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-   -   Finally getting around to CMA on my MFI (http://forums.pelicanparts.com/porsche-911-technical-forum/399457-finally-getting-around-cma-my-mfi.html)

Grady Clay 05-23-2008 09:56 AM

Quote:

Originally Posted by declang (Post 3960088)
Must say it was much harder to start now without the cold-start hooked up !


Good, that is an indication that the mixture isn't way too rich.
Too often someone has set the mixture so rich that the cold start is unnecessary. :eek:
The fact that you were able to start it at all says it is richer than it will be when finished.

Best,
Grady

declang 05-23-2008 11:03 AM

I'm getting excited now. I'm within shooting distance of the goal :)

I do have two oil leaks from the lower cam covers, dripping down onto the ssi's so I guess I'd better cure those before I smoke myself out of the garage !

I have an oil leak at the upper cam cover beside #1, and I can't tell if it's from the banjo fitting or from that corner of the cam cover. I'm thinking banjo, mabye it should have had new crush washers ? I simply refitted the banjo with the old washers - what looked like plain flat aluminium washers.
Although, thinking about that, the banjo at #4 doesn't leak, and it was fitted the same way.

Thats all I have to report for today. It's now Friday evening here, so no more work until tomorrow sometime, if I get the chance.

Grady Clay 05-23-2008 02:44 PM

Declan,

The salt water in the ‘pond’ conducts electricity. I suspect the ‘excitement’ makes it to the East Coast. The Forum carries it West. :D

When you have an oil leak in the cam area and have the valve cover off, always check the rocker arm shafts. Porsche specifies they be torqued at every service. Most ignore this. As I remember Pelican copper (from near London, Ontario) had a rocker shaft slide out just south of the NY border a few years ago (not his fault). Any time you are chasing an oil leak in the cam housing area, this is a ‘must’.

Best,
Grady

declang 05-24-2008 03:30 AM

My suspicions about the banjo leaking were correct, I think.

The washer between the banjo and the fixing point was *just* too small for the banjo bolt. It fiited on the threaded part of the bolt, but would not go any further onto the bolt, so tightening the banjo bolt would never get a good seal between the banjo fitting and the hex mounting point. (Not explained very well, but hope you understand !)

Hopefully thats cured now.

Edit:
The banjo washer gave me some trouble.
I ended up dremelling a little off the ID of the old aluminium washer to let it fit the bolt better, and than sorted it.

Still have leaks from lower cam covers. I re-torqued all the nuts, and it reduced the leak a bit. need to revisit that.

declang 05-25-2008 11:26 AM

I had an aborted attempt today at adjusting part-load mixture.

I had the car idling nice & smoothly, a bit rich on startup until the stat got some heat, then settled into a nice smooth idle around 900/950 rpm.
I don't think the car has ever idled for so long before !
I still had a few oil drips from the lower cam covers, but nothing too bad.

So, I hooked up the LM1 with the exhaust clamp & went off for a drive.
Bit of smoke from oil being burned off the heat exchangers - OK, expected that.
Kept an eye on the afr, seemed a bit lean & was getting lean popping.
Stopped at the side of the road & richened the part load 2 clicks.

Thought there seemed to be a lot of smoke in the engine bay, but OK, probably coming off the heat exchangers. Just let it burn off.

Back in the car, turned around & headed for home. Loads of smoke coming from the air vents. I mean loads. I had to stop twice to let the smoke clear before I got home - only about 2 or 3 miles !

So, I'm trying to figure out where all the smoke is coming from.

Before I started on this CMA route, I wanted to check if hot air was getting to the stat, so took off the air filter housing and went for a drive to warm it up.

Unfortunately, I didn't plug the two pipes that I removed from the rear & underside of the housing. One large pipe from the oil tank, one small breather of some sort.
During that drive, quite a bit of oil was spat out onto the top of the engine block. (so much so that when I returned & parked in the garage, I nearly had a heart attack to see so much oil dripping onto the floor, until I realised my stipidity)

I simpy mopped up the excess oil but I never removed the tinwork.

