Dies when put into gear

[78c]

My two cents; 1. Choke pull off is not operating and opening up the choke. Choke pull off is not opening the choke plate far enough. 2. Intake manifold gasket. Had this issue many years ago. When cold the gasket is "shrunk" and leaks causing a vacuum leak. As the engine warms up the gasket swells and fills the leak and the engine operates properly until it cools again. Get a spray can of oil, start it cold and use the oil around the intake gasket area an see if the engine smooths out.

Where is the choke pull off at

 

[78c]

Yes it is

auto trans?

 

[78c]

Having experienced this behavior myself with my 67 Camaro, it sure sounds like a substantial vacuum leak. Especially since you mention removing the emissions equipment. On mine, it was a leak in part of the AIR system. Would idle fine but the moment it got put it in gear, died. I had a vacuum gauge that read a bit on the low side, but I couldn't isolate the problem. Didn't matter how much I increased the idle speed or messed with the air mixture. For the life of me, could not find the issue. I tried spraying carb cleaner around the carb and intake to see if the RPM changed, checked my hoses, PCV valve, fuel delivery, plugs... Turned out I had a leak in the diverter valve, which of course you don't have, but same behavior. As an aside, I had another non-Chevy with similar behavior where it would stall because the valves were too tight, but it tended to stall more when coming to a stop. Since you didn't mess with the heads, I can't see them being part of the problem anyway. With the behavior on your car as consistent as it sounds, I'm thinking vacuum leak like many others here...

So check all the vaccum lines from the carb and trans?

 

[78c]

Just back it in the garage from now on and the problem is solved.

? What does it do when I back it into the garage?

 

[mallard]

? What does it do when I back it into the garage?

He's being a smart a$$ (better than a dumb a$$). You described the problem as occurring after you've backed up and then put it in drive. So presumably if you're not starting out in reverse, you're starting in out in drive so no stalling problem because you're driving frontwards out of the garage.

 

[cadillac_al]

What is the part number for those spark plugs for a 1978 350?

Bosch 6712

 

[Mike Sinkoski]

Since we don’t know your whole set up, and you said you were low on power, Are you checking the timing with vac adv plugged? 8 is a little low especially on a modified engine( intake,headers & carb). I recommend running full manifold vac adv if your emissions exempt. I’m @20* idle on my Camaro with advance hooked up and mechanical adv limited for vortec heads, to give you an idea. A vac gauge is very useful tool and tell a lot on engine state of tune, you should be pulling around 17-19” (stockish cam) steady at idle, if not it could point to potential vac leaks, does all of your heating/cooling controls work?how about your evap canister valve? Even the vac advance can or vac modulator can leak. To eliminate the choke from troubleshooting, cold start the car on flat ground and let it run until the choke is visibly fully opened without throttle input and then see if it dies, if so your not dealing with a choke issue.

 

[78c]

Since we don’t know your whole set up, and you said you were low on power, Are you checking the timing with vac adv plugged? 8 is a little low especially on a modified engine( intake,headers & carb). I recommend running full manifold vac adv if your emissions exempt. I’m @20* idle on my Camaro with advance hooked up and mechanical adv limited for vortec heads, to give you an idea. A vac gauge is very useful tool and tell a lot on engine state of tune, you should be pulling around 17-19” (stockish cam) steady at idle, if not it could point to potential vac leaks, does all of your heating/cooling controls work?how about your evap canister valve? Even the vac advance can or vac modulator can leak. To eliminate the choke from troubleshooting, cold start the car on flat ground and let it run until the choke is visibly fully opened without throttle input and then see if it dies, if so your not dealing with a choke issue.

No on flat ground and in park reverse and neutral it wont die only when put into gear the first time it's a stock 350 with a edelbrock performer intake and the avs2 carb no emissions stuff at all just the pcv valve and vaccum line for the distributor my ac box hasn't worked since I owned it but the heater core works I dont have anything else that I know of.

 

[78c]

Bosch 6712

Awesome thankyou!

 

[Mike Sinkoski]

No on flat ground and in park reverse and neutral it wont die only when put into gear the first time it's a stock 350 with a edelbrock performer intake and the avs2 carb no emissions stuff at all just the pcv valve and vaccum line for the distributor my ac box hasn't worked since I owned it but the heater core works I dont have anything else that I know of.