Stalls when coming to stop light

Sorry I have not been on in a couple of days... I got very ill with food poisoning. Rough stuff.

Anyway... teapot carbs are tricky ... I have stopped doing simple jiffy kits on them because there is so much that needs to be cleaned out from over the years, sitting, corrosion, etc. The idle circuits are obviously very small, like they are on many carbs, but if the rebuilder soaked the carb and then forgot to blow out just one idle circuit with compressed air, odds are that junk is clogging it up.

Scicala and Hoosier have way more experience than I do with teapots, and they could probably steer you in a much better direction, but I would suggest going to a website the Old Car Manual Project and printing off the Holley 4000 carburetor manual - it is FREE to do.

I really believe you may have to remove the carb and check it out. It will not need a complete rebuild of course, but you could partially disassemble, use good carb cleaner, compressed air, and make sure everything is clear.

One thing quickly comes to mind ... there is a check ball (yep there are a few in the old 4000's) that either needs to be removed/installed depending on what transmission you are running. The manual would show you that. I would check for that too....unfortunately I am at the office and don't have all my paperwork in front of me to tell you which it is.

maybe some of the other old-timers can chime in here....
 
I am still having the stalling problem. Since I set the timing to 12 BTDC the engine has stop stalling but the idle is very, very rough( like it's getting ready to stall). So much that the car shakes. Put it in N or P and its fine. Hoosier Hurricane responded in this thread that it could be that the timing chain could be off a notch. Has anyone had any experience with this kind of stalling cause by the timing being a notch off. If so, is there anyway to be sure that it is off a notch without pulling the entire front cover?
 
scicala said:
If you increased the timing from 6 to 14 degrees BTDC, then I assume you had to turn down the idles speed a little bit too. This puts the throttle plates in a different position in relation to the idle discharge holes, and probably needs the two mixture screws adjusted. Using a vacuum gage is best, but can do it by ear for best speed and smoothness too.
A sloppy throttle shaft vacuum leak can be an issue, but if you're car idled good earlier, then I doubt if the throttle shaft is a problem.
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Have you tried this (above) that I posted earlier ?
 
Could some say more about what Hoosier Hurricane suggested about this "stalling" could be a result of a cam being a tooth off. Has anyone had any experience with this problem and is there a way to tell for sure that this is the problem without tearing off the front of the engine.
 
Yes I adjusted the idle screws by the procedure in the carb 4000 shop manual. The engine seems to idle OK when in P or N, put it in gear and rpms drop from 7-800 to 4-300 then the engine stalls after running rough as the rpms decrease.
 
Have you checked the timing when in gear? I had an engine the idled perfectly at 800rpm but put it into gear the revs would drop to 300-400 then stall, it turned out the the springs for the mechanical advance were weak and a 700 the timing was advancing on the springs.... Set the timing at 13-14 degrees in drive and see if this could be your problem, or simply put the timing light on and see if timing retards when you put it in gear
 
cjc56:

Here's a quick and dirty way to check cam timing. Take off a valve cover, and turn the engine over by hand, watching the exhaust valve on either #1 or #6, depending on which cover you removed. As the exhaust valve is nearly closed, the intake valve will start to open. This is called the overlap position. When both valves are equally open, verified by placing a straightedge across the valve spring retainers, the timing pointer should be very close to the 0 mark on the pulley. If it is off by say, 3/4", the cam is out of time. Oh, do you have the genuine T-Bird front pulley? Passenger car pulleys have the marks on the damper ring, which are known to slip on the pulley and throw the timing marks off. Speaking of cams, do you have the stock cam in it or an aftermarket performance cam? Many performance cams do not idle well.

John
 
Good advice by Hoosier Hurricane. If the cam timing and front pulley both check out ok, you're symptoms sound a lot like a vacuum leak too. I know you have already checked for that, but maybe if you have power brakes, there could be a leak there. Maybe plug off any vacuum line from the intake and try the idle again.
 
