I've got a 1984 Berlinetta with the 2.8L V6, 2bbl Varajet carburetor.

I've been shooting a trouble code 54 for the Mixture Control Solenoid. I rebuilt the carburetor and installed a new MCS and am still getting the trouble code after resetting the computer! My mileage is still horrendous as well.

I do NOT hear any clicking/cycling from the MCS, both the old and new ones, when the ignition is in the on position.

Is there any way to test the wiring or circuit to ensure that there isn't a short/cut wire/ground problem any other issues in the wiring?

 

Have no specific info, but I believe you'd start with a dwell meter to check for the pulses to the solenoid. Start your research with that.

 

+1

Rebuilding feedback carbs entails a lot more than just buying a kit and replacing the solenoid. Did you adjust the solenoid travel end points?

 

No I didn't, there weren't any instructions for that adjustment included in the rebuild kit.

 

My apologies. I'm getting the Varajet mixed up with the Dualjet (looks like the front half of a Quadrajet).

I've been looking online and some articles seem to suggest that the Varajet requires some kind of mixture control adjustment, but I haven't been able to find any specific how-tos.

 

Get a service manual and follow the diagnostic trees. Not all cars/engines/models made the MC solenoid click when turned to the run position. Oldsmobiles used basically the same carbs as Chevys but the programming was different and would NEVER click the solenoid when turned to the key-on position. Little old blue-haired ladies get all freaked out when they turn the key and hear something clicking under the hood, I guess!

Gotta see it like the ECM sees it or you'll chase your tail for weeks.

One thing I can tell you about ALL GM carb MC solenoids... you can test them yourself very easily. Unlike other various delicate engine sensors, they run on full battery voltage (12V). That means you can rig up some test wires straight from the battery to the 2 terminals on the solenoid connector. When you apply 12V across the terminals you should hear a click. When you break the circuit you should again hear a click. It's just an electromagnet working against the tension of a small spring. They're rugged as all get-out. You won't fry it and you won't break it testing in this way.

If she clicks, she's workin'. If she don't, she ain't.

 

For a few bucks, these might be worth downloading:

http://carburetor-manual.com/-c-5.html