By Kevinpdx (Kevinpdx) (216.161.86.66) on Tuesday, July 24, 2001 - 11:17 pm:

My 1979 1500cvcc will not hold a steady idle. I bought a new carb, and have replaced both base gaskets and replaced all vaccuum hoses. She still fluxuates by about 300 rpms. It will also die if you come to a sudden stop or tight turn. This is an exasperating problem. Does anyone have any way to fix this?

By Anonymous (203.96.111.201) on Wednesday, July 25, 2001 - 05:05 am:

have u looked at the lobes on ya cam real close..i had the same problem in my 1200...and eventually it stopped all together and we discovered the lobes on the 3rd cylinder were worn so bad they no longer opened the valves

By Brian Wilborn (24.4.254.106) on Wednesday, July 25, 2001 - 09:43 pm:

Kevin, I have the exact same problems as you. I *also* own a '79 CVCC and my idle fluctuates about the same amount, and if if stop too fast (say at a red light coming off the freeway) it has a tendancy to drop the revs too fast and die. I have just rebuilt my motor (but not the carb) and all of the gaskets are new, all of the hoses are practically new and it otherwise runs fine. What I have done is increase the idle speed to about 1100-1200 RPMs and this helps with the rev dropoff problem, but it is definately a workaround. Is your carb new new or rebuilt new? I recently bought a "rebuilt" carb that wasn't worth a damn (except parts). I'm thinking that it may be one of the multitude of vacuum apparatuses for emissions. Is your car a California or 49 states model?

By Kevinpdx (Kevinpdx) (216.161.86.130) on Wednesday, July 25, 2001 - 11:15 pm:

The carb is a rebuild, and is a 49 states model. Could it be a warped base plate? Or a crack in the heat sheild gasket? My only plan right now is to agian replace the base gaskets, the base plate and heat shield. That is if I can find a new base plate. My reasoning for this is when I spray carb cleaner around the base the idle levels out and then goes back to its usual up and down.

By Farfignugen (12.110.136.90) on Thursday, July 26, 2001 - 09:29 am:

good eye kevin! I had similar problems with my carb, and thats almost the exact test that mechanics do for it. I sprayed some carb cleaner or some other flammable spray around the gaskets of the carb and intake. There's a completely different pressure inside there, and so if there is a small vacuum leak, the added fuel will affect the idle almost instantly. On occasion mechanics use a smoke test for this as well. I would definetly suggest replacing the seals around the carb. On the base of the carb, I decided to cut out my own gasket (the one between the hard plastic spacer and the intake) because I couldn't find one at the shops. Don't be afraid to apply gasket glue, it really helps.

By Brian Wilborn (24.4.254.106) on Thursday, July 26, 2001 - 05:21 pm:

You know, I've done all of the above Farf, even replaced the gasket *inside* that plastic base block (now that was a job and a half), guess what? Still does it. At this point I am ready to spring $50 or so for a new plastic block and if that doesn't work, I may even replace the intake manifold (who knows, maybe the machined surface isn't flat).

By Kevinpdx (Kevinpdx) (207.225.66.182) on Thursday, July 26, 2001 - 10:12 pm:

Brian I think that your idea of replacing the the platic block may be the ticket. that is what I will attempt this weekend, and we will see what happens.

By Brian Wilborn (24.4.254.106) on Friday, July 27, 2001 - 07:14 pm:

Cool, let me know. As I said, I just rebuilt my motor (got about 300 miles on it) and other than these little niggling problems it runs super. As a matter of fact, my car has always had this problem for the 5 years or so I've owned it. It'd be super-cool if this fixes the problem.

By Rick B (24.162.166.227) on Wednesday, August 08, 2001 - 12:44 pm:

One more thing to check out is the seal of the throttle shaft and the carb body/housing. These wear and will allow an air leak and are seldom fixed when overhauled. I seem to remember that there was a carb shop (for quadjets) which offered a kit to ream out the body and press in a bushing which was then machined to fit the throttle shaft or if you got a replacement shaft or whatever. You can check this by spraying carb cleaner in the area of the throttle shaft where it goes into the throttle body (usually the side where the return spring is located is the most worn) or by using a dab of grease (messy). Perhaps you can find a carb shop or machine shop to do the work for you locally if this is the problem. Good Luck