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BoxheadTim
BoxheadTim MegaDork
8/12/19 8:19 p.m.

Why "the slow learner"? Well, that'll be me. This is the third 911 I've owned, second Carrera 3.2, and all of them have had a habit of producing big bills. I no longer wonder why Pelican, well, has a pelican as their mascot...

Anyway, this is the car that this is all about:

It's a 1989 Carrera 3.2 Cabriolet - last year of the torsion bar suspension, so depending on which purist or rivet counter you ask, it's one of the more desirable 911s. It's also a less desirable one because, well, it's a soft top.

The story how I got this is a bit sad. The PO wasn't a huge car guy, but he always wanted a 911, so for one of the big round birthdays, him and his wife bought this car from a dealer in my old stomping ground of Reno, NV. He loved the car and had it for quite a while (at least 12 years, if not longer) until he passed away sometime last year. One of the stories I heard was that was pretty much a stoic and the only reason the family noticed that his condition was serious was because we barely drove the car anymore.

His widow happened to be a friend of a friend and said friend asked me if I could check the car out as she wasn't a car person either, didn't know much about 911s and the only people interested in buying the car where wannabes who fancied themselves wheeler dealers, apparently without the cheeky chappy charm.

Long story short, the consultation about what she had turned into "I think you're the best person to have it" followed by a number that I couldn't say no to, but with the implicit unspoken agreement that this car was not to be flipped. So here I am, finding myself with another 911-shaped moneypit instead of an R32 GT-R that I had been lusting for.

Right, so what do we have here?

The car had been modified, either by the supplying dealer or whoever sold the car to the dealer. I knew about the reputation of the dealer (let's just say you can consider it "variable") - there is correspondence with the paperwork that basically threatened to make life for the dealer legally rather uncomfortable for selling a car to a customer in CA with essentially all smog equipment removed and somehow still getting it smogged.

Which brings me to the mods and general state of the car - it obviously has the wrong wheels on it (Cup 1s instead of Fuchs), a MAF conversion from a company called Autothority who probably aren't around anymore, SSI stainless headers and what I consider an obnoxiously loud dual exit "muffler" that's a pre-74 pattern. It also sports a typical dead Southwestern interior (driver's seat ripped, the rest of the seats could be covered in parchment instead of leather), a not very great paintjob in the original colour and a couple of running problems.

On the plus side, it's a Southwestern car with little to no rust in the body. While mechanicals on these things are (sometimes stupidly) expensive, they're generally not as expensive as fixing the bodywork right. And I didn't want to deal with rust. Also, almost everything is present and accounted for.

I did notice that when I drove the car back in January, it had some sort of stutter/hesitation around 2k rpm at small throttle openings. That's not unusual for one of these and given the overall condition of the car I figured I'd start with a tuneup.

Well, seven months later I actually got around to said tuneup. Try to tell the difference between the new and the old spark plugs:

In case it wasn't obvious, the used plugs are the ones with the crazy (1mm+) gap.

The cap and rotor didn't look much better, so I replaced the whole shebang. I also bought some new spark plug wires (aftermarket) from a Porsche specialist, but they were not a good fit so I didn't put them on. Also changed the fuel filter while I was wedged in there.

Of course the sound deadening pad is falling down and covering about a third of the air filter, too:

Once I got it back together it fired up quickly, but it also attempted to smoke out all moskitos in the nearest three counties:

This was taken after the smoke started to clear...

Anyway, time for a test drive.

BoxheadTim
BoxheadTim MegaDork
8/12/19 8:37 p.m.

First test drive came to an abrupt almost-end a few hundred yards down the road as the dizzy cap with it's interesting hook system had come a tad loose. I managed to limp the car back home, put the cap on properly again and went back out for test drive number two.

It still "popped" into the exhaust a bit on idle, and the stutter/hesitation was still there, too, but less pronounced. Not quite declaring victory I decided to take it onto a longer test drive.

While much fun was had, I noticed that it was running worse as the engine got up to temperature. The rpm range of the stutter increased, up to the point where it would suffer from occasional hesitation under load at 4k+ rpm and the odd backfire through the exhaust when I blipped the throttle on downshifts. It also felt a bit down on power overall.

Got it back home, rearranged the garage so I could put the 911 in my shop rather than the "house garage" and now I get to try and figure out what the heck is wrong with the way it runs. The Pelican forums show that it's not an uncommon problem, but the trick is to find out what is causing it. Keep in mind that the ECU has no diagnostic port, so swapping parts is the usual way of diagnosis. Which isn't really an option thanks to the MAF conversion that needs a special ECU chip. Grrr.

