Question for the MFI people out there...

[bbthomson]

Thanks Guys,

I am hoping that this has nothing to do with the engine...it is new and I paid allot for it, so the thought of having to dig in to it at this point is close to inconceivable. I will start to look at the top of the engine and the 5 or so possible obvious candidates. (Oh sweet, sweet denial...)

Any idea why there is no crank. It is dead. The fuel pump is working but after that, there is nothing?? Thoughts?

Brent

[Early_S_Man]

Brent,

Check both 14-pin connectors for start signal on the #1 Yellow wire going to the starter solenoid.

[bbthomson]

Hey Warren,

I checked both 14 pin connectors...no signal on either. I also checked the fuse box and there are no blown fuses.

Any thoughts?

Thanks,

Brent

[Early_S_Man]

Brent,

You may have had a failure in the electrical portion of the ignition switch!

There are only two other connections between the ignition switch and the forward 14-pin connector ... a single pole, and a 6-pole ... shown in the following diagram:

[bbthomson]

Hey Guys,

Take a look - something appears to be very off here as the #2 rocker appears to be pushed out. I also cannot move the engine by hand whatsoever. This is not looking good...

Brent

Someone please tell me this is not what I think it is...

Thanks,

Brent

[bbthomson]

Ok Guys,

I was premature with my previous post...I used the search button and did allot of reading.

Tonight, I decided to not get beaten and dig in to what I was avoiding. This is my hobby and need to remind myself of this occasionally.

I removed the spark plugs and drained the oil. From there I could manually turn the engine by hand. All seems fine.

I decided that I would inspect, clean up and replace any potential oil leaks as monitoring oil consumption while losing significant amounts of oil on very short drives is not logical.

I also will need to figure out my starter issue. Albeit a pesky problem, it appears as though it can only be caused by a limited number of things.

Potential oil leak problem:
1) Rocker arms - upon initial inspection of the upper & lower rockers - all appears to be fine. There is a tiny bit of side to side play (Loose) in both the upper & lower # 2 & 3 cylinders.

2) I inspected the MFI pump. There appears to be no leaking from any of the covers.

3) I inspected the oil breather cover - there is oil spray coverage all over this general area so I will replace this seal.

4) Removed the oil preassure line to MFI pump & oil preassure sender. Will replace both. Can't tell if they are leaking but once again, they are covered in oil.

5) Removed & Inspected small overflow hose from pump to breather cover. Appears to be in good shape.

6) Is it common that the main oil line from the oil tank to the drivers side of the motor leak? you will see that there is a wear mark in one of the pictures as this hose leans against the drivers side HE.

7) Removed Drivers side HE. Will need to clean. Not a ton of oil inside but there is some. Any ideas on the best way to clean? Break cleaner and then rinsed properly with water?

Where would I find the banjo bolt? (Have not figured that out yet.)

Here are some pics...maybe you can see something that I can't.



Thanks for listening...Let me know if there is anything, I may have overlooked.

Thanks,

Brent
______
70'- 911

[Early_S_Man]

Brent,

Here are a couple of views that may help with the banjo bolt underneath spark plug air seal #1:





It may be coming down from above, but there is a noticeable oil droplet forming on the scavenge line hose:

[bkreigsr]

wow, what a shame.
that engine is nice stuff.
I can see how you'd be so disappointed.
with a leak so big, something has got to jump out at you, no?
part of this hobby stuff has to be enjoying the fruits of our labors.
keep at it.
Bill K

[Grady Clay]

Brent,

Just to be clear, was the removing the sparkplugs and draining the oil associated with the engine being able to turn? Was a cylinder hydraulic locked with oil or fuel?

Was there any sign of oil in the air filter assembly? If the oil sump tank overflows from too much oil, it can drain from the air filter assembly onto the breather plate unless the drain hose is connected.

