I have read many posts here about Electric Chokes, Choke heater relays, fuses, GM wiring the choke through the alternator, or alternator through the choke light...I have detailed files. And schematics.
Here is my question, in a series of events, which gives no illumination when I search for it...

1. Car operated normally.
2. Jump started car.
3. Weird buzzing sound under dash while running, and flickering choke light...alternator ok..C-H fuse ok, unplugged electric choke and car runs ok. ECM gives no codes.
4. Emissions due...had to replace O2 sensor, PCV valve, and put a bigger washer into the EGR. Took choke bulb out of dash so guy doesn't see it...he thinks buzzing is electrical "or something".

5. Buzzing gets louder, and car has zero get up, PCV valve clicks like crazy when I step on it.
6. I replace with new (junkyard new) choke heater relay, and brand new choke element, and hook it up. Same. Buzzing is louder. ECM still gives no problem codes. just the old 1-2-1-2-1-2. Which tells me at least the ECM is ok.
7. When starting cold, there is a popping/clicking sound from the left of the engine until it warms up, not PCV. I think this might be either the new O2 sensor grounding, or the blue fuel mixture doo-hicky on the carb. Replace fuel filter on a stab at fuel starvation.
8. As a last resort, I just crank it up with the green choke heater relay taken out. BAM. **Everything is better than normal**, with great pickup, and it will spin the big meats again...

So...

Does the missing CH relay trick the ECM in to giving the carb more gas?? Or is it bypassing the relay somehow, and still using the choke (and its cut-off)...because without a choke element it didn't run this good, and cold starts are not a problem....

I know it's long, but I am a detailed person, and I want to give some of the seniors on this board something to chew on...

 

I forgot to mention...the amp gauge is whack-o...sometimes it's fine, sometimes it drops to about 10, now it is completely dead (CH relay out)...I know it's related, and my alternator is fine.

 

Whatever it is it won't have anything to do with the ECM. The ECM has no insight whatsoever into the operation of the choke circuit. The buzzing from under the dash is the choke heater relay opening and closing quickly, which explains why it went away when you unplugged it.

Why do you say your alternator is fine? What you call an "amp gauge" is actually a voltmeter. I don't have a schematic in front of me, but I believe it should show a reading even when the C-H relay is pulled out.

 

I think you've answered your own question. It seems your problems started after you had to jump start the car. Why did you have to jump start it? Did you leave your lights on, or did it just decide not to crank over one morning. If you didn't leave the door open or the lights on, then how did the battery drain?

If you didn't leave somethign on, then the alternator is going bad and is not charging the battery. It should be checked by a parts store and replaced. The buzzing you're hearing inside the car is the choke heater relay. With the key on and the engine not running the relay is energized, which shuts off power to the choke. When the alternator is not spinning, the brown wire goes to ground through the voltage regulator in the alt. This brown wire goes to the other side of the choke heater relay. When the engine starts, the brown wire from the alternator now has 12 VDC on it since the alternator is outputting power. Now there is 12 VDC on both sides of the choke relay and their is no current flowing through the coil. The relay then de-energized and swithes the choke heater on.

Now when your alternator is going bad, then its output is not quite 12 VDC. So what happens is the voltage flucuates in the brown wire (and on your gage) and causes the choke relay to open and close many times per second thus causing the buzzing noise.

My recommendation is to put the relay back in (or else you're choke will never work) and to go have your alternator tested. My money is on the fact that the alternator needs to be rebuilt or replaced.

Good luck,
Dave

 

I guess the simplest explanations are the correct ones...I was in denial about the alternator going bad..
I will replace it and see...it's been tested before, but it's from 1989, so I think it might be due...
Since it ws tested, I wrote it off and hunted elsewhere...

What would happen if I wired a switch into the choke heater relay's connection, and just turned it on and off when I wanted to...like an old 40's car?