Corto

Hi,
are there any difference between Q-jet '80 and '81?
I have a chance to get one rebuilt '81 Q-jet that i would use on my '80 C3, and I am wondering if the Q-jet has been changed as a part of L48-->L81?
Thanks
Corto

Yeller81USNRet

The 81 is a E4me carb Computer controlled. Very basic computer control. I don't think it will work correctly on a 80. Some with more knowledge will comment I am sure.

TedH

Agree. '80 was the last year for non-computer carb on a 350ci engine in the vette (L48 and L82). Only thing electric on the carb was the electric choke.

I can't speak to the LG4 (305ci) offered only in Kalifornia (sic)...

350ci from 81-85+ (from my memory):
'81 was the computer carb (L81)
'82 & '84 throttle-body injection
'85+ tuned port injection (L98).

Shark Racer

The 80 California carb is an E4ME which have slightly different connectors than the 81 E4MEs, but are functionally the same.

If the OP's 1980 is a California car, the 81 carburetor could be used but he would have to switch to newer-style pigtails.

7T1vette

Agreed. An '80 car built for CA would have had the electronic carb. The other 49 states just had the standard Q-Jet in 1980. The '80 CA car and '81 car had the electronic carb that interconnected with the distributor, O2 sensor, and ECU to allow real-time adjustment of timing and fuel ratio. It was an early computer controlled system, but was better than a standard carb (unless tuned well by a knowledgeable mechanic).

Corto

Ok, thanks for the info, it is 49 states car.

Shark Racer

FWIW the 80 CA/LG-4 vettes did NOT have a computer controlled distributor - carb only. Distributor is the same as 75-79 - HEI with mechanical and vacuum advance. They do have the other mentioned items though (narrowband O2, ECU).