing the timing. I set the #1 cylinder to 6 degrees btdc and plugged in the wires in the right firing order. The problem I'm having now, is that it will not start. I did get it to start once off of starting fluid, but never idling, I had to keep on the gas to keep it running. It sounded like the timing was off and like it was trying to backfire. The distributer cap has to be screwed in, so I can't just rotate it to advance/retard the timing (that I know of) and I'm honestly not sure what to do next. Any suggestions would be greatly appreciated.

Reddragon88gta

Just a shot in the dark but after pulling the distributor and re-installing it I wonder if you are 180 out? I’ve heard that can cause the backfiring and it makes sense as you were running before pulling distributor.

You should be able to twist the distributor to adjust base timing once it’s seated as long as the distributor hold down isn’t too tight. A flex head ratcheting wrench or distributor wrench work well. Did you unplug the EST bypass to set base timing? I didn’t see you mention it.

stew'86MCSS396

I don't know why people find it necessary to mess with the color of the fonts...
Assuming that's the^^^issue...

Since the timing set gears are at a 2:1 ratio, the crank needs to rotate 2 full revolutions in order for the camshaft/distributor to complete 1 full rotation hence you could be 180 out.
You could possibly rotate the engine until the mark on the balancer is at TDC then remove the distributor cap to see which plug wire the rotor is pointing at. Once you establish that it's pointing at 1 or 6, you can do 1 of 2 things...pull the distributor, rotate crank 1 full revolution aligning the balancer with TDC and re-stab distributor at 1 or 6 depending on which cylinder you started with or pull the distributor just enough that the distributor gear disengages with the camshaft gear allowing rotor to turn freely and then attempt to re-stab it rotor pointing at the opposite cylinder.

Vader

Wow. That photo has really made the rounds in the last 20+ years. I guess it's worth more than a thousand words, as they say.

You might as well show the "before" photo of the twin bicycle chain timing set:

Vader

The point of that is that the distributor could be 180° (360° crank rotation) out of phase, or could be just a tooth or two off, resulting in 30-70° out of the intended position.

MikeKy

Bring number one cylinder up on TDC, pull the cap and be sure the rotor is pointing to number 1 cylinder and make sure the plug wires are in the correct order in the cap.

TransamGTA350

iTrader: (2)

This...and then also leave the distributor clamp loose enough that you can turn the distributor by hand. While cranking it over, you may need a friend to turn the distributor a little one way or the other to get it to fire up and idle. Then, you can set the base timing with a timing light.