To add to Warren’s great list; the lip seal at the left cam drive can leak. The MFI pump belt can then carry the oil up to the top of the engine and sling it around the area of the oil pressure sender, breather cover, MFI pump oil lines, etc. Many times this is caused by the drain hole between the cam bearing and the lip seal being plugged with sealant. This allows pressurized oil to be present at the seal and cause it to leak. Check to see if the belt is oily.

A less likely candidate is the seal at the drive shaft in the MFI pump.

Cleaning the oil mess is best with solvent. You can finish with brake clean in many places and soap & hot water.

Looking at your first picture of the #2 intake rocker, I would have guessed the shaft wad out. The later pictures clearly show it in place.

As I said before, use this as an opportunity for some early maintenance. Cylinder head nuts, rocker shaft bolts, cam timing and valve adjust.

Hang in there, even the simplest of things can cause you stress during this period.

Best,
Grady

[bbthomson]

Hey Grady,

Yes the draining of the oil and removing of the spark plugs appears to be related to being able to turn the engine.

Does this mean that the engine was overfilled with oil/fuel?

No - there is/was no signs of oil in the air filter assembly.

The MFI belt is oily as everything in the general viscinity is oily. It is hard to tell if the MFI belt is throwing the oil or not but it does have some oil on it.

As I can't seem to locate exact location of the oil leak my gut is telling me to replace many of the items on the collective list. Does this seem like a logical plan?

Thanks,

Brent

[Grady Clay]

Brent,

“Yes the draining of the oil and removing of the spark plugs appears to be related to being able to turn the engine.”
About the only way this can happen is for the cold start solenoid valve to not be shutting off. While running this might only be a very rich indication. If the electric fuel pump was running but the engine not, the engine could hydraulic lock from gasoline.

If the engine is let set for some time, the gas can seep past the rings and into the crankcase.

If the oil is seriously diluted with gasoline, the thin mixture can readily leak.

Disconnect the hose from the outlet of the cold start solenoid valve and run a long small ID hose to a container on the ground. Operate the cold start and then let set with the electric fuel pump running. The valve shouldn’t leak. Be aware that when you operate the cold start it will put some fuel in the hose and it will drain.
Be very careful with gasoline. It would be advisable to disconnect power to the CDI. Do all this out of doors and away from your house & garage.


“As I can't seem to locate exact location of the oil leak my gut is telling me to replace many of the items on the collective list. Does this seem like a logical plan?”

Yes, this is about the only way to approach this. Replace as many of the inexpensive things as you can all at once. Be sure an thoroughly clean up all the leaked oil, particularly from where it might have pooled. You don’t want old residual oil to fool you.


Another thought; blow through both the breather hoses to and from the oil tank and the breather plate. Check the flame arrester at the connection to the air filter assembly. If there is a restriction in the breather system, particularly with fresh rings, it will force oil out everywhere.

Best,
Grady

[bbthomson]

Hey Grady,

I will do as you suggested regarding the fuel. My cold start is not always on as I have a remote switch that sprays a small amount of fuel into each throttle body.

The oil does not appear to be seriously diluted. There is a very mild gas smell in the oil but that does not surprise me as I know my car is running rich.

Thanks Grady, Warren and Bill...much appreciated!

Brent

[bkreigsr]

Brent, don't thank me. I'm sitting here with my chin on the ground, overwhelmed by how much I don't know about the system. Thankfully, mine ran like gang-busters from the get-go thru 2 rebuilds, with a little tweaking here and there.

[bbthomson]

Hey Guys,

I oedered many of the basic maintenance items this afternoon and continued to try and determine where this oil leak is coming from...still nothing concrete as it could be from a couple of different sources.

I had a spare scavenge oil line laying around that is virtually vrand new so I am going to replace my current line. Is there anything special that I need to do to install? I did a search and was looking through my books but did not find anything. I believe this is a relatively low preassure hose but are there any special torque ratings that I should adhere to? Do I have to smear any anti seize or loctite on the nut that goes in the case?

Thanks,

Brent

[bkreigsr]

Brent, a couple of rounds of teflon tape should be okay. I'd stay away from the anti-seize and lock-tite.

