just went to start my 87 z28 carb'd all stock and heard a rapid clicking noise with key last position from start, car still starts and runs, i think the clicking stops after 30 seconds or so. took breather off and unplugged mixture control solenoid and it stops.

read mixed info here and other places (i.e. if it stops ticking thats when you have something to worry about, etc) well i've been running it all over the place and it just all of a sudden started, and it stops after 30-45 seconds.

is this bad? is it drivable? Should i ignore it? can i get a new one? what is the best approach

That's what it does.

Should click maybe 20 seconds, then stop, until you start the motor.

Nothing wrong with it.

First time you've worked on it?

Yeah it is. I just got the car but have been driving it all over the place. Removed the Air pump and got a new air cleaner and plug wires, and have just noticed it. So I've been under the hood a little bit and this is the first time Ive heard it...
So its fine then? I plan on ditching the quadrabog here in the next few weeks but will still need to drive it until then

Yeah, totally normal. Chevy decided to cycle that solenoid in the key-on position for about 20 seconds or so without the engine running.... no idea why. On Olds and Buicks they don't do it because it freaked out the little old ladies that bought those kinds of cars. They could hear the clicking and the took them back to the dealer with complaints. Chevy.... they didn't care. It's just what it does.

haha ok cool thanks Damon. Little off topic but what's a good streetable/user friendly carb/intake combo?

You already have one of the best carbs. The cc-Qjet system is fairly forgiving of modest changes in engine combo, even cams. Unlike an EFI system, a carb does most of the work for you in terms of matching airflow with fuel flow (as carbs have always done since forever). The ECM just "trims" the fuel mis based on O2 sensor readings at part throttle. At WOT the cc-QJet system runs just like any pre-computer carb would- full rich, with tuning based on the jets and rods you choose.

If you're planning on using a cam somewhere between stock and ~220* @ .050 duration the system will usually accomodate that with minimal complaint.

Now, if the wiring is hacked up, the ECM isn't working right, half the sensors are broken, etc. then yeah, it's often easier to just yank all the computer controlled crap off and go "old school" with a non-computer-controlled carb and distributor. That doesn't sound like the situation you're in, though (the MC still clicks, engine still runs OK).

What are you plans? Maybe I could be more specific if I knew where you stand currently and what you hope to achieve.

If the engine is solid and all the systems are working well right now there's not much to be gained by yanking off the cc-QJet and cc-HEI (if you do one you must do both) to replace just those pieces with non-computer-controlled units.

wow thanks for the insight. ok here's where i stand: stock 305/700r4 with 60,000 original miles. I like its driveability and mpgs as is, no need for a larger motor, just want some bolt ons for a little more power. was thinking cam, intake, etc, anything I can bolt on in the driveway.

One of the biggest things I have yet to put much thought into is the rear end gears, which must be at least 3.73's...cruising at highway speeds it is only taching about 1500rpms (lol) But like i might have mentioned I will be driving a lot so I cant kill my highway mpgs altogether.

So for now thinking motor bolt ons, I do have a little cash saved up, just thinking best power combo for price. Also simplicity is cool (like you said ditching the quadrajet means also ditching the factory distributor which may not increase power a whole lot) and yes my wiring is pretty good never been messed with other than me who removed some vacuum equipment, that's about it...

Edit: Oh im really after better sound, I had a 305 in a pickup that sounded nasty, but exhausts are much easier to do on a pickup. Exhaust is important to me, need something that is loud but not completely ignorant. Can I achieve this with just a muffler. looks like a dual set up might be challenging on this vehicle

I was just about to go searching for that same nosie. I also pick my my 85 TA and started cleaning under the hood and heard that clicking before you crank over the engine. OK then it's normal then, that answer that question.

The first thing you need for any 3rd gen V8 is a good exhaust system. In the case of your LG4 (low output) 305 that means EVERYTHING from the manifolds to the tailpipes. It's all little pea-shooter single 2-1/4" stuff right now. You need some shortie headers and matching 3" y-pipe, a 3" cat (if you need one for emissions) and a 3" cat-back system of your choice. That will set you back a few bucks right there, but the difference will be considerable even with no other changes.

You can definitely upgrade the cam. Do a search on the board about the "peanut cam" and you'll get plenty to read. I can't remember if your cam is a factory roller cam, but I believe it is. If so, just a stock L98 or LT1 roller cam will be a significant upgrade, reusing your existing roller lifters and pushrods- it has specs similar to the ealier L69 305 HO cam, but it's a roller cam. (If I'm wrong and it's a flat tappet cam in there now just get a Summit K1102 cam kit- it's a mild cam that will work fine with the computer controls but still BIG compared to the "peanut cam". It's about equivalent to the L69 HO cam, maybe just a bit more aggressive.)

Put some L69 "DR" secondary-side metering rods in the carb mounted on a "G" hanger (all changable out the top without opening up the carb), bump up the base ignition timing to about 6-8* BTDC (vs. 0* stock spec and make sure you do it by USING FACTORY TIMING PROCEDURE) and it'll haul a LOT better than stock. You can upgrade the stock intake to an Edlebrock Performer (available with EGR for emissions-compatibility and retaining the stock EGR valve) if you like as well. It help a bit from the mid RPMs on up. Ditch the stock single snorkel air cleaner and replace it with a 14x3 drop-base open element air cleaner while you're at it.

What you end up with is a motor that's about 1-2 notches stronger than a stock L69, which itself was no slouch.

Damon, should the solenoid continue "clicking" after the engine has run a bit? I m getting way to much fuel in the carb after the car warms up to the point of stalling. Thank you

the MCS should continue to cycle while the engine is running, otherwise it would have no control over the mixture.

from your question you may be confusing the MCS with the fuel enrichment solenoid on other q-jets?

I am pretty sure it is the MCS. I just have a problem with the carb dumping fuel after it goes into closed loop and stalling out.

Probably the float level would be my guess. If you think its the MCS unplug it while the eng is running to see if it makes a difference, but it constantly cycles, so its always "clicking".
It only stops after 10 or so seconds if you turn the key to run, but don't start the engine.
Thread is 10 years old btw.

when the MCS 'clicks' down it RESTRICTS fuel flow through the primary jets.

I see a pump squirt from the booster and nothing else out of the ordinary

The squirt is from the pump/plunger to the left (dr. side) of the MCS. What the MCS controls are the rich/lean mixture needles that are in the float bowl area. So you're not gonna see what its (mcs) is doing. If its clicking its working.
The MCS also "unrestrict" (richens) fuel on the up stroke. It only controls the primary needles, but its travel up/down is very short. Even if was stuck on the up (rich) stroke, i doubt it could richen the mixture enough to stall out the engine.

I saw in your vid you still have the "tamper" plug/s still in place. Plus the small plate/cover for idle/air bleed still in place. So doesnt look like its been foole around with. Any codes/CEL?