Hoosier Hurricane said:
cjc56:

Oh, do you have the genuine T-Bird front pulley? Passenger car pulleys have the marks on the damper ring, which are known to slip on the pulley and throw the timing marks off.

John
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FYI. a T-Bird style pulley with an arrow pointing to the timing marks.
 

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Could be a tooth off, but should run really crappy all the time; especially at higher engine speeds.

Assuming the timing marks are correct as dmsfrr discusses, sounds a lot like a vacuum leak. They can be very hard to detect. While the engine is running, spray some starting fluid all around the carb, the vacuum lines, and the manifold to head split. Starting fluid is very explosive, so keep the spray away from any sparks or very high heat points. Keep a fire extinguisher handy and protect your eyes. Do the test out side away from buildings. An increase in idle speed at any point indicates a leak. The absence of an increase does not necessarily eliminate the possibility that you have a vacuum leak; it could be in the carb at a point where you cannot access with your spray.

Good Luck.
 
Thanks, I do have a tbird pulley/damper. I am currently having my carb checked out to be sure there is not a problem there. In the meantime I will check the timing as was previously suggested. Once the carb is returned I will block all vac and see whar happens. FYT no power brakes. I will repost next weekend on my finding. THANKS EVERYONE!!!!!!!!!!!
 
Vacuum Leak?? I discovered a hard-to-find place for one.
At the top rear of the intake manifold just above the passage to cyl #8, there are two cast bolt holes for holding the throttle bracket in place. If someone forces too long a bolt into the shorter hole closest to the carb it will break out the bottom of the hole and cause a vacuum leak.
 

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Motorhead6 said:
Could be a tooth off, but should run really crappy all the time; especially at higher engine speeds.

Assuming the timing marks are correct as dmsfrr discusses, sounds a lot like a vacuum leak. They can be very hard to detect. While the engine is running, spray some starting fluid all around the carb, the vacuum lines, and the manifold to head split. Starting fluid is very explosive, so keep the spray away from any sparks or very high heat points. Keep a fire extinguisher handy and protect your eyes. Do the test out side away from buildings. An increase in idle speed at any point indicates a leak. The absence of an increase does not necessarily eliminate the possibility that you have a vacuum leak; it could be in the carb at a point where you cannot access with your spray.

Good Luck.
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A propane bottle works well for this too... attach a hose to a common propane bottle from your hardware store that way you could get the tip of the hose to areas that are difficult to access. If the idle improves then you know where your vacuum leak is located.
 
If it runs smooth at idle but stalls with shudder under load then the engine is lean, lacking fuel. I would be looking into the idle cicuits, there are 2 idle circuits. One circuit may be working well enough that the engine will idle but when under load it cannot supply enough to compensate for the other circuit either partially functioning or failing altogether.
If the timing were off by a tooth the motor wouldn't run right at all.
Try messing with your idle richness screws - theres 2 of them, one for each circuit. Run one of them out by 1/2turn and allow time for the change to take effect, walk to the rear of the car and the exhaust should be rich; turn the screw back and check the richness at rear, it should be less; then turn the other idle screw the same amout as the previous screw and see if the engine reacts the sam as it did when you made the first richness adjustment.
The idle richness screws should be out the same amount on either side, I bench set them just under 1 full turn. Very few carbs want more than a full turn, especially with stock cam and strong vacuum.
Teapots are hateful carbs.
How hot to touch is your coil? Did you get the Pertronix coil to match the Pertronix module? 12v? Lots of carb problems are ignition, weak spark will symptomize like lack of fuel too.
 
The engine does run very well once you get it going on the road. I do have a Petronix coil to match the unit in the dist. The propane is a good idea. I have always used carb fluid. I have noticed a small vac leak (using carb fluid) around the throttle shaft but didn't think it was large enough to cause this kind of problem. Anyway I have sent the carb out for testing. I will let everyone know the out come.
 
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