73 911t 8 years sitting...

[tharbert]

I have a 72 911t, 2.4 w/botsch fuel injection I bought a few weeks ago. I have been pouring over forums and threads trying to get information on what I need to do to start the engine after sitting for 8 years. The PO who bought it in the mid 70's said it ran great when he parked it in 2000. It had developed an oil tank leak. He had a replacement tank but never tackled the repair. He had intentions of restoring the car but after having it for so long, I think he just lost interest in spending more money on it. "She who must be obeyed" asked him for the garage space and I was there to pick it up the next day. Anyhow...

I did a thread search here and couldn't find any discussion about this but I'm sure there has to be something. If this had been covered, please post a link to the thread.

In any event, this is what I have done and what I have planned. I am thinking top down so I started with the fuel.

Fuel
-Replaced fuel filter ($75 - yikes!)
-Removed and drained fuel tank
--Removed external corrosion, primed and undercoated
--Inspected tank internally, seemed very clean
-Disconnected and blew out fuel lines
-More on injection system below...

Air
-Replaced air filter
-Checked for bugs and mice

Oil:
-Removed/repaired/reinstalled oil tank
-Replaced oil filter

Spark:
-Removed/cleaned, regapped plugs (will replace after start-up)
--Plugs are still out
-Made sure no spiders had invaded the distributor

-Inspected heat exchanger and engine compartment nooks and crannies for flamable debris from rodents/bugs (found 2 mice nests in trunk)

As for the mechanical fuel injection, I have two trains of thought.

1) It can't contain very much old gas. Disconnect coil wire. With the plugs out, squirt a tablespoon of motor oil in each piston. Use the starter to crank the engine for 20 seconds, several times . This should move the new oil throughout the engine and purge the pump and injectors of any old gas. Refuel with gas w/injector cleaner additive.

or

2) Refuel with gas w/injector cleaner additive. Back out all the injectors. Put a baggy over each injector. Disconnect coil wire. Oil the pistons... Crank engine to purge fuel into baggies. Observe injectors are spritzing properly. Reinstall injectors

Then, reconnect coil, test for spark at the plugs. Reinstall plugs.

Start her up. So, if the PO is correct and the engine was indeed OK when it was parked then I'm hoping that my approach will, at least, do no harm, and hopefully result in a puff of smoke from 6 tablespoons of oil and eventually the purr of a 2.4 at idle.

Is there something else I should do? Look for? Injectors approach 1 or 2?

This is my first pet project of this type and I'm hyped about it! Any input is appreciated!

[dtw]

What's MIS?

[tharbert]

Sorry, I meant mechanical fuel injection. Its not the K jetronics system. Have edited to get rid of MIS...

[dtw]

Ah ok, wasn't sure if you had CIS or MFI. Or the rare six-throttle CIS based on MFI known as CIS...very rare indeed...

Your procedures sound pretty good. I'd also overhaul the brake system, including replacement of master cylinder and flex hoses, and rebuild the calipers. Change tranny fluid too.

Did you peek under the fiberglass shroud to look for mouse nests? You can do this relatively easily by removing the fan housing along with the fan and alternator.

The biggest question mark is probably the MFI pump itself. There's a good chance that several of the pistons inside the pump are frozen up. You might want to pull the pump, and fill it up with Berryman's B12 Chemtool or Marvel Mystery Oil for a week or two, turning it every so often, to help free things up. That's also a good time to pull the injectors and spray pattern test them.

Welcome to the board. Got pics of your new ride?

[pozee]

Don't drive it unless you have a pro check your wheels for cracks and tires for rot.

Have fun!

[Hugh R]

Don't know much about your vintage, pull the plugs, and hand crank it over a few times with the fan nut until it spins freely. I guess you already know the engine isn't frozen, right?

[bkreigsr]

might be better to leave the coil wire connected and disable the spark by removing the rotor then replacing the cap.
-eliminates any risk of a spark jumping to all the gas/fumes that might appear during the start-up attempt.
Bill K

[tharbert]

Pulled the injectors and cleared the steel lines of old gas. The more I thought of it, the more I liked option 2.

