911sc 82 advice on tuneup

[premdes]

Greeting to all
I have this declining Problem that I can't seem to find. I think it's moving around on me. As soon as I get close to solving it, it moves! Maybe paranoia at this point.

It started with the car hitting a wall at intermitten acceleration. Usually cold engine and cold sit it was fine. Then a couple weeks later all accelerations bogged down. (catalytic converter style). Then noticed after a few more weeks, it wouldn't start after stopping at a store. Go to jump it and my battery would be so hot you can hear it bubble. Then came the hard starts. Needless to say it was garaged for a long after. Last winter I tried DIY to replace all injector seals, checked each wire for spark, new plugs, valve adjustment and replaced all small vacuum hoses.
Took out WUR, cleaned it and inspected it.

However,
Found a floating vacuum hose with a screw in it from previous service I guess on right side of engine by cylinder 6
Found OS plastic shield split in half (the orange thing).

Have no idea how I got it started after 25 cranks, drove it to mechanic to fix the issue and tune it up. but Porsche shop just changed my belt and tuned it supposedly. Asked them to do parasitic test and they found nothing lol. I ended up driving it home 60 miles away And barely made it home with backfire and would shut off at lights so I had to keep revving .

Only way I can start it now is to have someone crank it while I lightly keep the air plate up just enough to keep it going.

Boch unit seems to whine loud, air plate hisses and squeals.
Have not checked fuel pressure (need direction)
No leak down test (need direction)
And I just learned from other posts about the test port and how to hook it up. So I will need to further study this and make an attempt.

I need a solid list of steps to check and rule out possible causes. I will write down values and results one I get some direction and post it back up.

Thanks in advance

Amir

[Trackrash]

Sounds like more than one problem.

However the first thing I would do is measure your voltage at the battery. Sounds like either the battery is toast and or the generator/regulator is over charging, which is very bad for the CDI. Most FLAPs can test the charging system and battery.

Once that is sorted check the operation of the ignition with a timing light.

[David Inc.]

That vacuum hose with a screw in it is almost certainly for the deceleration valve. It lets a bit of air into the intake after you lift off the throttle to hold the rpms higher. It's an emissions piece that breaks all the time, so the vacuum lines to them frequently end up removed and plugged. I wouldn't worry about that piece, but confirm that the vacuum port on the decel valve is open, it's right above cylinder 6.

[Flat6pac]

Sounds like you need a rebuild on the alternator, or at least the voltage regulator on the alternator. Either way the alt has to be pulled. You should get a new battery.
There is a relay under the passanger seat. Replace. Defective, it acts like a defective WUR controlling fuel pressure.
Bruce

[T77911S]

yes as said, get the battery issues straight first off.
clean the battery connections. clean the grounds and don't forget the one form the body to the tranny.
put a good battery in it then go have the system tested. a lot of parts store do it for free. don't guess on whats wrong
the relay under the seat as said.
check fuse 18 to see if it good. spin it to clean the contacts.

[premdes]

Wow. Thank you all. Much appreciated. Yes battery is red ultima with 3rd replacement. I keep taking back to autozone for new one. They test it and say it's fine. I tell them maybe but won't start the car. And i jump the car in the parking lot with power pack. So batteries keep getting replaced. I will test the alternator , and replace relay under the seat right off the bat. And I'm sure I have lubed and cleaned all fuse contacts and put new fuses in all slots.
I have had a bad rain where water filled the floor with several inches. Not sure If that did any damage to the "under seat" components? Last summer tore apart interior, cleaned, coated and inspected everything. Visually looked clean and no corrosion. Perhaps there is a multimeter I could apply here and confirm!?
The timing light is crucial but I will have to get a mechanic as I'm not sure what to look for in the light. Watched many YouTube videos but still not clear enough. I'll post on battery early next week as soon as I do the recommendations you guys posted. Great start!

[Bob Kontak]

Originally Posted by premdes

The timing light is crucial

Timing light is not your issue.

Drive to Harbor Freight Tools and buy the red cased multimeter which is always on sale for $25. Select DC voltage at 20V and check your battery voltage when car is running.

It should be about 13.8 volts. Report what you find.

If your OXY fuse / Lambda system is not energized it will result in horrible running with backfires. Not big ones, but consistent small ones and the car will have little power and poor throttle response.

Check if your underhood light is on when you lift it. That is on the OXY fuse circuit. Glove box light as well.

[T77911S]

let autozone test the charging system
clean your connections
check fuse 18

[boyt911sc]

Originally Posted by David Inc.

That vacuum hose with a screw in it is almost certainly for the deceleration valve. It lets a bit of air into the intake after you lift off the throttle to hold the rpms higher. It's an emissions piece that breaks all the time, so the vacuum lines to them frequently end up removed and plugged. I wouldn't worry about that piece, but confirm that the vacuum port on the decel valve is open, it's right above cylinder 6.

David,

The vacuum port to the decel valve is normally closed. A good working decel valve should have a vacuum reading below 12” Hg to keep it sealed. Once the vacuum goes up higher (15”Hg or more), the valve pops up and releases the pressure back to the throttle body.

This is why you will see some decel valves that have been disconnected or disabled being plugged because it was leaking. Some were left open and no problem because the valve is not leaking. The decel valve is not for emission because the decel valves are used in ROW cars with no catalytic converter.

