1980 Camaro Z28 Running Bad, Tune Up Questions.....

Friend of mine has a 1980 Camaro Z28. 350? (either a 350 or 305, I couldn't tell for sure)

Its running not as good as it used to so he asked me to come over to help him tune it up. I just have a few questions.

He's got a Edelbrock carb on it. He says its a 650CFM. I was hoping someone could help me find a vacuum diagram for this specific carb. The thing has vacuum ports going all over the place, and I'd be willing to bet some are going to the wrong spot.

Next question is the distributor. I have a timing light, I went over to his place a couple weeks back and threw my timing light on it. (firing order on the LIM lists 18436572 so I put the light on plug wire 1) The tag down on the crank shows numbers -6,-4,0,4,6. I clamped off the vacuum port going to the distributor, started the car and shined the light down at the crank. The timing mark was WAY off the marks on the tag. When I turned the dist one direction, the mark moved farther away, but the motor smoothed out a little. Then I turned the dist the other way and the mark moved down closer to being on the chart. When I got to 4 degrees, the car barely ran and stumbled around a lot, and no way was it going anywhere near 2 or 0 without stalling out. So I just set it back to where it was and left it for now.

What is going on? Is the distributor off a tooth, or did the cam/crank timing jump or is there a lot of slop in the timing chain?

Another question is I have never seen this type of distributor before. Its not like the type on tbi chevy trucks, nor is it the standard GM HEI type that locates the coil in the center of the cap. I even looked it up on rockauto and the pictures are completly different, so I don't think he's got the original distributor. I will try to get a picture of the dist, and a model number if someone can help me with directions on how to install it on number 1 and time it.

So there are my questions, vacuum diagram for the edelbrock carb, distributor timing. Sorry for the long book.

Thanks!

Any Takers?

Here are a couple pictures of the Carb. And you can see the dist in the background, looks like its just a regular dist with an accell coil so I should be able to figure that out.

http://img682.imageshack.us/img682/3486/1000436q.jpg

http://img806.imageshack.us/img806/324/1000435.jpg

First thing, the dizzy is not stock. Vacuum advance distributers went away long before '80. Point being, the timing tab will probably be of little help.

Second, that carb is a wreck!

First thing, the dizzy is not stock. Vacuum advance distributers went away long before '80. Point being, the timing tab will probably be of little help.

Second, that carb is a wreck!

Uh oh, and uh oh.

How can I time the ignition then? That probably explains why the timing mark on the crank was so far off.

And explain "wreck", do you mean junk, or just messy. :rofl:

Is it fixable, or just junk?

I told him to put the quadrajet back on, but he wont do that. Or was this camaro a tbi system?

Being born in 1986, This car is long before my time, so sorry for the dumb questions, and thans for the help.

Well, it's been quite a few years and some memory loss in between, but you were already on the right track in trying to set the dizzy. Remove the vacuum advance. Install a vacuum gauge on a manifold vacuum source that does not effect engine performance. On a carb, you have 2 types of vacuum. Manifold vacuum and ported vacuum. Anyway, advance the distributor til the engine smooths out and starts to get a LIGHT ping (spark knock), then back of the advance to elminate the knock while maintaning a solid vaccum reading. It's a trial and error process with no timing tab, however, after dealing with it for a while, you don't even find yourself using a timing light anymore.

As for the carb, it's a pig and just by glancingin at the pictures, probably has quite a bit of carbon deposits in every orafice and passage, and all over the throttle blades pivot points. To say anything about clogging the metering jets and altering float bowl operation and accelerator pump. In one picture it even looks like the floats are infact overfilling and leaking. It also looks like some of the vacuum hoses have atleast a decades life on them. I'd say the carb right now, is the main culpret in the engine's poor performance.

Thanks. I will give it a shot, but it may be a lost cause.

So, how would a person time this car if it had the original distributor? Would I have to unplug a wire, or????

Because we may head out to the junkyard for some parts for my car, and if we happen to find the stock dizzy, we may pick it up.

If you revert back to the stock distributer, you open a new can of worms with the carb. Although it is very basic, the electronic quadjet works off a feed from the ignition module inside the GM HEI distributer to an en extent. Also, the stock HEI has a stand alone spark control module that's probably been deep sixed.

I'd look up on Edelbrock's site for rebuild kits and instructions for the carb. It's not hard to do, but to the first timer, tuning it back together can be a challenge. If you're not up to it, there are places you can send it into for a rebuild that will cost a couple hundred bucks. I'm also curious to know how the owner has the electric choke heater hooked up, I'm assuming on a toggle switch? If not and it's running off a battery hot at all times feed, that's another problem goofing things up, which wouldn't surprise me as the whole install looks like a novice hack job.