Engine dies at stop light. Need advice on adjustments

[Robert]

1963 88 NADA with Solex carburetter. Idle, acceleration and running are fine. When pulling up to stoplight and clutch in, engine wants to die. Foot or hand throttle increase keeps it running. Really would prefer not to increase the idle. Suggestions and advice? Thanks

[jimrr]

vacuum leak !! .......... check that spring on the flapper valve atop the carb intake too.

[roverp480]

Check the idle mixture strength is correct, may be slightly weak. If you snap the throttle open from idle then back to idle does it stall then? WS manual suggests if it does when the mixture is set correctly , the idle speed may be too low

[Robert]

Thanks, I'll check it out.

[Robert]

How do I check for a vacuum leak? Thanks

[jimrr]

unless you have a manifold to head leak which would be harder to find just look at the hoses coming off the intake manifold and carb. removing the hoses one at a time and capping the connection at the manifold would result in a slight increase in rpm. you can also hear a leak sometimes, for the hard to find ones spray some either or something around the suspect leaking spot and you'll definitely hear the rpm jump.
i assume you have a regular 2.25 litre so there are not many places for it to leak, brake booster, vacuum advance, there just are not many places to lose vacuum. more often it's carb adj.

[Robert]

Thanks again.

[Robert]

Hello. I adjusted the mixture screw and the idle. Not much apparent change using the mixture screw, but seems to idle better at a stop after driving, so I guess it did something to cure the problem. Workshop manual says 500 rpm idle, but I can't get under 900.
I would also like to check the timing. Timing cover is on the flywheel and looks like I need to remove it from underneath as my arms just aren't that long to reach it from the top. Any suggestions how to use a timing light as the workshop manual uses a 12v bulb. Thanks again for advice and suggestions

[jimrr]

timing light goes to first plug closest to radiator, hook to battery as normal. timing pointer is on crank end by radiator and close to block, invisible as covered in oil and road dust? if you don't have the pointer you'll have to pull the plug above the starter as I recall though i think i've only done that once. if you can't get to 600 rpm or less something is wrong, i'd suspect the stops for that adj. on the carb itself., ( the stop isn't the adj. screw but what it screws against or something near there.

[biffidum]

In all carbs not able to achieve low idle often means your smallest jet is plugged or restricted. You are likely running (barely) on a secondary (main) at 900rpm with your idle screw balancing act. Disassemble and clean your carb.

[Robert]

Will check the carb. Thanks. I think the timing pointer is on the flywheel, not the crank pulley. Would I put the timing light on the front plug in any case?

[roverp480]

Will check the carb. Thanks. I think the timing pointer is on the flywheel, not the crank pulley. Would I put the timing light on the front plug in any case?
Yes, timing based on Number One Cylinder

[jimrr]

yes

[Robert]

Thanks. Will do that.
Is the "economy" jet listed in the workshop manual the same as the idle jet?
I can't remove the economy jet as someone has ruined the slot. I can cut a new slot on the mill and hopefully remove the jet.
According to the parts book the only jet with the correct number is the main: 120.
Accelerator pump is 65, should be 50
Starter jet is 145, should be 130
Pilot jet is 65, should be 55
Economy jet should be 100 or 150. I don't know which is correct and don't know what I've got as I can't get it out

Thanks for the help, I really appreciate it.

[biffidum]

The pilot jet would be the one likely plugged. If you have a wire set you could simple "poke" it clean. I wouldn't mess with the economy jet at this point. Swap out your fuel filter while you are at it.

[Robert]

Thanks. All the jets are clean, but with the exception of the main, are the wrong number. Would this affect the idle?

[biffidum]

Certainly possible. If the pilot was wrong then for sure. Float level can affect everything too.

If this problem happened after it was working fine for a while, you may need to think along a different line. Unless upon reassembly it works well again. Be sure to follow the tuning sequence with the correct RPM (this affects which jet is feeding fuel) before setting an idle.