dburgjohn

my 1981 is stock except for a high flow air cleaner and dual exhaust with glass pack mufflers. I get backfire in pipes during deceleration that I beleive is due to a lean condition.

how can I know what jet changes to make to balance the system?

tonyv123

I'd first make sure you don't have any vacuum leaks.. The computer should be able to adjust for the headers. Make sure the header gaskets aren't leaking, and check or replace your 02 sensor. Hope this helps, and let us know after you check these out.

dburgjohn

Not sure that gen computer can adjust that much. As i understand it controls only idle air mixture and timing advance. I have checked for exhaust leak and find none.

7t9l82

tail pipe poping is somewhat normal with glasspacks. rejeting could be necessary a free flowing exhaust will affect the a/f ratio. many times when people put headers on a car the performance doesn't improve until the air fuel mixture is corrected

tonyv123

dburgjohn,

Have you visited the '81 vette forum? http://www.corvetteactioncenter.com/...earchid=196249

They have alot of info about the '81 computer system. I just typed in header, computer in their search box and alot of info comes up.