Need Help Tonight Please!

[Frank D.]

[1965 327/300 automatic] I have a very hard-to-get a/c shop appointment early tomorrow morning and I have encountered a problem. I installed my rebuilt carburetor this morning (Dick Katter). The engine is running a little erratically and each time I put the car into 'drive' the car stalls. Checked all the vacuum lines, especially the one going to the automatic transmission. Any ideas what might be causing this? If I quickly shift the powerglide to "low" gear instead of "drive" it will run for a few seconds but then stalls also.

Been working since 7:30am and am out of answers. As usual, thanks in advance for your suggestions.

Frank O'Donnell
Charlottesville, VA

[Joe R.]

Re: Need Help Tonight Please!

Frank,

My suggestion would be to take a flat blade screwdriver and crank up the idle until it won't kill the engine when put in gear.

Keep the appointment in the morning and worry about this problem when you have time.

Usually you have to set the idle air screws on both sides of the primary block and then set the idle for the desired idle RPM.

JR

[Frank D.]

Re: Need Help Tonight Please!

Joe:
Thanks for the quick reply. The engine is idling at 1500 rpm when I start it, but I'll try your solution and see if it stays running.

Thank you.

[Bob R.]

Re: Need Help Tonight Please!

You may have the fast idle at 1500 but what does it idle at as the engine warms up? I think the manual states 450 or 500 for hot idle but with current fuels and the posibility your car emgine may not be stock it may need to be set close to 700 to idle smooth. I know my 63 with powerglide will not idle at 500 rpm.

[David P.]

Re: Need Help Tonight Please!

Sounds like idle mixture might need to be adjusted. Could be too lean. You could back the idle mistures screws out 1/8 turn or so at a time and check results.

DAP

[Timothy B.]

Re: Need Help Tonight Please!

I agree with all posters, one thing to keep in mind FWIW. If the carburetor is overhauled properly do all the adjustments with the engine at operating temperature fully warmed up. Does this 300hp engine have it's stock camshaft?

If you find the car needs to idle high (9-1000 rpm) just to drop in gear and hold idle without stalling then the motor is running to lean. If you can't enrich the mixture and make it happy take some timing out of the motor and then you will need to enrich the mixture by exposing more transfer slot (idle screw) or emulsion screws.

Too much timing will let the motor run with lean mixtures and at idle it may seem fine but under load it's needs more fuel. A indicator of this is when there is a great (300+) rpm difference between idle speed and idle speed in drive with automatic.

I think todays gasoline is a little different than tuning with older fuel so slight changes from the factory specs can help.

[Clem Z.]

Re: Need Help Tonight Please!

if the carb is a holley he may have installed the wrong power valve and when the engine is loaded down with the trans in gear the vacuum falls off and the power valve opens and over fuels the engine.

[Loren L.]

Re: Need Help Tonight Please!

Vacuum leak somewhere.

[Frank D.]

Re: Need Help Tonight Please!

Thanks for all the great posts last night. Back at it early this morning.

Bob: Drive "hot" idle is about 550rpm. I adjusted the idle up last night; it still stalls but not immediately as before.
David: been playing with the idle screws along the way to smooth out the idle.
Timothy: Original engine, but the stock camshaft was replaced with a slightly more aggressive one to even out the power band. I will take a little timing out as you suggested. What is an "emulsion" screw (new term to me.)?
Clem: The carb is a Carter AFB restored this month by expert Dick Katter of Manassas, VA.
Loren: will recheck all hoses for vacuum leak. Have the carb tightened down to the four anchoring posts, but not too tight.

Thanks again guys, I'll try everything you suggested. Still trying to get to my appointment this morning.
Frank

[Clem Z.]

Re: Need Help Tonight Please!

if the cam produces lower vacuum at idle you may need to change the power piston springs to lower tension ones so the metering rods do not go on to rich when the engine vacuum drops when you put it in gear. you can test this by removing the power piston springs and reinstalling the metering rods as this will prevent the metering rods from going to rich and try the engine and if the problem goes away you need lighter power piston springs

[Timothy B.]

Re: Need Help Tonight Please!

Frank,

My suggestion FOR A TEST is to block the vacuum advance with a golf tee and time the engine at 12-14*BTDC. After that set the idle and readjust the emulsion screws (they are the front air/fuel screws in the AFB). See if that helps the rpm drop when going from neutral to drive.

I don't as much as others here but IMO there is not enough slippage in the torque converter with your hot rod cam and the overlap is causing a soft lower rpm range. If you reduce the engine efficency at idle by taking some timing out, you can richen it some by exposing a little more transfer slot (idle screw) and it may have better manors when you put the car in gear.

[Domenic T.]

Re: Need Help Tonight Please!

Vacuum leak somewhere.

I agree, along with a few adjustments.

DOM

[Frank D.]

Re: Need Help Tonight Please!

Engine stall. Here's the answer to all the posts!
I followed all of your excellent suggestions. I advanced the timing, reset the drive idle to 700-800 rpm and reset the mixtures screws to smooth out the engine. Used the smoke machine to check all vacuum lines for a leak, with no problems found. With this completed, the engine will shift into gear. and the car will run.

However, (nothing is simple with a 45 year old car as we all know) with the car running properly there was a strange 'clanking' noise coming from under the car from time to time, but not consistently. We put the car on the lift while it was running and discovered my torque converter is defective. Timothy B was right on the money when he mentioned slippage in his post.

Thanks to all who posted. The Tech discussion board is the best source for real information when you need it.