Hi folks. I'm a n00b here so bear with me. I just bought an 86 Z28 two weekends ago. It's in stout shape overall, and I'm just doing some little tidbits of work. Here are the specs:

1986 Z28
Rebuilt 305, 4 bbl carb with about 65k miles on it
Edlebrock intake and carb
700R4 gearbox
Photos at... http://www.flickr.com/photos/horbins...7594049465638/


Just yesterday I started seeing the choke light come on then goes off when I am driving. It seems to be at random intervals, but always when I am on the throttle, not at idle or during braking. The motor is running solid and the car is not near a stall when the light comes on.

Should I be worried? Is there a problem in development or could it just be a fault in the sensor?

 

I dunno if ou should worry alot about it.. My choke is not even hooked up.. and that light comes on and goes off.... But i do not have any problems with the car. (I unhooked the wire from my choke because the choke itself is bad and grounds the circuit so the light it always on with it connected even with the choke off)

You might have a short in the wire that supplies power to the shoke, so when you are driving or whatever it hits metal and grounds which would cause the light to come on. and go off as the wire bounces

 

Try taking some carb cleaner to the carb. The choke may be sticking

 

Payed closer attention on my drive home yesterday. The light was on during the 2000 to 3500 RPM range of 3rd gear. I'll check the carb for any build-up. I've got some work to do on it this weekend.

 

That little light is the source of more confusion and misunderstanding that any other thing on these cars, I swear. It's wiring is far more complex than you may imagine and the choke element is only one of the things that can cause a problem. There's also a relay, a fuse, an oil pressure switch (some models) and the ALTERNATOR itself that can cause problems and light the dreaded choke light.

I've worked on these cars for years and I still defer to people who are better at electrical than I am when it comes to this circuit. Might want to check with some of the guys over on thirdgen.org and get a wiring schematic and some pointers.

Often, the problem has nothing to do with the choke circuit at all and it points to a bad alternator. Strange, but true.

Get some help on this one.

 

Thanks Damon. It's supposed to have a newish alternator (it even looks new), but I am keeping an eye on the alternator. The voltmeter looks strong when I drive, but the only time I have left the car sit for 36 hours without driving it (I have only had it two weeks), the battery had drained and I needed to jump it. Hmmmmmmmmmmmmmmmmmmmmmmmmm.

 

that actuyally does sound like an alt problem then i thing.. But the guy is right.. there are a few different things to that circuit.. I always did the work backwards method. starting from the choke and working backwards till i found the problem.. although never gotten any further than the choke itself on any of mine.

 

Nice car man; that things clean

 

It has only taken 6 months to figure this out, but here is the solution gang: the electric choke was simply out of adjustment. My neighbor saw me working on the car today (routine maintenence) and asked me how things were going. As we chatted about the choke, he pointed out the the choke on my carb can be adjusted by turning it in relation to the notches next to it. Sure enough, I backed it to a "close choke sooner" position and it has cleared the problem up. Essentially, the choke was adjusted for a PA winter where I bought it in January. When I got to the warmer DC-area climate with the choke set to stay open later, it was freaking out and trying to engage when the mtor was already warm.

 

and here i would have thought you would have tried to adjust it as a first step hehe..

 

Yeah, except I had no idea you COULD adjust it! I knew almost squat about working on cars when I bought this Z. I wanted to learn and have learned a lot! But Chilton and Haynes don't cover my aftermarket parts. Even when I looked up the Edelbrock 1406 manual, it doesn't refer to that ability to adjust. LOL So, I learn what I can from books, friends, neighbors, and this board. Part of the reason I sought out a carbed model: no computers made the thought of working on the car more approachable. I don't think anyone here would say that I couldn't figure out TPI models, but it was what I wanted to do. Anyways, it has worked out pretty well.

 

Hey man, nice car!