The issue does feel like it's an electrical issue, especially as it gets worse then more components heat up. But of course we're talking thirty year old electronics that have been modified, plus a couple of mystery boxes added for extra charm.

Anyway, the plan for diagnosis is as follows:

  • Test the coil. The car has been berkeleyed about with, there is a chance it's not the original coil and even if it is, they're getting long in tooth and have started to fail. Oh, and the kicker is that there are several types of 911 coils that look very similar but aren't. Yay. Of course, the replacements you can get aren't much good and seem to fail regularly, too.
  • Stick the replacement plug wires on, just in case the original wires are going bad.
  • Pull the ECU (aka DME), pop the lid and check that it's got an appropriate chip in it and that it sits well in its socket. Also check if the ECU has water damage - they're under the driver's seat, after all. While in there, swap out the DME relay as they're also a notorious failure point.
  • Clean the MAF. All that I need for that is the cleaner (which I have) and some time (well...)
  • Test the sensors - the O2 sensor (which only works on one cylinder bank, thanks to the SSIs) and the CHT sensor are both known to fail and cause these symptoms.
  • Try to determine if the intake gaskets are OK. They're another notorious C3.2 failure point. I have a set of replacements but they're a PITA to fit - even the pros take at least 1/2 day to change them thanks to the grandiose access under the hood.
  • Probably pull the injectors and have them cleaned and tested. They're also pretty notorious for clogging up
  • I hope the dang thing is running at this point because otherwise I'm having a real problem. I am somewhat toying with MS+ITBs in my really bad dreams, because learning to map an engine is best done on something that's going to run at $15k-ish for a decent used one, right?

Once it's actually running properly again, the plan is to address some of the other issues (rear suspension spring plate bushes, getting the driver's seat redone, general cleanup) and actually drive it for a little while. Well, after putting the proper Fuchs on, which I already heave.

Based on the outcome and the size and depth of the crater in my wallet needed to get to this point, I'll likely have to get it repainted and address some of the other cosmetics, and then hopefully drive it some more. It's a great car for the roads around here when it runs right.

irish44j
irish44j MegaDork
8/12/19 8:50 p.m.
BoxheadTim said:

  I no longer wonder why Pelican, well, has a pelican as their mascot...

 

It took me a minute to get this.

for a second I thought you were thinking of an Albatross, as in " these old cars are like an albatross around one's neck" lol

 

GarageGorilla
GarageGorilla New Reader
8/12/19 9:14 p.m.

I don’t know a thing about Porsche’s, but for your symptoms, I would check the fuel system: especially injectors and fuel pump.

HundredDollarCar
HundredDollarCar New Reader
8/12/19 9:35 p.m.

Following along.  Hoping to pick up any relevant tidbits applicable to a decade older example.

Woody
Woody MegaDork
8/12/19 9:36 p.m.

Start with all the cheap and easy stuff. Clean all the grounds, electrical connections, fuses and relays.

yupididit
yupididit UltraDork
8/12/19 10:04 p.m.

Courage shall be rewarded

BoxheadTim
BoxheadTim MegaDork
8/13/19 7:13 a.m.
irish44j said:
BoxheadTim said:

  I no longer wonder why Pelican, well, has a pelican as their mascot...

 

It took me a minute to get this.

for a second I thought you were thinking of an Albatross, as in " these old cars are like an albatross around one's neck" lol

Heh, I only got the pelican joke when a friend explained it to me .

One could argue that both birds would make an appropriate mascot when it comes to "cheap" Porsches.

BoxheadTim
BoxheadTim MegaDork
8/13/19 7:17 a.m.

In reply to Woody :

Will do. Fortunately most of the stuff listed above is relatively cheap other than having to buy a few tools for measuring fuel pressure as I either have the parts already or they're not that expensive to acquire. I am still hopeful that it's the standard Carrera 3.2 issues.

Dusterbd13-michael
Dusterbd13-michael MegaDork
8/13/19 7:18 a.m.

Can you explain the joke? Ive always wondered....

BoxheadTim
BoxheadTim MegaDork
8/13/19 7:27 a.m.

In reply to Dusterbd13-michael :

One of the defining features of pelicans is that they have big bills.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
8/13/19 7:35 a.m.
Woody said:

Start with all the cheap and easy stuff. Clean all the grounds, electrical connections, fuses and relays.

Quoting this because it deserves quoting. Clean electricity seems to be very important to these. 

Dusterbd13-michael
Dusterbd13-michael MegaDork
8/13/19 7:52 a.m.
BoxheadTim said:

In reply to Dusterbd13-michael :

One of the defining features of pelicans is that they have big bills.

Oooohhhhhh!!!!!

 

Now i get it! 

