1980 911 SC problems

[Hill3312]

Just moved to San Diego and found out my neighbor had a 1980 911SC he was thinking about selling. The car is in beautiful shape with no rust at all, and has a stack of paperwork including a complete rebuild less than 100k miles ago. Allegedly all It needed was an alternator. The car had been sitting for 5+ years so I knew it was going to need more than that.

I replaced the plugs, drained and filled with new gas, changed the oil (careful not to overfill), installed the new alternator... And got the car started today.

- here's the problem(s) ... Car smokes like it's been treated with Seafoam. It responds late and poorly to throttle input. Wants to stall when you try to give it gas, barley revs. Bucks and misses like crazy when trying to drive down the street.


I'm guessing the whole ignition is going to have to be worked through... Wires - CDI - cap and rotor - coil. What else should I consider doing? The smoke is of particular concern to me.

[yelcab1]

You should consider driving it for 30 miles at night and let the oil burn off first. Then, reassess.

[Hill3312]

Originally Posted by yelcab1

You should consider driving it for 30 miles at night and let the oil burn off first. Then, reassess.

That was my intention earlier today, but it's simply undriveable. Barley made it 100 yards down the road and back. Extremely poor response to throttle input.

[timmy2]

Take your time and read these...

911 CIS Primer - Index

CIS Troubleshooting for Dummies

[tista]

Check your injectors - cheap and easy fix if their clogged.

[emac]

The first next thing I would do is change the gas filter making sure the arrow points in the right direction
Ernie

[T77911S]

sitting? plunger stuck in fuel head
control pressure problems

[Targalid]

Good advice above: run it for at least a half hour to clear the fuel system of old deposits. My favorite recipe is a quart of ATF per tank of fuel and a bottle of fuel injector cleaner, then drive it. My car had sat for a similar amount of time (smoked like crazy and ran like crap) and this recipe worked for me. In the PRC you want to follow the advice given above to the letter, drive it at night.

[Jdub]

If the battery is not new, be sure it is very good and at fullest possible charge. Fuel and air filters as well and oil filter (you do not mention this). Review your work - all plugs very snug in their respective slots? No plug wires attached to incorrect plugs? Get a timing light on the engine and check. Open the cap from the distributor and pluck out felt piece - soak in machine oil and put back in, adding just a judicious drop or two.

You want to be sure that, when you do run all the crap out of the engine/CIS, that you are not running on incorrect attachment or spec that could damage engine.

How was it running when it was parked?

[bourgeois911]

I would also check to see if the distributor advance is frozen after all that time. That would make it run like a slug.

[wwest]

Ignition/timing....

[scottrx7tt]

You could have a busted/cracked intake

[Hill3312]

Hey guys!

Went out today and picked up some Marvel mystery oil, and some more 91octane. Filled the tank above half, added 1qt of Marvel to the engine oil and a few oz to the gas. Let the car run for 30 mins after double checking spark plug order and connections.

After fumigating the neighborhood and getting nasty looks from people driving by I decided to take it out once more. The car ran smooth with good power! Best part, minimal smoke by the time I got back to the garage!

Thanks for all your input!

[Discseven]

+1 on changing fuel filt and cleaning injectors. (Search: Mr. Injector. Has good reputation among Pelicans.) 5 years sitting... if gas was in the system which one must assume it was, all that is potentially syrup in the system now... clogging the pressure the engine needs to run right.

Did not read all posts so perhaps missed answer to this question. What color is smoke?

[targa80]

As others have said, you really need to go through the fuel and ignition system since the car has sat with stale gas and oil for 5 years. Also, acquire a set (6) of plastic baby bottles( Walmart/Target) cut the tops of the nipples and poke each injector into each. Buy a fuel pressure test rig from Harbor Freight. The baby bottles will allow you to see the spray pattern on each injector and/or if they are clogged, dripping fuel when closed. The test rig will allow you to check your fuel distributor system pressures and verify if it holds residual system pressure to spec when shut down. If you do a search there is plenty of info on how to perform these tests.