I plan on bleeding the brakes, inspecking the calipers, and going over the rims/tires very carefully. It will get new tires once I'm a little further along with my restoration. A full brake job is on my to-do list.

No, the engine hasn't seized. I can turn the engine via the fan nut. I haven't moved it more than a couple degrees since I didn't want to fire the injectors.

I still have an oil tank issue... In my first post, it says removed/repaired/ reinstalled oil tank when in fact the tank is still at the machine shop for repairs. I have two and both have issues. Once I pick up and install tank, I'll be pretty close to putting the battery in and turning the key.

I am going to look closely at the idea of pulling the MFI pump. That may just be my next move. As clean as everything seems to be, I may try to fire it up first and reserve removing the pump unless there's a problem.

Pictures:
Nose
Tail
Right side
Left side
Oil Door - 72 only
Oil Tank holes
Speedo

There are rust issues but from what I've seen so far, it's not bad.

[dtw]

Just a caution - you could have 4 injectors firing perfectly, and 2 firing inconsistently or lean (seen this quite a bit on MFI motors) due to a couple of sticky pistons in the injection pump. Not only does this make the engine nigh on impossible to tune, it creates a dangerous lean condition in the affected cylinders. I'd strongly recommend checking out the pump and injectors before starting it up.

BTW your car is a '72 .

[LakeCleElum]

Sounds like you've taken a very educated, rational approach. I 2nd the suggestion of pulling the Alt. and looking for mice nests on top of cylinders. This is a place they like and it can really interfer with proper engine cooling.

After you get it running and B4 putting it on the road, 3 suggestions:
1) Replace your flexible rubber brake lines. They plug up from the inside and won't release pressure, causing brakes to drag.
2) After that, check that your caliper pistons are retracting. If not, rebuild calipers. Of course, during either operation, you will be changing brake fluid - very important.
3) Grab the top of the front shock insert and move from Side to side. I've had 2 older cars to put on the road. Both had the big nut that holds the insert in the strut come loose. When you hit a bump, you'll think your front end is falling out until you tighten down the nut!

Good luck..

[javadog]

You might consider pulling the valve covers and putting some oil on the cam lobes before turning it over. It takes a little while for oil pressure to build and oil to get to the cams.

Not sure I'd try to run the motor without removing the injection pump and sending it out to be inspected and cleaned.

JR

[RussR]

From what i've read of other T's i'd strongly recommend turning the engine over by hand. I think there is more than one thread on here about seized pistons from T's sitting too long

[tharbert]

I really do know it's a 72. Don't know why I keep saying 73. Must be the shock of suddenly becoming a Porsche owner...

[FenderBender]

Welcome, Make sure to clean the filter in the fuel tank. Run some marvel mystery oil in the gas. Berrymans B12 works good to for cleaning. Do not use a baggie, use a glass jar and be very careful. Read up on the CMA Threads.

[scottb]

I've read several threads over the years that discuss squirting Marvel Mystery Oil into cylinders on engines that haven't been run in awhile. IIRC, some people recommend doing it daily for several days, and then try to carefully crank the engine by hand.

YMMV.

Good luck, and post updates!

[tharbert]

OK, a couple updates. The PO bought an oil tank to fix a leak. That's where I bought the car (8 years later). In any event, the second tank had some holes at or above the filler cap line. I had my local MS braze up the holes. There were some identical brazes on the other side but they looked MUCH NICER! I can only describe what you see in the picture as "originally swiss cheezey."



Preparing the repaired unit for installation, I gave it a good coat of rustoleum. I also spot treated a few rust patches under the fender. I intend to tackle all that after I know the engine is sound.

So further prep of the fender for the tank turned up some (I think) original nylon bushings.



I gave the area under the bushings a coat of undercoating. Upon the second coat I used the wet undercoating to glue the bushings to the recesses. I found no bushings for the smaller "nubs" east or west of the larger north/south "nubs."



The PO's mechanic had used a thin coat of liquid gasket (orange) to hold the bushings in place.

