289 dies if I give it gas

Thanks for the reply. I will use that chart and do a vacuum test next time it’s running
It has dual exhaust. 2” stainless no crossover

 

did you check the fuel pressure from the pumps or electric pump vs what is needed for the carb? that might help.
some carbs need lower or higher pressure.

 

Crazy idea, vacuum modulator is leaking .

 

Thanks for the reply
I have all the vacuum lines removed and capped/plugged all the ports

 

No I have not got a fuel pressure reading. I might set up an electric pump to test it out.

 

You can remove the fuel outlet hose on the pump, place it in a container and crank the engine over. There should be a good shot of gas coming out of it. Also those Autolites can be run with the top off. It’s likely not the problem as even a 2-bbl can idle for a couple minutes with just the fuel in the bowl and the fuel supply disconnected. It sounds like a massive vacuum leak when the butterfly’s crack open?

 

This weekend I will hook up the vacuum gauge and get some readings. I have been reading about smoking the engine as in blowing smoke into the manifold and see where it comes out. I don’t know if that is going to be useful. I would have to buy the smoke machine but do I need it?

 

Blowing smoke into an engine? that's a new one. Maybe blow some weed smoke in to "mellow" the idle.
What you might try is a propane hand torch, turned on low ,but not lit. Hold the torch to allow the gas to get near intake to head surfaces or anywhere it might be leaking vacuum. If your engine speeds up or changes , you've found the leak.

 

Buy some cheap seegars and be the smoke machine. It works, but don't inhale or you may end up doing the technicolor yawn!

 

Been following this thread, hope you don't give up and crush the old girl! That thing is a rare beast these days, and it looks to be in nice shape. Lots of stuff for you to mess with on this problem, but I'm leaning toward an electrical wire moving under load causing a short or open. Now, where is it?

 

Had the same problem with a 327 chevy, dist was 1 tooth off.

 

how do you get it under the inlet manifold to check for a valley leak? Smoke would come out the valve cover breather/pcv holes if there was a valley leak

 

Or go to your local bee keeper and ask them if you could borrow a hive smoker, used to keep bees docile when handling the hives

 

Did the vacuum test and got this result (see pic) this was a new rebuild when I got it and it looks fresh and clean inside. I will do a compression test next. I am guessing that they might have lined up the ring gaps. The oil looks and feels ok but I have never changed the oil so I might put some good oil in it and see if that makes a difference but doubt it will

 

Found a photo of my comet taken in 2008 when it was owned by somebody in CA. So 8 years and an engine bay fire and another owner before I got it

 

edit to add: so I was at the parts store to get manifold gasket kit and was lamenting to the counter guy about these problems and another customer says it could be a bad torque converter causing it to stall. I have been focus on ignition voltage and vacuum leaks and have not even checked the fluid level in the trans. Could a bad converter in a C4 be causing this? I don't think so but the aods have a mechanical lock up converter that can get stuck that causes an issue like trying to stop with a clutch out in gear

 

Finally got to do a compression test. Did the test cold and got 146 to 152 on all cylinders.

 

DO NOT LEAVE US HANGING on this one..please!
6sally6

 

He quit giving it gas!

 

Are we just going to ignore this???

 

Why not?

 

Worth him checking............. if and when the OP comes back.

 

Strange thing to look for , be sure vacuum advance arm is solidly connected to the breaker plate . Breaker plate floating will cause one to discover new potty words trying to locate the issue

 

Ya reckon the OP figured it out....yet ?!
Might be a loose timing chain.....junk in the fuel tank....Which ever.... gets him a bump-to-the-top....
6sally6

 

90% of fuel problems are electrical. Just sayin. What changed and when?

 

And it looks like he was on the H.A.M.B. this morning and not bothered to update his thread?

 

Does the carb have an anti-stall dash pot on it? I had one go bad on me, did exactly what you have described.

 

Check the firing order. 289 and 302 will run with the 351 firing order. A 5.0 cam swap changes the firing order. It will present exactly as the OP said. Will idle fine and rev up, but part throttle load kills it instantly