I'm thinking mabye there is still a lot of oil sitting on top of the block, which is smoking when it gets heated, and that is the same aire which is getting blown through the heat exchangers, into the cabin.

Is my logic right ? The air that enters the cabin, through the heat exchangers, is what gets blown down the two pipes at the side of the engine fan, so if there is a lot of oil smoke in the engine bay, it gets blown into the cabin ?

What is throwing me off is that this didn't happen when idling, only at faster engine speeds while driving.

Any suggestions ?

Grady Clay 05-25-2008 11:57 AM

What is the oil level (measured with the dipstick)?

There can be some serious issues measuring mixture if the oil is getting into the air cleaner or excessive blow-by.

Am I correct, we havent solved the #5 cylinder leak issue? Could this be related?

In any event, cleaning up all the spilled oil will help with better diagnosis.

Best,
Grady

Back to the better than most Indy but way too many stupid crashes.
G.

Flieger 05-25-2008 12:44 PM

Quote:

Originally Posted by Grady Clay (Post 3963521)
Back to the better than most Indy but way too many stupid crashes.
G.

I thought Monaco was pretty interesting in the wet without traction control. All the hot shots like Raikkonnen were spinning and crashing. Kubica did a fine job for BMW with no incidents.

Nuerburgring 24 Stunden was a good result, too. Porsches 1,2,3,5,7,8,9,10. Reminds me of that Monza 956 poster. The 2 other cars were hot BMWs. I wish I could see some of the action and record it. I guess photos will suffice.

declang 05-25-2008 01:47 PM

Quote:

Originally Posted by Grady Clay (Post 3963521)
What is the oil level (measured with the dipstick)?

Halfway between min & max.

Quote:

Originally Posted by Grady Clay (Post 3963521)
Am I correct, we havent solved the #5 cylinder leak issue? Could this be related?

I haven't checked leakage or compression since I got it running. I was hoping to do an italian tune-up, then check again, but haven't done that yet.
Quote:

Originally Posted by Grady Clay (Post 3963521)
In any event, cleaning up all the spilled oil will help with better diagnosis.

.
Yep. Looks like I need to do that.

Are there any pointers for getting the air-shroud/tinwork off.
Do I need to remove the TB's & the mfi pump ?

Will have a better look tomorrow.

Cheers.
Declan

edit : Had a look at the PET diagrams & looks like the TB's have to come off to get the air shroud off.
I presume the pump will have to come off as well, so I'm off to search for threads on how to do that.

declang 05-26-2008 01:50 PM

Well, I had a good poke around this evening in search of my oil leak(s).

As far as I can tell, & see through the fan, there is no pool of oil on the top of the engine block. It all seems quite clean in there, so I'm going to hold off on removing the mfi pump and throttle bodies just yet.

On the 4-5-6 side I have a substantial drip from lower cam cover. There is a big drip about every second or so onto the ssi. The smoke from this is passing up into the engine bay past the rubber seal (beside the upper cam cover).

I did tighten all the nuts on that cover, a few times, now they are as tight as I dare, but still seem to have the leak from the top edge of the cover, which then finds its way down along the cover surface & eventually drips off the ends of the lower studs/nuts. Looks like the studs themselves are leaking, but its coming from higher up.

Don't really know what to do about it. Should I have used some form of sealant when replacing the cover ? It was new gaskets, and the mating surfaces were cleaned.
I keep thinking of the rubbery sealant stuff I removed from inside the cover - as if a bead of sealant had been applied the last time the gaskets were done. I know the car had a professional valve adjust shortly before I bought it.
I also have wetness from one of the nuts on the upper cam cover, but it seems very slight. more an oil dampness than a proper leak.

