Easy fixes you’d think would be difficult …

[Jack Olsen]

…and difficult fixes you’d think would be easy.

That’s the headline for my past couple of weeks.

My 50-year-old 911 hasn’t had a mechanical issue in a decade, but driving back from the track a month ago, I suddenly had two problems.

Problem 1: Very difficult to get just about any gear.

This one was scary, because I’ve got a soft, magnesium-case 915 mated to a later, 3.6 engine. And I’ve had them together for 20 years and over a hundred track events. And nothing has blown apart yet. Key word in the back of my mind, always: yet. At least, those were my thoughts on the drive home as I struggled to get it into first after each stop. It felt like a rebuild might be in my future.

Problem 2: 15-to-16+ volts coming from the alternator.

Why stop at one problem, right? If I didn't have a voltmeter in the car, I might not have seen this. It wasn’t overcharging long enough to blow up my battery, but the first symptom I noticed was trouble with my lap timer, which went black right before I saw the crazy-high voltage the alternator was putting out on my drive home. I switched on the lights, then the brights, fighting to bring the number back down. Visions of shims and gear-pullers to separate the fan from the shaft and all the nonsense and expense of a new alternator danced through my head.

I got home, and let the car just sit for a week. It was frustrating to have two totally unrelated problems, requiring work on different parts of the car. But it ‘was what it was.’ Finally, I took out the passenger seat and looked at my Wevo shift coupler (fine) and then checked the Wevo shifter, and finally pulled it out. It was also fine, but removing it revealed a problem. My ancient shift rod bushing had broken into two pieces and popped completely out of its fitting. There was no bushing at all holding onto the shift rod.

Could it be that simple? I ordered a new bushing for the shift rod and also a new one for the base of the shifter. Just avoiding having to re-adjust the shifter or the coupler would be a treat. And then, just like that, the new bushings went in, everything went back together, and in a shockingly short amount of time, I was rolling through the gears. Success!

Next up, the charging system. I decided to try just replacing the $50 voltage regulator on the alternator, and found a way to get access to the back end of the thing without removing the pulley or the fan or much of anything else. I took off the access port at the top of the shroud, undid the fastening belt around the fan housing, and the whole assembly slumped forward and it was a breeze to get into the back of the alternator and slide the new regulator in. It took even less time than the shift bushings. The car started right up. A steady 13.6-13.7 volts from the alternator.

I felt like a god. Or at least a very capable 911 owner.

Then it all came crashing down. My lap timer (a Solo 2) only charges when the keyed power is on, and I messed around trying to get enough charge into it to revive it. Stupidly, this led to my accidentally leaving the key in the on position – and then forgetting about it when I left the garage. It stayed that way overnight. The next morning, I found what I’d done. Thankfully, the car was on a trickle charger, so the battery wasn’t dead.

But I suddenly had a no-start problem.

This time, nothing was quick or easy. I first noticed that the humming sound I had always heard when the key turned was gone. That led to me uncovering the fuel pump (which is not a small trick when you have an aero cover on the underside of the car). That showed confusing results, where the pump would work with 12v applied form a separate source, but wouldn’t work with power from the DME. I swapped DMEs and still had nothing. It turned out I also had no spark. I finally found that a 12v lead to my 14-pin connector had corroded and broken off. I soldered it back.

So, problem solved, right?

No. I now had fuel and spark, and the car started -- but the idle was suddenly terrible and super-rich. There was no humming sound -- which I now knew wasn’t from the fuel pump. I swapped in another DME. No change. Reaching out for advice from Tyson Schmidt led to my swapping in a new Ignition Control Unit. No change. That moved me onto the Idle Control Valve, which now seemed the likeliest suspect. I learned it’s definitely the source of the reassuring humming sound. But they’re NLA or $815 from Porsche. I ended up sourcing an aftermarket one from Germany for $50. But that meant a 5-day wait.

During the wait, I noticed that when I disconnected the MAF sensor while the car was running, the idle would improve. I figured the ECU was switching to limp-home mode when it stopped getting a signal from the MAF. That couldmean the MAF sensor was bad. Or it could be the Oxygen sensor. Or something else.

I jury-rigged an Autozone 4-wire oxygen sensor as a swap, but there was no change. I cleaned the MAF sensor with the $14 can of cleaner. No change. MAF sensors themselves are not cheap ($260) and not returnable, so I didn’t want to jump to the conclusion that mine was bad. But then I found a $50 knock off (Chinese, no doubt) one on Amazon that I could get the next day. I ordered it…

…and it arrived tonight. I swapped it in, and that was the trick. The new one immediately fixed the idle problem.

I’ve now got some new spare DME relays, a spare ignitor, a spare Idle Control Valve… and a running car. I’m out maybe $200 for the mistake of leaving the key on. But that $200 stings because it's 100% owner-caused. My theory is that the already-old heating element in the MAF sensor burned itself out during 12 hours of power with no engine-idle airflow moving over it to cool it.

Or it was just old and failed. But I think it was the 12 hours of power and no airflow.

The lap timer was revived with a $10 battery designed for a baby monitor. But its charge circuit still isn’t working, so it’s going to have to go back to AIM to get fixed. I messed that repair up enough to revoke my god status for a while. I’ll hand that off to a technician.

The good news is that I’ve got another track day on Wednesday, and the car is charging, shifting, and running again. $200 every 10 years, even when it's my own fault, is okay, I guess. I’ll get my lap times from the in-car video if I need them.