I have, under advise of those here, soaked the MFI pistons in Mystry oil and turned the unit over every couple days. I was a bit reluctant to mess with removal of the MFI untill I read a procedure to soak the pistons without taking the unit off the motor.

I plan to start her up this weekend. More soonest...maybe video of my failure or success.

Tom

[tharbert]

I have to add here... I know the PO - emeritis professor. He has ALL receipts dating to about the mid 70's. Way cool! Notice no cab in glass. Good night.

[tharbert]

I was to the point of priming the fuel system a few nights ago. I had put the new battery in and finally sat in the driver’s seat and turned on the ignition. The first thing that struck me was that there was dead silence - no fuel pump hum.

Although the manual said it was under the rock guard, it was actually nestled next to the left rear wheel well. After checking it was getting 12v, I pulled the unit, flushed out the pump with mystery oil and bench tested it. It spun up right away so back in the car it went.

I got 2 gallons of 100 octane aviation fuel then topped it off with premium. I doped the 5 gallons with more mystery oil and some injector cleaner.

After a bit of cranking, it coughed a few times. On the next crank, it fired up. I can now officially call my car a driver rather than a roller.

The immediate issue was oil smoke. The oil smoke continued after I believed the pre-start tablespoon per cylinder should have passed. Indeed, I think I had one or more oil rings stuck. Talking to my neighbor who had a 69 911T, he suggested letting it get to operating temp. Sure enough, the rings reseated and the smoke went away.

The second issue at hand was cam chain noise. We popped the left cam cover; the location we determined was making the noise. I found the pieces below at the bottom of the cam chain area:



My neighbor, Bruce said it was a "quick fix" for hydraulic chain tensioners. He said he'd used a non-hydraulic fix that required adjustment every 5k miles.

I did notice that one small bolt and a small hunk of aluminum are missing from the broken "quick fix.". I'm hoping to find them in the sump screen. When I get a gasket, I'll go looking for them.

So now I'm off to the pelican forum search for ways to fix the tensioner (s.)

[tharbert]

I have a new set of carrera tensioners ready for installation tomorrow. After getting Wayne's book and catching up on the tensioner debate here, I've deceided to update the mechanical units. I'll probably rebuild the old tensioners and put them on the shelf along with the very lightly used new guards.

I've started going through the brakes. The PO introduced DOT 5 into the system without a complete flush. I have to drain/flush the entire system. I'm also replacing the flex lines. Anyways, here's a pic of the start...



With the limited time I drove this rig, the brakes felt fine. I've had folks suggest replacing the M/C. I'm not one to replace parts just because... Do these M/C's have a history of failure? I don't plan on racing.

[jkh2cpu]

You will need to carefully inspect the steel brakeline that exits the car from the tunnel. That area can be exposed to road debris including rain water and salt, if the car has been driven in the snow. On my 1973 911, the line exits toward the bottom on the tunnel; Porsche late moved the exit to the top of the tunnel. Any way, if that steel line is rusted, expect that it may spring a leak when you are really applying the brakes. (Been there done that)

As for the master cylinder: I'd change it out after 36 years. You don't want to find out that it is not working properly after you loose your rear brake circuit as mentioned in the above paragraph. (Don't ask how I know)

If the calipers are not frozen, you should be able to rebuild them: it's a simple process spelled out in many places. If they are working, you certainly want to 'exercise' calipers to get the pistons moving a bit more freely. I read in Pano 30 years ago to jack an end up, return the pistons to their fully retracted position (press them into the calipers, taking care that the brake fluid overflow line attached to the brake fluid reservoir is attached and exiting the car body), remove the pads, put some wood in the spot where the pads go, and step on the pedal until the pistons hit the wood. Repeat this process two or three times for each caliper on the car. You'll know if you have pistons that do not move. But really before you do this, you want to pop the pistons, inspect them for rust, clean them up with fine steel wool if necessary or possible, replace the o-rings that support the pistons in the calipers, and put them back together. It should take 15-20 minutes per piston.

HTH.

John.