Idles smooth, stalls in gear

[Mi68Stang]

Hi, new to the board. I just bought a 68 coupe. It was a smoker when I bought it. We replaced the rings and cleaned everything. Had to replace the head due to the lovely broken vacuum port in the intake manifold. The head cracked while trying to remove the brass end. Got everything back together and cleaned the engine up a bit. Started right up after the juices started flowing. Adjusted the fuel mixture and idle, ran so smooth you could barely tell it was running. Put it in drive to take it out of the garage and it stalled. We've been meticulously going down the list of possibilities of the cause of the stalling and hesitation. We've checked all the vacuum lines, replaced the PCV valve on the breather, rebuilt the carb, timimg is dead on. Now we've replaced the carb. It's still hesitating and stalling when you give it the gas. What else can we do??? What does it sound like to any of you?

 

[slepe67]

If it has a mechanical fuel pump, try to replace it. I had a 351C that did the same exact thing, and the fuel pump was brand new. I replaced it and it ran like a champ. Just a suggestion....

 

[Platonic Solid]

I have to say it just to cover the base - old/bad gas can cause similar results.

Welcome,
not many from CT here

 

[Clark]

I agree with the earlier posts and I would like more information about the carb. On my setup with everything rebuilt nice and tight, I had to crack open the secondary's because it was not getting enough air. Is your choke wide open as well?

 

[jbuening]

Is it an automatic transmission? Try replacing the vacuum modulator on the trans. Mine was bad and it would jump forward and die when i put it in gear. Make sure the vacuum line is attached also.

 

[302 coupe]

what engine and carb are we talking about here?

 

[hungrymonkey]

vacuum leak?

I would spray some startig fluid around the intake and see if It revs up.

 

[latamud]

sounds like your float might be adjusted too low. Check your sight plugs while it idles. Get it to where fuel drizzles out a little and then back it down a bit until it stops. Put the plug back in and try that.
Can you rev the engine from idle in neutral/park?

 

[302 coupe]

if its a holley 4 barrel, check to make sure the secondary throttle blades are cracked open the right amount, I want to say that .030 of the the transition slot needs to be exposed.

I've had 3 vehicles that ran fine, but would always want to stall when put it in gear. I stumbed across the throttle blade adjustment idea somewhere, gave it a shot, and it worked on all three cars.

 

[Mi68Stang]

I want to thank everyone for the advise. Unfortunately we had to tear the engine down again to find out why it was smoking again. Two of the rings were in wrong, oops, live and learn. We did get the fuel pump on and checked that before we tore it down. That didn't seem to change anything. The motor is the original straight 6, 200 with the 1 bbl carb. The new carb is a Holley replacement for the Ford 1100. For some reason unless we held the butterfly open with a screwdriver it wouldn't start. Seems to like to be on the real lean side when running it on the road too. It is an automatic transmission. Once we get it all back together we'll see if it's better or the same. If not we'll take a look at the things you all suggested. It's much appreciated. He was ready for me to take it to a mechanic! I'll keep you informed or yell for help if we run into more trouble.

Michele