The big fixes were easy. The little one turned into a huge pain in the neck. Sometimes, that’s how it goes.

[emac911]

Glad you got it sorted. I know there are several places that rebuild MAF, may be worth sending it off for a spare.

One time I changed the spark plugs on a car and it wouldn't run. After a ton of troubleshooting I realized I had been leaning on the coil wire and broke the terminal. Live and learn.

[fanaudical]

Great post.

I can't tell you how many times I've gotten into something that I thought would be difficult to find it easy and vice-versa...

[lateapex911]

Classic.

yea, it is AMAZING how much a little mis alignment in the shifting rod/coupler/bushing can totally mess up the shifting action.
I too jump to many conclusions when it comes to things not working on my 911, and I ALWAYS figure it's the worst one LOL. (And I always blame myself too...)

[Otter74]

Glad to hear, even the results with the MAF (which wasn't that bad.)

Years ago, when I had had my car about a year, I was driving back to Chicago fron SW Michigan on a holiday weekend in miles and miles of heavy stop-and-go traffic when suddenly I lost access to 2nd and 4th. As if traffic like that isn't un-fun enough in a 911, I then had to wind it out in first to get to 3rd every time I moved more than 20mph. That was a pain. Got home and found that my coupler bushing had disintegrated. Better yet, after I'd bought my car someone had sent me their misc. leftover 911 stuff after they sold theirs, which stuff included a new coupler bushing. So in about 30 minutes and for zero dollars, I had a normally-shifting car again.

[GH85Carrera]

Originally Posted by lateapex911

Classic.

yea, it is AMAZING how much a little mis alignment in the shifting rod/coupler/bushing can totally mess up the shifting action.
I too jump to many conclusions when it comes to things not working on my 911, and I ALWAYS figure it's the worst one LOL. (And I always blame myself too...)

The shifter bushing on my 85 failed when I was in a city 100 miles from home. It was a tricky thing to get any gears, but 5th and reverse was just unavailable. I had to drive home on the interstate in 4th gear but that was no major issue.

Just replace that bushing and all was good. I have the center console on my car, with the AC controls, central locking and the speaker control in there so removing the console is a real pain in the butt and then the shifter work is easy.

[Jack Olsen]

Yes. My fear was disassembling and/or readjusting the shifter. That was scary, only because I'd never done it before. But once you get in there, those bushings are a piece of cake.





TWIST AT THE END OF THE STORY!

This morning, I buttoned everything back down, re-installed the seats and got all the carpet and such back in place. I've got to fill it up for its drive to Willow Springs tomorrow morning, so I backed it out of the driveway...

...and immediately saw that the lap timer is now re-charging its battery, with no issue at all.

So... as it turned out... (maybe...) all I'd needed to do was let the lap timer sit until its charging function re-set, or until the whole Solo2 essentially did a hard restart. Or something. But the fiddling around that led to my mistakenly leaving the power on, and all of that troubleshooting, and all of those spares I sourced, all in order to discover I'd burned out the MAF sensor. All of that was even more unnecessary than it had seemed, previously.

Live and learn.

[FA-18C]

Jack, for most of us, you just described a typical month with the old beasts.

Full restoration in progress, 2-3 nuts and bolts at a time. 32,578 parts to go.

[911 Rod]

When people talk to me about buying an old air cooled I quickly them that it is a "hobby car".
This means it will be your hobby to fix it.

[ahh911]

That's what I've come to realize. The first two years was different though, just couldn't wait to get the miles in. Headstud when new, engine out, mild stress, 20 k miles since and now I can relax and enjoy the hobby, changing shift bushings, window seals, pedal coverings, etc... I find replacing the rubbers especially enjoyable, is it just me? Also, all Genuine parts when possible is my latest, just not worth the savings, in most cases that is.

To keep with the theme, getting the existing york a/c system running in my 81sc. Oil extractor vacuum pump, couple bottles of r12A, some correct oil for the compressor, gauge, then lots of internet hunting. When it came down to doing it, 20 minutes and the whole summer of very very cool air. I had debated changing the drier, then thought twice about introducing more headaches if I accidently destroyed a coupling etc... So something that I'd never done before was solved without over complicating the issues. Mind you, the prior winter I'd taken out both blowers in front and cleaned them out and re-installed, without incident.

Phil

[sugarwood]

Wiper blades. Either takes 30 seconds or 3 hours.
Also, NOCO jumper starter clamps that don't fit.

Good reminder to noobs like me that that if ALL gears are hard to get into, it's probably a shifter issue vs. a gear issue.

Can you post a link to the $50 MAF ?
Part number?

[FA-18C]

Rod - I do something similar. When they are oohing and ahhing over the Porsh...I remind them it is 34 years old, makes some funny noises now and then, provides anti-mosquito fogging at start (most of the time), and randomly has things that worked last drive, but not this one...Yes, a never-ending project. Love classic cars.

[Jack Olsen]

Originally Posted by sugarwood

Can you post a link to the $50 MAF ?
Part number?

https://www.amazon.com/gp/product/B09P55YZKT/

[smadsen]

I've heard you can make a small fortune driving & repairing a 50 y/o Porsche.

[911 Rod]

Originally Posted by smadsen

I've heard you can make a small fortune driving & repairing a 50 y/o Porsche.

When you spend a large fortune on the car and repairs .....