924Board.org

[Olivettibakebean]

Sup guy & girls, 1st post so be gentle. I'm very much a backyard mechanic with a few builds under my belt. Last week I spotted an 1980 931 in need of help. The price is right I just need to clear out my garage and find a way of getting it from Sacramento to San Fran cheap.

The car in question has 59k and has been sat in storage for almost 20years. It has a blown head gasket between two cylinders, no cross contamination of fluids and compression checks out everywhere else. The clutch master/slave need rebuilt but has a new trans and clutch. The only thing that bothers me is the car is fouling plugs. Owner thinks its sticky fuel distributer, I plan to rebuild it but I have read it could be the engine exhaust valve guides. Can I replace these with the engine in the car? How many does the 931 have? are 1980 924 turbo one's the same as later 924's or 944?

I plan on stripping it back but want to avoid removing the engine if possible. I see with the right method you can replace HG with the engine still in.

Here's a short list of service I intend to do.

Oil
Battery
Oil Filter
Brakes Re-build
Thermostat
Air Filter
Fuel Pump
Clutch Slave Repair
Water Pump/gasket
lambda O2 Sensor
Repair kit for Bosch Fuel Distributor
Timing Belt & roller
Fuel Filter
Alt belt
Spark plugs
Distributor rotor
Starter Carbon Bushes
Brake Pads
Brake Fluid
Coolant
Head Gasket
Radiator switch
New stretch head bolts
Oil pressure sensor
Transmission fluid
Engine exhaust valve guides

Any suggestions on jobs I should do while I have the head off would be appreciated.

One last thing, I have heard a few horror stories since researching this car regarding the early turbo models. On the other hand I have heard they are the best of the bunch if treated right. Opinions?

[Grenadiers]

Welcome to the Org board! First of all, don't try starting the car till you complete your service. The CIS distributor is most likely varnished from old gas. Your System and Control pressures are out of whack, leading to your plug problem. The belt itself is old, and if it breaks, say goodbye to a few valves. Removing the engine is better for the head work, and other inspections/repairs you want to do. Get a Haynes manual for the car, and do plenty of research on this board. Good luck.
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'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

[ideola]

Highly recommend having the fuel distributor professionally rebuilt. I've had good success with Jaytan Industries there in California. You can also look up SpecialT Auto, which specializes in DeLorean stuff, but also has tremendous experience with all of the variants of CIS, including those components on our cars. You might also need to have the WUR rebuilt. If you can get ahold of a proper CIS test kit, you might be able to do some diagnosis ahead of time, but with a car that's had those issues and sitting that long, my suggestion would be to just get rebuilt components.

As for the head work, it is definitely very doable to pull the head with the engine in situ, as follows:

• remove two nuts on the top side of the three-bolt flange, exhaust mani to turbine housing
  
• remove one nut on the underside of the three-bolt flange (need extensions and wobble socket)
  
• remove j-pipe: four nuts at the wastegate, and two nuts at the exhaust mani
  
• remove fuel lines and entire AFM/Fuel Dizzy assembly. You will need to disconnect and gently fish out the two lines to the WUR and the one to the frequency valve
  
• remove timing belt
  
• disconnect and move out of the way all of the engine harness connections in the vicinity of the head (CSV, AAV, WUR, TTS, CLT, TPS, IAT, and FV)
  
• disconnect and remove the coil
  
• remove the entire intake manifold assembly
  
• remove valve cover, and remove head bolts
  
• disconnect coolant hoses at front of motor and rear of head

There may be a few other details I've forgotten, but at this point, the head should lift right off.

Now having said that, it is almost certain that the turbo will need to be rebuilt, and for that, it is much better to just pull the whole motor. This will give you opportunity to inspect and refresh the clutch, as well as the RMS. Heck, at that point, you might consider a complete refresh of the long block. Several of us here have had excellent success with Majestic Turbo in Texas. John Walzel knows these turbos and will take care of you, although he can be a bit slow sometimes.

The fouling plugs could be due to anything. Bad valve stem seals, improper fuel mixture setting, malfunctioning WUR or fuel dizzy, and a whole host of other issues. So I wouldn't worry about that too much at this point.

RE: the head reconditioning, the main things to look for:

• Evidence of valve-piston contact. If this has happened, there is a high likelihood of a bent rod, bent valve, loosened valve guides, and other problems. Ask me how I know.
  
• Damage to the block deck and head surface due to the blowout of the head gasket
  
• Bent valves, which can also lead to damaged valve seats
  
• Inspect the lifter bores for damage

The 931 valves are different than the NA valves, so you will need to source either new replacements or a used set (I have several on hand, although none listed in my online used parts bin at the moment). I strongly recommend having a qualified, experienced machinist measure the tolerances on the valve guides.

RE: the 931 as a platform, definitely the best of the narrow body cars in my opinion, and I personally much prefer the performance characteristics of the S1 (1979-80) turbocharger to the S2 (1981-82). Also, the S1 has the simpler (albeit less sophisticated) ignition system, so it is much easier to keep these cars running than the fluky DITC setup in the S2 cars. Adding a water-meth injection kit and an in-cockpit manual boost controller will allow you to safely increase boost to ~12-15 psi (depending on a lot of variables), which completely transforms the cars.

I would be grateful to provide quotations for everything on your list above. I specialize in the 924/931, and can get everything on that list and more. Feel free to reach out to me via PM or email (dan DOT beckett AT ideola DOT com) with any questions as you go through your restoration.
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erstwhile owner of just about every 924 variant ever made

[Olivettibakebean]

Thanks guys, glad to hear the s1 isn't a lost cause. I understand from past experience project don't always go to plan but I'd like to run the car while upgrade the brakes, diff, shoxs and cooling before pulling the engine and rebuild/revamp.

If I buy the car I'll grab myself a haynes manual, I found some pdf of service manuals in the time being to flick through.

Ideola I'd really be interested how much you could get me the following for:

Oil Filter
All four brakes re-build
Thermostat
Fuel Pump (upgrade if poss)
Clutch Slave Repair
Water Pump/gasket
lambda O2 Sensor
Repair kit for Bosch Fuel Distributor
Timing Belt & roller
Fuel Filter
Alt belt
Spark plugs
Distributor rotor
Head Gasket (Thinking about a copper or steal 3 layer one but I've heard horror stories)
Radiator switch
New stretch head bolts
Oil pressure sensor
Engine exhaust valve guides

Is the fuel distributor a real pain to rebuild if so new ones aren't too expensive, perhaps I'm looking at cheap crap though. I have a past with VW parts so I know to avoid brazilian and chinese bits from experience but I'm new to Porsche but my family have always driven them.

[ideola]

I'm leaving for Stockholm today, but I will try to get a quote out to you today (tomorrow at the latest).
_________________
erstwhile owner of just about every 924 variant ever made

[Olivettibakebean]

[Olivettibakebean]

[racetherat]

[Olivettibakebean]

[Ponz]

I have owned my 79 931 Euro for 13 years and the only item that broke was the drivers side motor mount. Regular oil changes, spark plugs, check tires add gas and go. I am now due for a new Suppertrapp tailpipe. It rusted after 12 years.
_________________
77 1/2 track car
79 931 Euro
87 911 Targa

[Olivettibakebean]

[Paul]

It is very easy to spend $10,000 fixing a S1 931, BTDT.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.