Hi guys!

I'm glad to find this forum. I'm 29 years old, and live in Charlotte, NC. I have an old 66 Valiant that I bought years ago in high school... Sadly she's been sitting for a few years, and I'm trying to get her up and running again. The reason I parked the car years ago was because I had other cars, and the brakes were god awful on the Valiant.

Anyways, I've been working on the brakes lately, but I've ran into some engine problems. I believe the problems are air/vacuum related, but I'm no expert so I thought I'd ask the fine experts here!

The car has been running with a rough idle for the past few months, I just start it from time to time to keep the battery charged and turn the engine over a bit. When you get in the gas pedal, the car smokes a bit, so I think I've got too much fuel pumping through the carb... it's been 'upgraded' to the super six setup with a 2bbl carter carb on it. The carb was rebuilt (as was the engine!) 7 or 8 years ago, and it hasn't been driven much at all since then.

So I recently added a brake booster to the car, to give it power brakes. I hooked a vacuum line from the brake booster to the intake port on the back of the intake, to power the brake booster. I'm not 100% that this is the source of my problems, but maybe you can tell me better than I.

When I started the car earlier today, the engine would die almost immediately. It was acting like I was flooding the carb out, so I usually could only get it to start if I held the pedal to the floor, cranked it for a few seconds, and it'd spit and sputter and fire off.

So I first checked to make sure it was getting good fuel, I could see the jets spraying inside the carb when I advanced the throttle, and I checked the fuel filter which seemed to be nice and clean. I've got plenty of gas in the tank, as well.

So then I checked the spark plugs, and they were horribly fouled out, really black I assume from too much gas, again. I don't know if that's just from me pumping the pedal too much when I'm starting it, or if it's because the carb is misadjusted.

So I bought new plugs, went back home, replaced them, checked the distributor cap and the rotor (it's had an electronic ignition installed, so no points), and the cap and button looked fine.

So, finally, I discovered that if I don't touch the throttle, and finagle the choke enough so that the butterfly on the 2bbl stays open, the car will start and idle for several minutes, although it's at a low idle since I've got the choke effectively 'disabled' by rigging the butterfly open like that.

If you press the gas, the choke pulls the butterfly back closed, and the car almost immediately dies.

So, can anybody help me understand how the air flow and vaccuum system is working on this thing? I've apparently messed something up, but I honestly don't even understand the air/fuel mixture thing that goes on in the intake/head/carbureator. Any advice would be appreciated! Should I turn the carb jets down? Remove the brake booster? (I'd hate to do that, I really like the idea of power brakes!)? Any help is appreciated.

Welcome to the board.

First thing I would do is unhook the booster and plug the manifold port, if that changes how it runs, you have a bad booster.

What kind of carb? holley or carter?

It does sound like you are dumping to much gas, could be just a stuck float. Have you rebuilt the carb yet?

I am fairly local to you, pm me and maybe I can help.

good luck
TopHat

It is very interesting to hear your Valiant story. It is almost identical to mine. I have a 64 Valiant w/225 that I overhauled and then I installed the 2 barrel intake and Carter carb. Then because of a divorce and other issues I quit working on the car, that was about 6-7 years ago. Over the years I drove it occasionally or cranked it and let it run. As things went wrong with it I didn't fix them, so it got to where it was only cranked once and awhile. Earlier this year I finally got the bug back and have gone back to work on the car. I had almost the exact same problems that you are describing. If you haven' already done so, you need to get rid of the old gas in the tank or dilute and run the car until the old gas is gone. My problem was mainly with the carb. I adjusted the idle mixture and got it to run and crank reliably. The more I have driven the car the better it runs. However, I am about convinced that I will have to rebuild the carb. I have a slight miss at idle that I can't get rid of any other way. By the way I live just 30 mi. from Charlotte down in Lincolnton. Good luck.

Thanks for the replies, guys. As I thought about it more today, I'm not so positive that the carb was ever rebuilt in the first place. I remember rebuilding a carb, but I'm pretty sure it was the 1bbl holly that was on it in the first place! I got the super six setup off a dart I got and parted out, and looking back I don't think I ever even rebuilt the carb... so I'm going to try that first. I'm also going to check to see if the brake booster is bad, but it's a new booster I just installed about 3 months ago... and with the dark smoke out the tailpipe and the fouled plugs, I've got to have some sort of carbueuration issue going on... I'll update and let everybody know what happens in the next few days.

Well, I rebuilt the carb, and the car is up and running again! My only issue with the carb now is that there's a hesitation when you step on it, which I imagine has something to do with the idle mixture. Does anybody have any tips on exactly the best way to adjust the idle mixture on the car? Basically, I turned the needles all in, then backed them out two turns, the car starts and drives but hesitates under acceleration.

It's a Carter 2bbl, 82 slant six in a '66 Valiant with a 904 Automatic transmission.

Check the distributor, a blown vacuum advance pod or stuck mechanical advance weights would cause the off-idle hesatation.
DD