Tony

[premdes]

Originally Posted by Flat6pac

Sounds like you need a rebuild on the alternator, or at least the voltage regulator on the alternator. Either way the alt has to be pulled. You should get a new battery.
There is a relay under the passanger seat. Replace. Defective, it acts like a defective WUR controlling fuel pressure.
Bruce

Thank you Bruce

I’m uploading the pics as I’m not sure what relay. I only see a 5 pin fuse but maybe they other units put in front of you may trigger some thoughts as well. I don’t even know what those things do down there lol. I did have a flood once and rain was 3 inches deep I opened the case of the jetronics and it looked clean and bright. No corrosion as I feared.

Thanks again.

Also as some have said. I do not have lights working in glove compartment nor trunk. But cabin light does work

Thank you
Amir

[AndrewCologne]

The small one in the middle

[SCadaddle]

The whole system isn't doing anything if the long connector with a cable isn't plugged into the Jetronic box.

[premdes]

Ok guys. We all maybe in our pajamas surfing the internet and PP forum these days. I just wanted to get back to everyone on their suggestions.

I checked all my fuses. And the lights ( no lights in cabin, trunk or glovebox). No idea what to even look for to fix those wires. I’m including pics of the wire in the trunk I pulled out to make visible for the pics. Hoping someone can shed a light.
I did pull the 5 pin fuse out while car was putting and idling rough, and no change in behavior. I purchased a new relay. And no change.

I’m in the mood to just drop the engine and gut it and start all over. May not do much if electrical but gives me a chance to rule out so many things including injectors, vacuum lines, etc etc. any thoughts?

[the-car-guy]

i had weird electrical / idling issues with my 82 sc as well ... i replaced trans ground strap and battery ground to chassis -- a lot of my issues cleared up --- i also up graded my alternator to the big one -- everything is available here on pelican

[High Life]

I have an 1981 SC with a CIS system and have had to work though a bunch of this stuff.

I would take the advice of any of the high count posters above - however my advice would be to work through one at a time and report back with measurements. (i.e. if you get 13.5 at the battery - your battery is charging) Next test - power to the lights? -if not move back to fuse? power to fuse 18? So on and so forth. This systematic thinking will help you discover the problem. I always start with a bunch of tests to help others help me. I would start with the voltage test first - since that is what most are pointing you towards. A muti-meter is your friend here and Bob can surely walk you through what to look for..

Next I would be ready to perform the fuel pressure test (order the gauges if you don't have any) get them coming cause it sounds to me like more than one issue.

Running a compression test and a leak down test give you good info - but I don't believe you are there yet - you would have other symptoms like smoke from the exhaust. I would not drop the engine without finding out exactly what is wrong. You cant start it and run the engine out of the car..(you technically can but it doesn't sound like your set up to do that)..

As you are looking for electrical gremlins - I found that my connector for the Lambda system was loose - AFR values all over the place.. Lamb DUH Connector??? I could change the idle by wiggling this connector. This is a different connector than the one under the seat..

I've also had a bad coil wire (the center spark plug type wire that runs to the center of the distributor) - not the green wire - that was arching once and causing a missfire.... but I digress..

What is the Voltage at the battery?

Do you have power at Fuse 18?

Is the xx pin connector cable installed to the Jetronic Box - pic shows it isnt.. ?

[Bob Kontak]

Originally Posted by premdes

I’m in the mood to just drop the engine and gut it and start all over.

Bite your tongue.

You figure out why or if the OXY system circuit is not energized with certainty.

You need juice to the relay on the Lambda box. Then the box sends a signal to the frequency valve on the back of the engine through the 12 pin connector.

You car will run like shiet without this working.

If you don't understand it ask questions on how to do it.

[Bob Kontak]

Originally Posted by High Life

A muti-meter is your friend here and Bob can surely walk you through what to look for..

Old men ain't got nuttin' else going on.

[High Life]

Originally Posted by Bob Kontak

Old men ain't got nuttin' else going on.

Tell me about it..

Because of all this virus stuff - Im sitting at home all day..

[boyt911sc]

Amir,

If I were to do the troubleshooting for your car, this is what I will do:
1). Check the fuel pressures (system, control, and residual). The residual pressure is not critical at this point.
2). Ignition. Connect an inductive timing light to determined the presence of ignition sparks when you crank the starter.
3). Test the integrity of your vacuum. If you have good fuel pressures, strong ignition signal, and the right amount of air, your engine should start and run even for a few seconds. If you are not getting any sign of internal combustion, you might have a significant air leak in the system. How much? We don’t know until you test it.

A set of pressure gauge kit is a mandatory tool for diagnostic testing of any fuel injection system. If you don’t have one, you are simply doing a guess-work troubleshooting. Keep us posted.

Tony

[Bob Kontak]

Originally Posted by High Life

Tell me about it..

Because of all this virus stuff - Im sitting at home all day..

I have a little semi retirement shop. I've got a 1965 International D1300 truck in there I am supposed to paint.

I get nothing but chicken shiet problems all day long from customers. I can't get to the truck. Need to strip it with a DA sander. About 1/3 done.

I am thinking to just tell the callers "I have a fever" Might muster some space.