Thanks. Im kinda slow sometimes. ....

docwyte
docwyte UltraDork
8/13/19 8:31 a.m.

Remove the Autoauthority MAF and go back to stock.  They used to sell a bunch of MAF conversions for the 944 Turbo's, which did work, but the tuning was very coarse and power gains/reliability weren't really improved over stock.

Dirty MAF generally won't cause what you're describing...

BoxheadTim
BoxheadTim MegaDork
8/13/19 8:40 a.m.

In reply to docwyte :

Yeah, the MAF cleaning was more a case of "while I'm in there".

The one little snag with going back to stock is that I don't have any of the stock parts, and the AFM isn't that easy to find in known good condition. Plus of course they had to futz about with the wiring to install the MAF conversion, so reversing the conversion might introduce other variables that I'd like to control for.

All that said I'm not a big fan of this conversion and also the fact that it pulls in nicely heated up air due to the location of the filter. I'm probably going to keep an eye out for the stock parts anyway.

NOT A TA
NOT A TA Dork
8/13/19 9:03 a.m.

Following along for incentive to get my 86 Cab back on the road. Ran fine when parked on the rear lanai almost exactly 10 years ago. Then life happened and it hasn't moved since. Looks similar to yours with the red/black & black leather. ROW Faux 941 3.2 with a 915 box.

[URL=http://s240.photobucket.com/user/NOTATA/media/86%20Porsche%20Widebody/86PorscheWidebodyConv129.jpg.html][/URL]

Woody
Woody MegaDork
8/13/19 10:16 a.m.

In reply to NOT A TA :

I've only recently learned what a lanai is. Isn't there supposed to be a pool in there though?

java230
java230 UltraDork
8/13/19 11:01 a.m.

Oh this should be fun. Following along.

docwyte
docwyte UltraDork
8/13/19 11:10 a.m.

In reply to BoxheadTim :

Definitely inspect that wiring job they did for the MAF conversion, make sure all the wires are properly joined...

octavious
octavious Dork
8/13/19 12:11 p.m.

 

If you do decide to take the intake off and replace those gaskets, dropping the motor to do it makes it pretty simple.  Granted my motor is out and ont he stand already, but this only took me about 20-25 mins, the other afternoon.  I did presoak all those 8mm barrel nuts.  My car is a 76, but the motor is a 85.  

 

ValourUnbound
ValourUnbound New Reader
8/13/19 12:15 p.m.

This is the thread I have been looking for. I was surprised when I couldn't find a live aircooled thread for the past few months.

BoxheadTim
BoxheadTim MegaDork
8/13/19 1:36 p.m.
docwyte said:

In reply to BoxheadTim :

Definitely inspect that wiring job they did for the MAF conversion, make sure all the wires are properly joined...

Definitely will. I tend to get goose bumps - and not of the good kind - when I see wires slathered in electrical tape.

I also found the installation instruction for the MAF conversion in a thread over at Pelican, and they mention that there is a potentiometer that's supposed to be used to set the CO2 at idle (by manipulating pulse width of the injectors at idle.

I'm currently hoping that it's buried somewhere under the tape and wondering how I translate the value given (which is obviously for a car with a cat) to what I have on the car. Yay frown.

BoxheadTim
BoxheadTim MegaDork
8/13/19 1:37 p.m.

In reply to NOT A TA :

That looks tasty.

BoxheadTim
BoxheadTim MegaDork
8/13/19 1:39 p.m.
octavious said:

 

If you do decide to take the intake off and replace those gaskets, dropping the motor to do it makes it pretty simple.  Granted my motor is out and ont he stand already, but this only took me about 20-25 mins, the other afternoon.  I did presoak all those 8mm barrel nuts.  My car is a 76, but the motor is a 85.  

 

I'm seriously thinking about pulling the motor or motor+transmission if I have to get at the intake gaskets. I have to redo the sound deadening pad anyway, and that is much easier with the motor on a stand.

OTOH I'm not sure if my QuickJack gives me enough clearance to drop the motor. I think there's a way to find out, though.

dps214
dps214 Reader
8/13/19 1:50 p.m.

Quick jack probably won't get it high enough. But once the engine is unbolted the rear of the car is pretty light and it's not very hard to jack it up high enough to slide the engine out if you have a high lift jack and some decent stands. Front end of the car doesn't even need to leave the ground.

I know it's not cheap but honestly I'd just replace the maf system with either the stock parts or a better maf kit now. The autothority stuff barely worked when it was new, there's almost no way you're going to get it to work correctly now 20+ years later. You're just going to drive yourself crazy trying to troubleshoot outdated junk that's going to need to be replaced eventually anyway.

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