Hi, ok my car is still popping though the exhaust, only on decel, I can rev it all day and never get a pop, I have replaced the headers they where leaking, I have tried a rebuild carb and jet perf carb and it is still doing. I have tried ahollow cat a straight pipe and it is still doing it. The car runs great except or this and it is driving me crazy, I have been chasing it for years and have spent alot of money.Any ideas?
tps egr could they have affect?
The car has a small leak at the muffler, but is small (I hooked it up to a smoke machine that is how I found that but everything else is leak free) please help.

 

I have tried a hollow cat, a straight pipe and a new cat, so it is not that.

I do not have a vac advanced it is computer controled carb and dist.

How do you tune the carb? all of the settings are right, could you please tell me what to do. .
I was thinking about playing with the timeing what do you thing?
what about the tps?
how do i get the car to be less rich on decel?
It does not do it right away after I let off the gas it takes a few sec on decl, usaly when teh rpm drop beloww 2,500/3,000 somewhere in that area, if i just touch the gas pedal a little bit it goes away. Thanks
thanks.

 

If it was my vehicle I would get rid of that CCC carb and distributor and either upgrade to a full EFI system or get an Edelbrock carb and good old fashion HEI distributor. But that is just my .

 

have you checked your firing order ??? i had it happen to me before where it was one off and it ran but when you hit the gas and let off it spit back thru the carb

 

It is not the firing orde the car runs great and the backfire is though the exhaust.

 

Are you sure there's not a crack in the muffler.

 

Yes I am.

 

do you have headers ??? if so could be a bad collector gasket at the head or flange

 

I disconected the 4 wire conector at the dist (the used to set timing) and the car does not pop on decel nearly as much, so what can I do now?timing chip? please fill me in? thanks

 

sounds like your timing is out of whack may be a tooth off did u pull the distributor or do a timing chain recently? if so i would bring the motor to tdc and redrop the dist see if that helps cause it sounds like your a hair off

 

from what i have read,i agree.your timming sounds off a tooth

 

The car runs to good to be off a tooth.

 

it can still be off a tooth and run ok,but when you drive it and stuff it will spit and studder

 

if all else fails pull the valve covers. turn the engine and watch the rockers. if one appers not to have the lift that the others do a worn cam lobe or lifter could be the culprit. i hope that isnt your pboblem

 

prob lean condition on decel

 

The guy that told me to disconect teh est 4 wire connector said since that fixed it most likely the car is to advanced on decel, he said that the vacum sensor on the drivers side firewall maynot be working right, he said it should have manifold vqac which it does it is hooked to a fitting right behind the carb (it goes in to teh manifold.
Any ideas? thanks

P.S some people say lean on decel others say rich on decel? which is it?

 

I have the cc carb and dist, could I make some kind of switch that would cut the circuit to the est when the throttle is closed?

what about teh l69 chip, could i get one of them and stick it in my stock ecm? if so what part number do i want? I have a knock sensor and a 5 speed.

Or should I just go with a none cc carb and dist? if so which ones and what do I with all the other sensors and the ecm? thanks

 

how about only using one thread for the same problem so people dont have to read both to get all the information

 

first thing is first tune up, then go from there. good chance it a lean condition

 

The tune is good the af meter said the a/f is good.

 

do you have the stock AIR system? if so the anti-backfire valve or diverter valve could be bad. carbs in working order should always run ruch on decel.

 

nope air system is gone.