On the 1-2-3 side, I have a similar leak from the lower cover, again dripping down onto the ssi. What I don't understand, though, is why I am seeing so much smoke coming into the cabin from this side. ( and none from the 4-5-6 side). The ssi's look in perfect condition, but I guess its possible there is a hole in the top that I cannot see, which is sucking in the oil smoke.
The amount of smoke is simply amazing. It just wafts up out of the windscreen vent. You would think there was a fire in the dash somewhere. (I checked, there's not !)

I also have a small leak on the upper side - It's either from the bottom edge of the upper cam cover, or its still from that banjo where I had the trouble with the washers.
It's not a lot, but enough to wet the length of the sheet metal that seals between the upper cam cover and the bodywork. It could still be the banjo, although I checked for leaks there with some tissue paper under the banjo, but only at idle. I think the leak only shows up at higher revs.

Again, I don't know what to do about that.


Any suggestions are more than welcome.

Cheers.
Declan

declang 05-27-2008 02:19 AM

Amazing what results a search for "oil leak" on this forum will generate !
I strongly suspect my leaks are from the valve cover gaskets.
I also see there are a few options from our host.

I have bought & used the complete kit : 10-0906-091-M260

There is also a complete kit 10-0906-092-M260 with a silicon bead on the lower gaskets.
Then there are the fully silicon gaskets PEL-SIL-VLGK, and also individual Victor Rheinz gaskets.

After reading a lot of the threads, I'm still unsure what to do.
Is there a preferred method ?

I also noticed when removing the lower covers there was some sort of sealant on the studs (as well as on the gasket surface), but I can't see how that would be necessary.

So, what is the "done-thing" for the cam cover gaskets.
Install them dry ?
Use a bead of sealant (loctite 574/silicon/other) ?
Use silicon gaskets ?

Cheers.
Declan

SP2 05-27-2008 06:12 AM

John Walker has me spray both sides of the gasket with copper gasket spray. It is sticky when dry and he does that on all his paper gaskets. I also fine sanded the covers flat with sandpaper on top of a sheet of glass. Hope this helps.

declang 05-27-2008 06:31 AM

Yes indeed it helps. Thanks James.

I've read nearly every thread on here and on some other Porsche forums about the gaskets & leaks.

I noticed the oil return tubes mentioned as as source of leaks which make their way to the heat exchangers, so I must investigate further this evening.

I've also learned that I may have over-tightened the cam cover nuts, which can make my problem worse instead of better.

I'll post later when I've had another look

declang 05-27-2008 11:13 AM

Right, I got under this evening and had a good look at the oil return tubes, and everything else under there.

Both return tubes, on both sides had a good coating of fresh oil on them. The #2 and #5 cylinders seem to have a lot of burned oil on the fins - quite black & sticky.
I cleaned them a bit, and cleaned the oil return tubes, and also cleaned as much of the heat exchangers as I could get to.

I did notice the access holes (for the studs) through the exchangers were very oily, and the bottom surface of the exchangers had a fresh oil coating spreading outwards from these holes. Guess I need new oil return tubes.
It does have the collapsable tubes, so I thought mabye just replace the seals, but I don't think I'd be able to get a circlip pliers onto the clips to remove the tubes intact, or is that possible ? I can see the clips & reach them with my fingers.

The nuts on the exhaust studs looked quite rusty, so I hope I can install new return tubes without having to remove them.

I also have a drip from a couple of the lower cam cover nuts. It seems to be leaking out the stud, but I can't be sure. The studs did have some sort of sealant on them which I noticed when removing the covers.

(Should I be posting this oil leak stuff in a new thread, to keep it out of my cma/mfi thread ?)

Flieger 05-27-2008 12:33 PM

Sounds like you might want to go ahead and do a proper engine drop. That makes it easier to find all the tough leaks like the MFI pump drive belt and rear main seal. It is also the only way to properly replace the oil return tubes, unless you go with the collapsable temporary fixes.

declang 05-27-2008 01:18 PM

I thought the collapsable return tubes were a permanent replacement ?

