zcarz

Stock 84 Z28 LG4 carb with auto choke. Has never missed a beat. Carb rebuilt 2 years ago. Over the last few days the choke light is staying on and the choke is sticking on. To fix it I have to remove the air cleaner and flick the choke cam manually to pull the choke off, but the choke light still stays on. Very frustrating. Any ideas?

Apeiron

Is your battery charging?

sofakingdom

iTrader: (1)

That light might say "Choke". But in reality, it's the Alt light.

You need an alternator. That'll also fix the choke. It's not "sticking"; what's really happening is, it's not getting power to heat it up and make it pull off, because your alt is not working.

Air_Adam

The choke takes power from the alternator - reason being, if you leave the key in the 'on' position without the engine running the choke would open on its own without the engine running. This way, it only gets power when the engine is running, because the alternator is working.

But... when the alternator isn't working, the choke won't open. That is why the 'choke' light is really the 'alt' light. When the 'choke' light comes on, that means your alternator isn't working properly.

zcarz

Thanks for that, guys. I have noticed the volts have been down on the gauge over the same period. The gauge almost always sat above 13 however since i noticed the choke problem the reading shows it is now down on that, but I never made the connection between the two (alt light and choke on). Will check that out further in daylight. Battery seems to have plenty of power though.

Air_Adam

Not for long, if you've been driving like that much.

Also... don't use the alternator (once repaired or replaced) to recharge the battery. Depending on where the battery is at, it could possibly burn out the new alternator. Charge it with a real battery charger before you use it with the new alternator.

Mikz86TA

iTrader: (4)

Its been awhile since I had the 305 LG4 and Q-jet in the ol T/A, but I remember a similar issue. There is a relay under the dash that is for the choke. It was defective on mine and caused the choke not to work and had the light on. I replaced the relay and problem vanished. If you look under the dash just in front of the accelerator pedal, you will notice a black box assembly. It has two release tabs like the fusebox has for it to swing down. Once it is down there should be a couple relays and the chime module. I cant remember if the relay was green or white. It is a 3-pin relay. Has a 12v input (brown) from the C/H Fan fuse (20amp), a (brown) - feed and a (lt.blue) output to both the chole assembly and the choke light. The bottom of the swing down box will come off with effort to see the wire colors. Whichever relay has two browns and a lt.blue is your baby. Hope this helps.
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Incorrect...the volt indicator isnt on the same curcuit

zcarz

Thanks again guys. I haven't had a chance to have a good look at the problem yet but will try to over the next few days. Battery is fully charged but the car sits with a battery tender style charger plugged in when not in use, so that may be why the battery hasn't shown any lack of voltage. Will check out the alternator first and work back from there. With the low charge rate shown on the car voltmeter gauge I think the alternator is the most likely cause, but will get down to an auto electrican and have them put the tester on the alternator to confirm that. If not, will look into the choke relay issue.

NORTHSLIDER

iTrader: (4)

that same crap happened to me in my 79 t/a. the next day she wouldn't starts. new alt and good to go

zcarz

Problem fixed with new alternator. Good as new now. Thanks for the feedback.

327_TPI_77_Maro

iTrader: (8)

Mike, I think your post was the most helpful ever (to me). I have been chasing down the choke intermittently not working /choke light going on and off problem for a while, and it is NOT my alt. Car runs and charges fine. I know the relay is most likely shot but I never knew where it was. I am going to replace it now and hopefully be very happy! Thanks so much!

MPNolin

The Choke Relay is the green one. Got one ordered...

MPNolin

After reading the thread I thought I found my problem.
My Choke light is on. My Alternator was really noisy so I figured it needed replacement. I thought that would fix the choke light and choke not coming off. After a new alternator yesterday the choke is still not working and the light is still on. (much quieter running though)
I ordered the choke relay and it came in this morning.
I just put it in and no change.
Choke light still on and choke not coming off.

Udate
I saw this in another thread, sry...
I tryed the test suggested, 12v at choke lead, about 14v charging...
So I drove it to Advance auto, and they checked the alternator and they said its putting out good volts and amps.
Funny thing happened on the way to the store, the choke pulled off. I guess I was impatient waiting for it to warm up.

The choke light is still on but everything seems ok, should I be worried?

Air_Adam

Start the car and check the voltage accross the posts with the engine running. If its above 13.5V, then your alternator is working. If its below 13V, then its not working properly. If it is charging, let it run for a few mins and see if the choke opens. If its not charging, check the voltage at the brown wire coming out of the alternator. There should be something there (either 12v or 5v, I cant remember now), as thats the wire that 'tells' the alternator to start charging - if theres no voltage at that brown wire, it will not charge. If you find no voltage there, try having someone move the tilt on the steering column - that brown wire goes up the column, and often breaks in that spot. Battled that issue on a friend's car last summer. If no voltage is found, put power to that wire from another source and see if it starts to charge. It should if the alt is working properly.

If its charging, but the choke won't open, check the voltage at the choke wire, if theres nothing there or its significatly lower than 12V, then something is wrong in the choke circuit. Follow the choke wire and look for cracks, breaks, rubbing through, etc. If nothing is found, I'm 99% sure there is a fuse for the choke circuit - check that. Make sure the linkage isn't all gummed up with dirt - spray it off with throttle body cleaner (less oil in it than carb cleaner).

If you have an alternator tested, take it to a real alternator/starter shop, where they can actually tell you what the alternator is doing. The testers they have at places like AutoZone usually will not give you numbers - its a pass/fail sorta deal. It will not tell you what kind of amps it putting out at what speeds, etc. A real alt/starter rebuilder shop can tell you that stuff.

MPNolin

The choke is working and pulls off when warmed up now

I had the brand new alt checked (B&M Automotive) and it was given a thumbs up... Normal charging.

The choke light is still on, dim but still on...

I do have a "ALT" light in the cluster. I don't rember ever seing it come on.
The "OIL" light comes on at start-up for a second
I've never seen the "TEMP" light come on...

Could the ALT lamp be burned out? Could this be causing the choke light problem????

Fatal213

Just had a question might be dumb, but I have a 89' iroc the choke light comes on when I put the car to the on position and the car just wont start will a bad alt cause the car not to start ? I also have a code 33 any info would be greatly appreciated

Apeiron

An 89 IROC never had a choke light. Someone's changed your bezel.

Fatal213

Wow thats a shocker thanks for replying but I did manage to get rid of it by just adjusting the tps and I also adjusted the timing so now Im just hoping that did the job

Oldtin4me

This happened to me and I'm still having issues with my car but was unaware that if you pull the fuel pump fuse under dash it also cuts the choke off and leave the light on. the reason I pulled the fuse was because it was way overloading the carb with gas I know it probably need to seal up the holes on carb for adjusting because of vacume leaks.my car has 2 fuel pumps one in tank one on motor (by thee way I have 87 Z28 with 305quad cc) but can't really go down the road it does doesn't really want to stay in if you stay accelerated for more than 20 sec or you just cruise along in overdrive. I am getting so sick with this car I went and got a different carb today to try and get it ruining but after reading these posts about join the cc I reconsidered it but I really need to know where all the adjustment need to be for bench or factory spec like the 2 screw needles on the very bottom of carb, the mixture screw ,the one on the right side of carb (what exactly is that doing when I mess with that) the 2 on to in front of mixture screw I know there rich and lean but everything has got to be way off. I also bought a fuel regulator to get it to stop over loading of carb with the the electric fuel pump fuse in and just as simple ss outing the fuse in the choke light went off it. how much psi should these things have