New Member

[NHcamper]

Just purchased 1981 RQB 3352 from a gentleman in Las Vegas.

2016 AOAI lists previous owner as William J Mims Las Vegas NV.

The original build sheet indicates it was silver with burgundy interior. Highly optioned car. It is now midnight blue with red and white interior.

The original 305 has been replaced with a GM 350 Goodwrench. Not sure what trans but feels like turbo 350.

It is a respectable 10 footer with good frame and hog troughs. I plan on doing body and paint sometime in the future. Has a few mechanical issues that need addressing but hopefully not anything to extreme,non operational sky top but does not leak. 

I am looking forward to many years of enjoyment driving this car.

[Gunslinger]

Welcome to the world of the Avanti!  I hope you have a great time with your new purchase.  Visit often and tell everyone of your progress and adventures.  Many here have had to take care of issues and not always by the factory methods.

Again...welcome.

 

[NHcamper]

Thanks, Gunslinger. I drove this car RQB-3352 from LasVegas to NH 2763 miles. It has a replacement goodwrench 350.

The biggest issue I have is the brakes. I broke a fan belt and the tech that worked on the car said there is a vacuum problem. He said a manifold leak or carb leak was the most obvious culprit. No vacuum going to brake booster. I haven’t driven the car since I got home but plan to tackle it soon. I’m hoping that solving this problem will stop the miss at idle and fix the brake problem. I owned a 1981 30 years ago so I’m aware of the issues that arise, but I am excited to be back in the seat of an Avanti and looking forward to bringing this car back to a dependable daily driver.

[Gunslinger]

While not as likely as what the tech told you, don't overlook the brake booster as the source of the vacuum leak.  It's not unknown for a booster to fail internally and cause the problem.  Pull the large vacuum hose off the booster and plug it and see whether the vacuum reading stays the same or improves...if it stays the same you've eliminated the booster as a source of the problem.  Also...don't overlook the vacuum hose from the intake manifold to the vacuum gauge...it could be cracked from age and leaking.  

Hope you fix it easily and you have years of enjoyment with the car.  

[Paul K.]

Not sure if you got the problem, solved but NO vacuum at the booster sounds odd. Little vacuum at the booster is more likely from a leaking vacuum hose or manifold leak and  Could cause the rough/miss at idle and weaker brakes. :Like GS said above do that, however I would be listening carefully to what your "tech" says and future diagnosis. A vacuum leak on an old Chevy V8 can be found and diagnosed in a few minutes by an experienced mechanic THAT IS FAMILIAR WITH WORKING ON OLDER CARBURETTED  ENGINES. On another note, I'm curious if the previous owner deleted the GM computer controls and feedback carburetor when the engine was swapped? This would be a good thing IMO for future and maintenance but may cause problems if your state of residence requires emissions testing for 81 model year vehicles. 

Welcome to the board and keep us updated on progress. 

Edited October 21, 2018 by Paul K.

[NHcamper]

Not sure if I updated this post somewhere else or not, but I did solve the problem.

The booster was connected to a port on the carb spacer. The problem was there was no vacuum coming from that port? I used the port off the manifold that supplied vacuum to the dash gauge and something else, the threaded port on the top of this vacuum port had been blocked off? I used a standard NPT barb fitting and ran it to the booster and the brakes worked fine. The miss at idle was fouled plugs, P/O mixed platinum and ac Delco? Has been running fine. Don’t think computer is controlling anything?, has Edelbrock carb. Still has all the pollution stuff on it and smog pump is hooked up, has CAT, not sure if it is working or not? There are several things that need attention I will work on over the long winter and hopefully will be squared away by spring.