[Grady Clay]

Where the fitting threads into the case, the sealing is with the 22x27 mm aluminum crush washer (900.123.011.30). Nothing extra is needed.

Where the hose/pipe fitting connects to the screw-in fitting, no special sealant is needed. It seals metal-to-metal on the ball and socket of the fitting. It is good to visually inspect those surfaces.

The historic weak link is where the rubber hose is crimped onto the steel fitting.

I have always been leery of using Teflon tape. I’m afraid of a bit getting in the oil system and restricting a cam spray bar orifice or worse.

Best,
Grady

[bbthomson]

Thanks Grady,

Yes - the best that I can come up with is that the oil was leaking from the crimped end of the scaveng hose spraying out and upwards....from there, oil would get onto the MFI pump belt and spead it onto the top of the engine.

Of course this will only be determined once I replace all of the usual suspects, clean up and get the starter problem solved.

Luckily - I have a spare oil line, so I am going to replace this tonight and begin the cleanup and start to put this thing back together.

Question: I retorqued the lower rocker shafts last night and there is no difference in the amount of play in the arm. This 'play' is very slight but it is not present on all rockers. Should I check valve clearance?

BTW - Thanks allot for all the help...when I started this project over a year ago, I envisioned digging in and learning how to do all of this...the hardest challenge is getting over the massive learning curve which is still there but at the very least, I am gaining confidence and have little fear of getting in over my head which I can thank you guys for...Once again, my sincere gratitude.

Brent

[Grady Clay]

Brent,

“Question: I retorqued the lower rocker shafts last night and there is no difference in the amount of play in the arm. This 'play' is very slight but it is not present on all rockers. Should I check valve clearance?”

There isn’t any relation between the torque of the rocker arm shaft and the side play of the rocker arm. The torque on the hardware for the shaft causes the shaft to expand in the bore of the cam housing (Porsche calls this “…wedge effect of bolt.”) This is what holds the shaft in place axially and supposedly seals the oil in (another subject). You can get a big oil leak here if the shaft has slid out of one side.

The side play of the rocker shaft is specified installed at 0.100 mm minimum and installed at 0.350 mm maximum with the wear limit of 0.500 mm. As you can see there is quite a range. There basically isn't any relation between side play and valve clearance.

The bearing clearance between the rocker arm bushing and the rocker arm shaft is much tighter. The specification is installed clearance 0.016 mm minimum and 0.035 mm maximum. The clearance wear limit is 0.080 mm. This is part of the clearance you set when adjusting the valves to 0.100 mm clearance.

While you are there it never hurts to check the valve clearance. Slightly too loose is only noisy. Too tight can cause problems with a valve not setting on the seat and bad things can happen.

Best,
Grady

Edit for a little more detail.

[bbthomson]

Hey Guys,

Quick update. I have replaced all possible leaks. Cleaned up the engine and done some tightening of bolts and checking of valve clearances etc...all seems to be good on the oil leak front. (For now?)

Now I need to drive the car to verify that I have fixed the problem. I can't as the car does not turn over. It is now time to tackle the starter problem - I have done the following;
-Checked the battery and connections. No corrosion whatsoever but I cleaned anyways.
-Lubed ignition.
-replaced electric portion of ignition.
-Inspected and replaced all grounds (3)

No difference...it still won't engage the starter.

I just tried to engage the starter by connecting directly to the battery to verify if the starter was working but it did not do anything. My first inclination is to ask if I am doing this right and if so, I think I may have found my problem. (Dead starter motor) To engage the starter directly, I ran a wire from the positive from my battery to the positive on my starter. I tried to turn the car over and nothing happened. Based on my understanding the starter should have engaged immediately upon connection. (Yes/no?)

Thoughts?

Brent

[Early_S_Man]

Brent,

No. You also need to temporarily connect 12 Volts to the small Faston tab on the solenoid where the Yellow #50 wire goes. That is needed to operate the solenoid.