82 SC dead

Hello everyone,
I got a 911 question, hence why I'm here and not in my normal 914 BBS

A friend has an SC and was driving it home at about 50 mph when it just died. He towed it home and cranked the engine only to receive a big boom (backfire). He decided to stop and let me take a look at it, Im a little more capable at this. My question is, any 911 tips of where to start? I'll check spark and fuel first, and work my way around just wondering, no hoping for some secert ideas.

Thanks everyone here, you guys always help

Kevin

I'm afraid that may have been an EXPENSIVE backfire! Ask/check to see if the CIS airbox has a pop-off valve installed. If not, at night, remove the air filter cover and filter element. Check with a small AA flashlight for cracks in the airbox housing by shining the light on the backside of the airbox and look for visible cracks noticeable by light leaks. The cracks may be immediately noticeable in daylight or they may be hard to find, hence looking in the dark! Airboxes plus the 'required' pop-off valve are about $300 from Pelican! If/when that is fixed, you can begin investigating the cutoff problem.

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Warren Hall
1973 911S Targa

If that doesn't pan out, take a look at the timing chain and see if it's still where it's supposed to be. If it has gone astray he might've damaged valves in the process.

Hopefully it's just something as simple as the spark plugs not being sparked at the right time - is ignition electronic or mechanical?

-Boyo

When looking at the spark see that it is "big fat, white, and happy" as DD would say. On a freind's 89 930 (one of the only completely stock cars I've ever worked on) the plugs had spark but even at night it looked weak. More blue than white. Also the CDI wasn't making much of a noise. The CDI box makes a high pitched whine. If either the whine isn't there or the spark is weak it "MIGHT" be the CDI. Of coarse CDI boxes are $$$$ the way we figured it out was to swap in a know good unit. I know, back yard inginuity at it's best, but I don't know of any other way to test the unit.

Also the regular stuff, listen for a fuel pump and check that the fuel pressure is proper.

Well, here is what we found. An airbox that had exploded (buying new one and valve), and a distributer problem.

The shaft of the dist moved all around, this free play caused the cap to eat away at the roter which eventually caused the hole thing to quite working. Weird thing is we were getting spark, but it looked like that distributer would never have worked.

Buying new distributer, and fun parts to go with it. Any ideas on why it failed?

Thanks everyone

The bushings in that distributor can be replaced if there is no damage to the shaft and body. Only way to tell is to disassemble ... not a difficult process. Good luck!

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Warren Hall
1973 911S Targa

I'm still waiting for Warren to give someone anything but the best advice. Distributors for our cars MUST be spendy. Bushings are truly pocket change, if the shaft and body are still straight. Distributor bushings should be nearly a regular (after years of service) maintenance item. If it were me, I'd DEFINITELY pop the distributor out, put in new bushings, and probably solve the problem.

TIP: if you put the bushings in the freezer and the body in the oven, the (sometimes delicate carbon-impregnated) bushings may practically fall into place, avoiding the struggle to tap or press them into place. Be ready with a properly sized mandrel (socket) though.

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'83 SC

All of the Bosch distributors I have disassembled have a 'chunk' of felt inside the shaft, right underneath the rotor, and it is intended to be oiled on a regular basis, hopefully once or twice a year ... with pointless distributors, my guess it didn't get the oil it needed! That is one of the things on a dealer service checklist that gets skipped by owner/mechanics, and local garages in a hurry!

My paper service manuals stop with the '76 model, and my microfiche is supposed to cover all the way through '83, so I will take a look to see if there are any changes noted in the distributor for an SC. All of my previous Bosch distributors used a plain oiled-bronze bushing, available at any major bearing supply.

Thoroughly DEGREASE the distributor body BEFORE putting it in your oven or your next baked chicken might 'smell' like an old engine part! Wives generally don't like ovens or food that smell like petroleum products, and I don't either!!!

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Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 05-03-2000).]

Thanks all. Heres an idea for you people putting things in your stove. You can go to a local store (WalMart) and get a $30 toster oven, or find one in a garage sale ($5) and use that. Just keep it in your garage. No need to clean parts, if it catchs on fire, just put it out. You don't need to worry about poisoning someone from the gunk in there because you wont cook on it. Well, hope this helps some of you.

Kevin Germain