it turns out that someone pulled a shade tree and disconnected the vacuum advance on the distributor. I assume that they twisted the dist cap all the way around for more go power. I reconnected it and now it's obviously messed up. The only problem is that I have never messed with the timing on a vehicle before. Where do I start? If there is a great thread here that would give me good advice, feel free to direct me there. Otherwise, any help would be greatly appreciated.

I reconnected it and now it's obviously messed up.

Details! We need details! ...and don't panic!

What is it doing (or not doing) that makes you say it's messed up? Start at the beginning and give us the facts and symptoms...

The main symptom is the fact that it is missing. I'm no expert, bit it has a bad stumble when you first press the accelerator. And there is no happy medium as far as idle adjustment goes. It's either too low, or too high. I made all of the choke adjustments correctly, I'm sure of it, but it still smells like it's running rich. I turned the mix screws out 2 turns from seated, but I am going to try turning them in a half turn at first and work my way from there. I feel like I'm in over my head a bit, but I'm willing to keep at it until it's right. I just need some guidance.

I also found a leak in the exhaust manifold gasket where it bolts onto the block. How bad is that? Are exhaust mani's cleanable, or will I need to buy new ones? I would like to get this baby looking clean under the hood so that it is easier to diagnose and work on.

It sounds like you may have a vacuum leak somewhere in the intake stream. Since the exhaust gaskets between the manifold and head are leaking it will need corrected to be able to tune the engine. It would be best to replace the intake gasket as well.
Since the manifolds are seperate from each other it is sometimes difficult to get all the gaskets to seal. I have had the best results by cleaning all the surfaces down to shiny metal. Then leaving the bolts that connect the two pieces under the carb area loose until the manifolds are tightened to the head. Torquing the bolts is important and retorquing after a heat/cool cycle will be needed.

It sounds lean to me also. you can test this buy starting your eng. and cuping your hand over the the top of the carb. to slow air flow. don't try to seal it off or it will suck your hand in and stall. If idle comes up and missing goes away then you have a vacume leak. you also have to set your timing properly. If you do have a vacume leak you need to find out where it is. I have a way to do that but i don't want to tell someone that is not experienced because i don't want you to set your car on fire! mabye someone on this site could tell you a safe way of finding your leak if you have one. I hope this helps good luck.

A safe way is to spray carb cleaner or WD 40 around the intake gaskets at the head and under the carb. If the idle speed changes you found a leak. The "do not try this at home" method is to use starting fluid. It is extremely unsafe so DO NOT try it.

I didn't want to tell him about carb cleaner. I saw some people spray the distrbutor and bad things happened. plus you have to spray close in short bursts to find the leak. I don't want a beginner out there with something so valetol. WD-40 sounds safe i never tryed that. does it work?

I actually already knew about the carb cleaner-vac leak trick, but hadn't tried it yet. I had planned on replacing ALL vac lines anyway, so I haven't bothered to see if I had a leak yet. If the exhaust is leaking from the manifold, will that actually effect the way the motor runs? Lack of compression or whatnot?

I haven't been able to replace the vac lines yet because I do not have a diagram for them available. I can't find a Haynes or Chilton book anywhere locally, but they can order one. Can't find one on jollyrodder.com, nor anywhere else online. If anyone had one they could post here, that would be great.

I am also in the market for a fan shroud, as mine is missing, hence the lack of a diagram for vac lines. Is there a good aftermarket one avalible, or will I have to make one?

The canister that the vac lines run to just to the right of the radiator, is that a vac pump or just a charcoal canister for smog control? Could it be a culprit? There is a vac line on the front of the throttle body at the base of the carb that is just capped off, and I was wondering what that particular line ran to?


I'm going to try to stifle the airflow to the carb in the morning and let you know what that does for me. Might have some carb cleaner handy too, so might try that.

Thanks again for all the advice. Tryin' to keep the Nova legacy around, and I don't want to do things wrong and make people think "Geez, what a pile!"

one of the first things i'd recommend is to buy a repair manual for your specific car... even if some are better than others... even the worst has info that's needed to do work on the car.

sorry i have no vacuum diagrams, to be honest you're the first person to ever bring it to my attention... maybe i'll have to start a new quest.

i'd still recommend a Chilton, Clymer or a Haynes manual to start with, maybe even one of those would have a diagram for ya ;)

I use a propane torch (unlit) to provide the fuel for the air leak. It will improve the engine RPM when the head of the torch is pointed at the leak. Off course if your plug wires are arcing or you get around the distributor you could find yourself in the middle of a big fire ball.

When you are talk about an exhaust leak; are we talking about the exhaust manifolds or on from the top of the intake manifold in the center? Cast iron log exhaust manifolds can be wire brushed or sand blasted down to shiny metal and then painted with high temp spray paint. I recommend new bolts as they will be highly corroded.

Big Dave

When you are talk about an exhaust leak; are we talking about the exhaust manifolds or on from the top of the intake manifold in the center?

Big Dave

It's leaking where the exhaust manifold bolts onto the block, next to the spark plugs. There's a small puff of vapor that escapes every time that cylinder hits.

Does this effect compression?

No it is just annoying, hurts nothing. I use Percy's "Sealed For Good" dead soft aluminum metal exhaust gaskets as they are warranted for life. The stock cast iron is machined to be perfectly flat and has only a thin asbestos fiber gasket to seal it up. Headers are even more prone to warpage because the metal is lighter (heat concentrates around the ports and other parts of the tube header are cool so it twists the metal, warping everything).

Big Dave

Thanks for taking that load off my back. Now I can concentrate on tthe other stuff. Going to get a haynes book tomorrow. If there is a diagram in there, I'll scan it and post here for all.

It will affect the tune of the engine and will only get worse as the hot gases keep buring off more and more of the gasket. Left long enough the metal will also start to burn away.