1980 911 issues

1upracing · 08-15-2006, 07:28 PM

I just picked up a 1980 911 that has been parked since 1996.

Issue is backfiring at low RPM and low power. It runs better at higher rpm but not optimal. Sometimes it runs perfect for about five minutes and then its like something opens or closes and it runs like crap. This morning I was going to take it to the shop and made it about two blocks when I heard a loud squeal. I turned the car off and checked engine compartment. The smell of rubber and a very hot fan belt pulley. I also noticed the fan had a little play in it. Just before the loud squeal I also noticed a wining noise and alt light come on.

Is the alternator/shaft bad. and would this have also caused the backfiring.

ruf-porsche · ruf-porsche's Garage

Wow a newbie. Either the alternator bearing is shot, or the a/c compressor is shot. See if you can turn the BIG fan that cools the engine. If you can't than the alternator bearing is shot.

Buy some techron and add it to the gas and run your engine. See if it doesn't fix the problem after a couple of tankfull of gas.

Kemo · 08-16-2006, 06:28 PM

my 78 kinda did the same thing when i first got it...my squeal was from the old A/C compressor that didnt work anyway. so I removed the A/C belt.

Hopefully your alternator isnt wasted. After I replaced all the injectors, filter and the green wire to the distributor, my car actually started running ok...

rhaas · 08-17-2006, 05:02 AM

I have found that the WUR on these cis cars get gummed up after sitting for a while. I generally take the fittings out and wash the in port if the wur to remove varnish from the filter screen.

Doug&Julie · 08-17-2006, 09:30 AM

Correct me if I'm wrong, but won't a loose alternator belt slip, thus causing the squeel? ..and won't a loose alternator belt make the alt light read as low and come on? ..even if the alternator is still good? I would think these things before a bad alternator / shaft.

And yes, after 10 years of sitting, the whole injection system probably needs a good cleaning!

kwm · 08-17-2006, 09:44 AM

The housing that holds your alt could be cracked and broken like most of them are. I think it is magnezium and some but most are too cracked to be welded. If the housing is too bad it could not be allowing enough tension on your drive belt. These alt housings are damn hard to find. I know Porsche no longer makes them and not sure any good after market manufactures have stepped up to fill the void. Look at the bottom of your fan housing they often show nicks from where the fan starts hitting the bottom b/c when you or the PO gassed the car hard if the alt housing is failing it would have started pulling the fan downward into the shroud. Good luck and turn around and get it back home where you can fix it yourself w/o paying the cost of your mortgage payemnt to the shop you are headed toward to get this fixed.

Grady Clay · 08-17-2006, 10:26 AM

Welcome to the Forum.

You will find a lot of help here.

I agree that it is worth disconnecting the A/C belt first. It is easy and you have to remove it anyway if you need to deal with the fan/belt/alternator.

If an alternator bearing fails and the shaft stops turning the belt squeals and the red light comes on. Same if the housing were cracked. It may not be that the alternator is electrically damaged just that it needs new bearings. You can do this yourself, have a commercial auto electric alternator shop do it or buy an exchange rebuilt alternator from our host.

In any case, use the Forum to help you diagnose the problem.

I agree that 10 years storage is too long to expect the fuel system to still correctly function. Try cleaning and when something goes awry, clean some more. Don’t start throwing new parts at it.

The fuel tank is a good place to start. Remove the fuel level sender and make yourself a long “swab” to wipe the bottom of the tank. See what you find. It is worthwhile to siphon all the fuel out and remove the screen filter from under the bottom of the tank. Yes, that great big Allen hex. Depending on what you find, you may need to have the tank cleaned.

That is only the beginning. Every component in the fuel system is suspect of having gummed up fuel residue causing it to malfunction. The good news is most of that is fixable with patience, fuel additive (Techron) and carb cleaner.

You will want to replace the high voltage ignition components (cap, rotor, wires, plug connectors). Ten years is too long. Even the ignition transformer is suspect. Kemo is correct, look at the green wire at the distributor. That commonly has distress at the distributor.

Brakes don’t like inactivity. It is not uncommon for the master cylinder to fail after a car has set for long periods and then be driven. Check for this as you don’t want to suddenly find yourself with NO brakes. The old brake fluid should be replaced, the pistons in the calipers cycled and the flex hoses replaced. This is a good opportunity to inspect the pads and rotors. If you are prepared, it is a Saturday job. All of this is nicely presented in: Dempsey, Wayne R. 101 Projects for Your Porsche 911, Section Six, available from our host.

Have I overdosed you yet?

The point is to keep you out of trouble and let you enjoy your 911. The usual focus is DIY with strong emphasis on your understanding everything so you can communicate (to the Forum or a tech) the issues. You have a wonderful 911 but it is 26 years old and has been resting quietly for 10.

Doug, it sounds like the alternator suddenly stopped turning. With a loose belt, it will squeal just after starting as the alternator goes to full output to recharge the battery from starting. Occasionally one will squeal when you turn on the headlights.

Best,
Grady

kwm · 08-17-2006, 10:33 AM

Listen to Grady and DO NOT take your car to a shop in it's present state. Even the most respectable shop will hit you with a huge list of things that need attn: since this car has sat so long. The thing is most of it is TLC which it sounds like something your car has not had in a long long time if the PO wasn't even respectfull enough to drain the fluids before parking it. Do you know what bad gas smells like? If so that is the first step. If your car smells like bad gas, and you can smell it 30 feet away, start wtih what Grady is telling you. My car was in the same boat as yours and unfortunatley the interior still smells like bad gas to this day.........

Doug&Julie · 08-17-2006, 10:36 AM

Quote:

Originally posted by Grady Clay
Doug, it sounds like the alternator suddenly stopped turning. With a loose belt, it will squeal just after starting as the alternator goes to full output to recharge the battery from starting. Occasionally one will squeal when you turn on the headlights.

Ah, thanks for that. I'm learning...

Motorhead-45 · 08-17-2006, 01:24 PM

You could always post your location and perhaps you'll find a local Pelican willing to lend an educated ear/hand to the diagnosis....especially for a newbie!

kwm · 08-18-2006, 04:10 AM

I bet local independant Porsche shops HATEEEEE us. Talk about a shop's wet dream......a guy drives up with a Pcar and says...."I just bought this Pcar and it has been setting for 10 years can you fix it please"....$$$$$$$$$$$$$$$$$$$$$$$$$$