Choke not closing on rebuilt quadrajet

[yellowdog5]

Our 79 Silverado 400 (it's our old firewood and livestock hauling truck, doesn't get a lot of use) recently quit on me and wouldn't start. Seemed electrical because it just shut off all at once. Gave it a tuneup and it still wasn't right, so I had a guy come figure it out, he fixed a vacuum leak and it was running quite well, but given the history of the truck and the fact that the carburetor was really dirty and the electric choke wasn't turning off, he suggested rebuilding the carburetor. I bought parts and had him rebuild it, he brought it out and got the truck running, but the next morning I had a really hard time starting it. The mechanic had told me that I should only have to pump the accelerator 3 times before starting. Had him come back out, he found a couple of small leaks, adjusted the idle and did something with the electric choke, it started a few hours later for me but then the next morning it wouldn't start at all when cold. I didn't have time last week to look at it, can't get ahold of the mechanic, (I won't recommend him). In looking through this forum I wondered if it might be choke adjustment. I went out just now and did the 3 pumps without trying to start it, got out and looked and the choke is wide open. Can anyone help? I'm not a mechanic but do most of my own work when I can figure out what to do, so I'm hoping to figure it out. Sorry this is long, I wanted to paint a good picture. Oh, also he didn't have me get a float, so it's not been replaced, I've only learned in the last couple of days that it doesn't come with the kit and I don't know much about carburetors, trying to learn.

 

[73c20jim]

Mine is one pump and it starts. Have electric choke, but live in warm climate.

 

[bucket]

I daily drive my '78, in the dead of winter, when it's down around 0°, three pumps usually does the job.

 

[bucket]

The choke linkage might just be getting hung up. Is it an electric choke or does it have a heat stove on the intake?

 

[73c20jim]

I daily drive my '78, in the dead of winter, when it's down around 0°, three pumps usually does the job.

Could the carburetor be draining back towards the fuel pump, so it has to be filled before it can start???

 

[yellowdog5]

The choke linkage might just be getting hung up. Is it an electric choke or does it have a heat stove on the intake?

Not sure what a heat stove is, it has the round thermostatic heater on the passenger side. I am really ignorant when it comes to carburetors, please bear with me, I don't know where else to turn. I did watch a video on adjusting the choke when it's cold, going to try that in the morning when it's pretty cool. Should I spray some lubricant on the linkage?

 

[yellowdog5]

Could the carburetor be draining back towards the fuel pump, so it has to be filled before it can start???

Yes I think it could be. How would I fix that? And how would I figure out if that's what it is? I did check the filter, and there was gas there.

 

[yellowdog5]

I daily drive my '78, in the dead of winter, when it's down around 0°, three pumps usually does the job.

Yes, that's what he told me it would take after the rebuild, I don't think he's going to help me figure it out.

 

[bucket]

Not sure what a heat stove is, it has the round thermostatic heater on the passenger side. I am really ignorant when it comes to carburetors, please bear with me, I don't know where else to turn. I did watch a video on adjusting the choke when it's cold, going to try that in the morning when it's pretty cool. Should I spray some lubricant on the linkage?

Sounds like you have an electric choke. Besides trying to get it adjusted, make sure it's not getting a constant 12 volts to the coil. If that's how someone happened to wire it up, it will just act like it's constantly warm outside. It will also drain the battery.

 

[yellowdog5]

Sounds like you have an electric choke. Besides trying to get it adjusted, make sure it's not getting a constant 12 volts to the coil. If that's how someone happened to wire it up, it will just act like it's constantly warm outside. It will also drain the battery.

Do you mean the coil on the electric choke? Will it feel warm all the time if it's hooked directly?

 

[Frankenchevy]

Does it have the black puck looking doohickey with three screws holding it down?

If so, first thing in the morning a full press of your throttle pedal should set(close) the choke plate. If it doesn’t close try this: mark the black puck at 12 o’clock so you know where you started, loosen the three screws enough to rotate the black puck until the choke plate just barely closes. Don’t burry it forward; in fact, go till it closes then back off a smidge. Then retighten the screws.

Btw, you’ll need your air filter removed to see what you’re doing. Only do this while it’s cold.

 

[Snoots]

Send a picture!

 

[HotRodPC]

Could the carburetor be draining back towards the fuel pump, so it has to be filled before it can start???

Yes, that happens with mine. The well plugs leak. It causes vapor lock in the summer time too and hard to restart if it's warmed up good. So when I let it sit for 2 or more days, I have to crank and crank, pause to not over work the starter, the crank and crank somemore until it's cranked enough to bring fuel back to the carb and fill the float bowl before it'll drop any gas.

 

[yellowdog5]

Does it have the black puck looking doohickey with three screws holding it down?

If so, first thing in the morning a full press of your throttle pedal should set(close) the choke plate. If it doesn’t close try this: mark the black puck at 12 o’clock so you know where you started, loosen the three screws enough to rotate the black puck until the choke plate just barely closes. Don’t burry it forward; in fact, go till it closes then back off a smidge. Then retighten the screws.

Btw, you’ll need your air filter removed to see what you’re doing. Only do this while it’s cold.

Thanks I'll do this as soon as it gets daylight.

 

[73c20jim]

Yes, that happens with mine. The well plugs leak. It causes vapor lock in the summer time too and hard to restart if it's warmed up good. So when I let it sit for 2 or more days, I have to crank and crank, pause to not over work the starter, the crank and crank somemore until it's cranked enough to bring fuel back to the carb and fill the float bowl before it'll drop any gas.

I believe GM, back in the day, had a drainage problem with some new cars, so they came up with a fuel filter with a flapper valve to prevent fuel from draining out of the carburetor.