350 w/ A/C Idle Speed w/o Solenoid?

[RyanAK]

Hey gang. The ‘78 Suburban has a GM crate stock 350 with factory air. Quadrajet carb without the A/C idle compensation solenoid. Wondering what anyone else with this setup is setting the warm idle to. Right now I’m at 850rpm in Park. In drive with the air on I’m barely at 500 and it sounds like it’s struggling a little. I could bump the idle up a bit, but don’t want to get out of the idle circuit in Park with the air off. Thoughts? Bump it up or search out a solenoid?

R

[AussieinNC]

Here ya go...

https://www.summitracing.com/parts/s...iABEgKpuvD_BwE

You could also check out a second hand one from a wrecker....

[RyanAK]

I’ve looked at new and NOS and used ones... I can’t see how it would mount on the carb. Does the bracket attach to the carb body or part of the throttle linkage? My wiring harness has the connector that ties into the A/C compressor power... but I’m not seeing how to mount the solenoid...

[AcampoDave]

Coincidentally you posted this on the same day I was messing with mine. I don't have a compensator so i ended up driving around in a low traffic area and bumped up my idle a little at a time until I achieved a happy medium. I didn't take note of the specific RPM's but iI know I got it above 500 when all was said and done. It still slows down a bit more than I wished it did when the compressor kicks and conversely it idles a little higher than I wish it did when it clicks off. I only have a 283 so I dont have an abundance of off idle torque. Sometimes when it's really hot I use my right foot for a compensator

[geezer#99]

Originally Posted by RyanAK

I’ve looked at new and NOS and used ones... I can’t see how it would mount on the carb. Does the bracket attach to the carb body or part of the throttle linkage? My wiring harness has the connector that ties into the A/C compressor power... but I’m not seeing how to mount the solenoid...

Post a pic of the front and drivers side of your carb.
Some had a couple threaded holes that the bracket bolted to.

[RyanAK]

[geezer#99]

Only one useful threaded hole to use.
Likely won’t take much to make a custom bracket using that hole and an intake bolt.

Get creative!

[tdangle]

My 70 when with the original engine did not have the kick up solenoid and worked just fine with the A/C on. If I remember the idle with the A/C on was 550 in drive. Try it, no cost and you can always reset the idle speed it thing dont work for you.

[AussieinNC]

You need this style of bracket if there are no screw holes on the carb body...

[RyanAK]

Hey! There's a bracket! I've been looking and it looks like there's one that hooks to the cast-in T-post on the front and cast square bolster on the driverside corner. So that's two that would work. Great!

In the meantime, I bumped up the idle in drive with A/C on to about 550rpm. That keeps the engine sounding good at a stoplight and doesn't make me nervous it'll stall out. Idle in Park without A/C ended a little high... maybe 900-950. But I think I'm still in the carb's idle circuit and I haven't had any dieseling. So hopefully I'm good for the time being. It's getting hot here!

R