74 brook it runs but in gear it stalls or idles poorly

[74bronk]

i have a holley truck avenger carb had it rebuilt. Motor is a 302 by the way. replaced basically all ignition system except the coil. (truck had been sitting a couple of years) it starts up good cold. then after it warms up when you put it in gear the idle drops real low then if you don't put your foot in it it will stall.....i adjusted the idle control yeah i can turn the idle up but in park it idles really high and when you put it in gear it lunges. also in gear while idling the motor vibrates and shakes....not sure what that is about. so i believe there is something im missing on the carb setting any help would be appreciated! if something else please let me know

 

[Skiddy]

is the choke opening up after it warms up?

 

[blubuckaroo]

A couple of things to check...
Since it's been sitting, there could be dried fuel deposits in the idle air bleed ports. When they get plugged up, it makes idle mixture adjustment impossible. A little spray carb cleaner on the bleed ports while it's running will usually clear it up.

The other thing is Holley's power valve. If it gets a crack in the diaphragm, it the high vacuum of idle won't hold it closed.

 

[74bronk]

Yes forgot to mention choke is wide open

 

[bronkenn]

Choke shouldn't be wide open until it's fully warmed up. Sounds like you need to get the choke operating properly. Ken

 

[Rustytruck]

Check everywhere for vacuum leaks. I find this is common with low speed drivability problems.

 

[DirtDonk]

You said you replaced all the ignition components other than the coil. Was this related to the issue you're describing, or were you replacing them for other reasons?
Why did you not replace the coil? Can you check it with an ohm-meter to make sure it's still within spec? Maybe it's getting old and does not like life when it's warmed up.
Generally, when they go bad and heat up, you don't get any spark at all. But I would imagine it's not impossible for one to simply produce a much weaker spark that won't keep the engine running.

Back to the carb though, did it do this only after the rebuild? Or was that the reason you had it rebuilt in the first place?

Paul

 

[74bronk]

You said you replaced all the ignition components other than the coil. Was this related to the issue you're describing, or were you replacing them for other reasons?
Why did you not replace the coil? Can you check it with an ohm-meter to make sure it's still within spec? Maybe it's getting old and does not like life when it's warmed up.
Generally, when they go bad and heat up, you don't get any spark at all. But I would imagine it's not impossible for one to simply produce a much weaker spark that won't keep the engine running.

Back to the carb though, did it do this only after the rebuild? Or was that the reason you had it rebuilt in the first place?

Paul

Ok so vehicle had been sitting about 2-3 years ran tried starting it abou 8 months ago and wouldn’t start found bad gas in tank. Had carb rebuilt replaced spark plugs plug wires cap and rotor . Got it startered and now it idles up and down and in gear it stalls constantly even with the idle turned up high.

 

[74bronk]

Choke shouldn't be wide open until it's fully warmed up. Sounds like you need to get the choke operating properly. Ken

Choke should be good I’m in Nevada so it’s warm here as soon as vehicle starts the choke opens up

 

[Slowleak]

Got it startered and now it idles up and down and in gear it stalls constantly even with the idle turned up high.

Both of those are symptoms of a vacuum leak. It can also happen if your vacuum advance is connected to full manifold vacuum. When the vacuum drops, timing gets retarded, then the idle drops more, vacuum drops more, idle drops even more, and it stalls....

 

[Skiddy]

Ok so vehicle had been sitting about 2-3 years ran tried starting it abou 8 months ago and wouldn’t start found bad gas in tank. Had carb rebuilt replaced spark plugs plug wires cap and rotor . Got it startered and now it idles up and down and in gear it stalls constantly even with the idle turned up high.

ahh so a mouse chewed through a vacuum line, maybe

 

[pcf_mark]

Where is your vacuum advance connected to?