Compression Test questions

[LeonV]

And....keep that hair away from the fan....

Good point. If my hair is close enough to the fan to be dangerous, I've got bigger things to worry about.

Avoid loose-fitting clothing and anything with draw strings as well.

[rcb280z]

I didn't see anywhere that you checked drive belts....have you? I had a alternator put out a high pitch squeal occasionally if the humidity was high along with a weird belt noise. Worth a shot.

[FastWoman]

Hi Jenny,

Wow, you've been moving along on this thing! I've been largely MIA because of a dock we'll be building. The contractor is ready to move on it, and I've been scrambling to order stuff and finalize the last design details. I'm fried!

I think the recommendation for an engine stethoscope is a good one. You can buy one very cheaply from Harbor Freight, and it will work far, far, far better than a long screwdriver. Moreover, I think there's a very real safety issue. As a neurobiologist, I'm always cognizant of the example of Phineas Gage (whom you can google). Of course most people don't fare as well as he did after having long metal shafts launched through their skulls! Even being punched in a rather fragile area of your skull with the butt of a screwdriver handle would not be a good thing. A stethoscope is much safer, and the sound is far, far clearer. Personally, I would suspect a bearing, although I didn't hear the noise that well.

As for predetonation issues, you really need to get a handle on your vacuum advance. If it seems sluggish or stuck, consider that it can advance on engine deceleration during closed throttle (when vacuum is highest) and then hang there. It's almost useless to set your timing when your vacuum advance (or mechanical advance) is sticking. Your timing could be almost anything.

Personally I'd go for the rebuilt AZ distributor. There are aftermarket distributors (better ones) if that doesn't work out. Frankly the distributor is the only quite-bad component of this engine.

Your AFM cover: There shouldn't be any noises from the potentiometer chamber with the cover removed, nor should you hear any vacuum noises. The cover simply keeps the innards clean. When you're completely finished working on the innards, you need to clean away all the old caulk, squeeze out a rather thin bead of new caulk (I like 5200 black) in the cover's groove, and squish it onto the AFM. Let it cure overnight before driving. But whatever you do, don't let the cover fall off! I have no idea how you would replace it!

[Jennys280Z]

My door was ajar (beeping) on some of the video, sorries!

rcb280 was right again. My fan belt tightened on the adjuster arm about 3/8" of an inch when I pulled it back hard. I thought it was pretty tight already, but the torque-ier motor demanded a tighter belt. Playing the sound over and over again, I noticed it coincided with the throttle but slightly lagged the throttle so it was related but not directly related. Never heard a belt make noise like that before (it was like nails on a chalkboard to me when I heard it ) but I could visually see it slipping thanks to the white markings on the belt when I was looking at the timing again. Sorry for making so much drama over not much of anything. I was really worried though so give me a break.

Thanks Fastwoman! I'm going to use the same product on my AFM cover too. I'm glad there's that nice metal base the AFM sits on or that cover would be lost on the side of the road somewhere by now. Good luck on your dock. Is this for at the end of your backyard? Looks like the two main options I can see for a distributor replacement are A1-Cardone and Autozone and they're around the same price either place. I'll check the vacuum advance again since I did it all of a couple of years ago and see if I get a similar (believed bad) result.

Eurodat, thanks for taking it out of the box. I looked closely at everything I could find that was loose under the hood, and found the throttle linkage boot at the firewall as dry as toast. Just hanging on there in tatters, so I pulled it off. Not sure how I didn't see that before but it's amazing what you can see if you look hard enough lolz. Now I have a gaping hole at the firewall. I'm guessing it's to keep dust and dirt out but I'm not sure how important this is to replace (much less how the heck I can even replace it without taking the linkage apart).

Thanks for helping resolve all my issues guys; you're the best! xo

[FastWoman]

Jenny, I believe the AZ distributor is rebuilt by Cardone. The one I got was fine. However, I understand they sometimes bend the shaft a bit when they rebuild them, so be sure to check for any wobble.

It would be worthwhile putting on a new boot. It's not a hard job taking apart that part of the throttle linkage. The risk, without a boot (and similarly with any other holes in the firewall) is that carbon monoxide from an exhaust manifold leak can blow into the cabin.

[rcb280z]

Jenny, glad to have helped. This forum has helped me a lot as well. So I'm pleased to have returned the favor.