ok, is not on my car, is a friend of mine that have a completelly stock 85 GSL has over 160K on and is running real ruff. first. last sat i was helping him to fix a fuel leak on his carb because it was leaking from the accelerator pump, but before that it was running a little ruff. well we fix that and now is running real ruff and i notice that the cats were hotter that what it should and we replace those with ones i had at my house but it got worse and what it does is in idle it revs up and down and backfires and when deaccelerating it backfires too and it smell real rich. but driving down the road it fells smoth i think is the carb but im not quiet sure because the car was sitting for like 2 years so i dont know and before he started it up he did the tuneup on it (cap, rotor, spark plugs, ect ect ect). i dont know much about nikki carbs ethier so im just learing by the minute. and i search too and i couldnt find anythging that could help me too. so last thing im gonna do is check compression to see if it that . so can somebody can give me some help for what to check other that compression? sterling or somebody thanks

 

it probably is rich...why would you think otherwise?

it had a fuel leak. fixing it got more fuel to the engine, correct? so it was set at a particular amount, but compensating for the loss throug the leak. so now it gets more than before.

so it's running rich. that's probably causing all of your problems. idling rough, backfiring, and clogging cats sound to me like running rich problems.

check compression, and tune the carburetor. That would be my guess.

I had a old Prelude with dual carbs...one decided to go out, dumping fuel. Ran really good past idle, but it stalled at lights, got 13mpg, smoked, and clogged the cat. Had the carbs rebuilt, got 26mpg, idled smooth, etc. So that's why I say what I do. It was a pain setting the idle because it was a single setting for both carbs. One worked good, the other was just dumping. So 2 cylinders got a lot, the other got who knows how much.