If the exhaust thing does'nt work. Look at the distributor again and its advancement. Timing. One of two degrees can make a difference. The float lever needs to be set first. This should have been done anyway. Good luck.

 

yeah, I guess I just bought into the "Preset" theory. Lesson learned. So I will do that and then screw with the timing. I will start low and work my way up till it settles in.

 

I feel your pain, I have chased cats for about two weeks with an timing issue. Popping thru the exhaust at idle. Aftermessing with the A/F's, I finally adjusted the timing in the ECM at idle, and it now purs like a kitten. ManwasIdumb.I also have bought into the preset theory, on the floats, haven't found one to be right yet. Let us know what solves this, asit helps us all learn.

 

The floats were correct. I used a drill bit to measure, and they are right on the money. In about an hour I am taking back to the shop that did the exhaust and have them check it. Since I posted the last time, I have also changed out the gasket between the collector and reducer. It was not in that bad of shape, and there is not any rust on the headers or other exhaust parts. I thought there was. So we will see what the shop says about it.

 

if you still have air injection, its a classic case of a bad diverter valve. (allows fresh air into the exhaust manifold during decel if bad).

 

Just got back from the shop, no leak. So I have no clue. Also, the mechanic told me that maybe my valves may just have carbon on them, and maybe that could cause backfire. He said that he dumped a little water into the carb to burn it off??? Is that one of those little tricks of the trade that I am just to green to know? He also said tranny fluid would do the same thing if dumped into the carb.

 

I wouldnt put water in the carb.But the thing with tranny fluid is a just a cap full or so in with the oil and let it burn everything off then drain the oil.

 

Yeah, misting water into the venturi of the carb will burn off all the carbon deposits that have collected on top of your pistons and your valves. That mechanic sounds like he knows his stuff regarding old carbureted engines.

 

He seemed to. I was a little leary at first, so I drove it about 15 miles afterward, both city and highway, and I didnt notice any negative effects (nor any real positive ones either). But it did not cure the backfire[:@][:@]