RED HOT

Upon recharging my airconditioning system a few weeks ago on my 78 911SC I came upon a strange problem. When I was feeding the freon in I kept the idle up to 3500 rpm as told by the people at Performance Aire. It fed in, but when the Oil temperature guage read130-140°C it started to miss and sputter. The smell of rich mixture came from the tailpipe. I was getting it recharged about three hours away from my home so I just bit my lip, let it cool down for an hour, and then started it up and kept charging until it sputtered and died again. I finally filled the system. Waited overnight and then drove home. The car ran fine. The ambient air temp was around 48° that next day. That was about 6 weeks ago.

Now this week I noticed a squeal, like a belt, at start up. I checked the belts for looseness. I sprayed belt dressing on them. THe squeal went away after a minute.

Then I noticed a few days ago that it was missing at idle while I was driving during lunch. I parked the car and opened the hood. It had that rich fuel smell again coming from the tailpipe. I was at work and had to get back. I would keep an eye on it.


Today 4/7/99 I was on the commute home. It was about 78° F high humidity. AC was on. It began missing at idle right after warm up. ( It doesn't warm up very well either, jumpy, surging idle at start up, low idle 600rpm for about 6 minutes.) It ran OK in the upper RPM ranges and I vowed I would look at all of the plug wires when I got home.

I commute about 45 min. in stop and go traffic. At about the 44th minute it began to cut and miss out like it did when I put the freon in. I was about a 1/4 mile from my house. I looked at the temp guage. It was above the mid range mark half way between the mid mark and redband. I put the accellerator down to limp the last 8th of a mile. It was sputtering like mad. It started to smoke when I pulled in the driveway. Blue smoke from oil residue was fogging out from under the car. The neighbor kid came over and said " Your Car Is Smoking". I opened the hood and smoke was being sucked into the fan. I went back to turn the ingnition off, and saw that my Catalytic converter, exit half, was red hot. My muffler was red hot. Yellow hot in some places. I Knew I was going to have a fire any second. Stuff was dripping on the cement. It was the bumperette oozing. The rear valance was turning gold (silver car). My dog was barking his head off. I told him to, shut up stupid ****, right in front of the neighbor kid. I looked back into the compartment and it was sizzling and smoking and I saw something start to crackle. THEN A SMALL FIRE STARTED. I dashed for the extinguisher. The button BROKE OFF and I couldn't use it. I ran to the garden hose. Turned it on and ran back. And Doused the fire out taking the risk it wasn't an oil fire. WHAT A MISTAKE IT WAS TO DRIVE THE CAR.

It turned out the burning thing was the rubber air seal in back.

But guess what? 20 minutes later I started it up and pulled it into the garage. No miss, no sputter. 950rpm idle with smooth throttle response.

Anybody have any Ideas on how I can fix it? What could it be? WUR? Ignition? Both? I think it is ignition. Wires? Coil? What tool do I need to buy to diagnose it?

It is my hobby car. I work on it. I always try to diagnose exactly what is wrong with it before I take it anywhere else either.

Any help is greatly appreciated

First thing I always do when trouble shooting is to initially check out whatever I did last. In this case that theory may apply. Disconnect the air belt and see if the problem goes away. If it does, the air compressor is it.Did the squealing go away when you sprayed the belt? If it did, maybe the compressor is seizing up and loading the engine.Are you supposed to include lube with an ac charge?. Ned

I agree with the above post. Check the compressor. BTW-Belt dressing only makes the noise go away, not the problem. They should ban that stuff.

You probably have a belt/pulley/compressor problem that is a drag on your engine causing the overheating. Bite the bullet and take it to an A/C shop. They can recycle the freon and fix your problem.

I agree with the above post. Check the compressor. BTW-Belt dressing only makes the noise go away, not the problem. They should ban that stuff.

You probably have a belt/pulley/compressor problem that is a drag on your engine causing the overheating. Bite the bullet and take it to an A/C shop. They can recycle the freon and fix your problem.

You may have overfilled your system with freon this will cause a drag.Also when you recharge your system you must keep your rear decklid down or it can damage your a/c.
When the system is totally evacuated you check the oil level in your compressor with a dipstick.

[This message has been edited by jryerson (edited 04-16-99).]

I took the car to a service shop. It was running rich in mixture-somthing like 8ppm CO with the air pump dissconnected. The rich mixture lingering in the muffler and after the catalyst ignighted like an afterburner and superheated the catalyst and muffler. I suspect when my car's mixture was adjusted it was tuned with the air pump connected. It ran great all winter but guzzled gas. When the weather got hot it raised the temp up enough to light the gas laden exhaust like an afterburner. I was geting only 315miles per tank. I got 370 miles after adjustment. Thanks for the help though. The generator belt was the squeaky culprit. It was replaced.