Flieger 05-27-2008 04:20 PM

I guess you could run with them for a long time like some people do. Eventually, you should put in solid ones, though. The 2 piece last a while but will leak oil more than the factory spec 1 piece units. They will get you to the next engine drop or when you want to pull the cylinder heads. If the only problem with the engine is the leaky tubes the 2 piece make sense. The factory single tube design has fewer places to go wrong.

Jeff Higgins 05-27-2008 05:41 PM

You can easily fix everything that might be leaking oil onto the heat exchangers with the motor in the car. The first thing to do is to get those heat exchangers out of your way. Drop the whole exhaust system; it will make some of the oil leak fixes easier. Hit all of the nuts with PB Blaster or something for a few days before you try to loosen them.

You should be able to spin the return tubes so that you gain access to the circlips. Use a well padded pair of channel locks or vise grips if you have to. Just put new o-rings in the ones you have and reuse them; they should remain sealed for a good long time. Use some high temp silicone grease on all of the o-rings.

While the return tubes are out, go ahead and reseal the crossover oil return line where it goes into the forward left case. This thing is darn near impossible to work on with the return tube in the way, so take advantage of the fact it isn't. Take the compression fitting apart, then take the fitting out of the case and put some plumber's teflon tape and RTV sealer on the threads and screw it back into the case. The compression fitting doesn't use any sealer, but rather some anti-seize so you can get it apart later if you ever have to.

On the right side, remove the long piece of tin, the forward piece of tin (next to the bell housing) and the shroud screws that go into the oil cooler. Take the "J" pipe off that goes to the tank, and remove the oil cooler. Replace the seals inside of there and remount it. The seals like to fall off when they are horizontal in the car, so "glue" them in with some of that sticky silicone grease you used on the return tube o-rings.

If you have not replaced the thermostat o-ring, do that too. And the breather cover gasket right next to it. Take the oil temp and pressure senders out and put some plumber's tape on their threads, being careful not to cover the openings in the ends. The pressure line to the MFI pump under the temperature sender likes to leak, too, so put a couple of new compression washers on it.

When your valve covers are off, you have an opportunity to seal up the rocker shafts. If they don't already have them, putting in some RSR seals would be a good idea. With any given cylinder at TDC as if you are setting its valves, you can loosen the rocker shafts on it and slide them out into the "dry" areas of the cam towers and put those seals into the grooves. Remember to turn the nut only, not the screw, when loosening or tightening those rocker shafts.

When putting the valve covers back on, don't over tighten the nuts. They have a very low torque value (I think something like 8 ft lbs?). That's why they have the nylock nuts - so they don't rattle loose from that low value.

Make sure the MFI pump is not leaking as well. The baseplates sometimes leak. The oil supply and return lines sometimes leak. If the baseplate is leaking, you have to remove the pump to fix it. I'm not sure that base gaskets are even available; maybe Pacific Fuel Injection or Henry Schmidt has them. I just reuse mine with a healthy coating of silicone RTV.

The pump drive on the forward end of the left cam can leak as well. Yes, it can be replaced with the motor in the car; I've done mine and several buddies'. Take the left rear wheel off. Remove the drive pulley and belt, marking the pulley's orientation (after lining up the "FE" mark on the crank pulley). Remove the forward piece of tin (you have to take the throttle rod off first; it passes through a slot in the tin). From there it is a "simple matter" of prying out the old seal and pressing the new one in. I use a bunch of hooked dental picks to pry the old one out. It doesn't have to be pretty... The new one just presses in with finger pressure. Just make sure it is straight and flush all around. Make sure you line the pulley up the same way it came off; it only uses two of the four holes, and they are not 90 degrees to one another. They are clocked half a tooth off, to allow for that fine of an alignment with the timing marks.

Anyway, that should take care of most, if not all, of your leaks. At least the ones dripping on the heat exchangers. Once you are done with all of that, your tuning efforts will be much more pleasant.

declang 05-28-2008 01:05 AM

Thats a great explanation Jeff. thank you.

I'm still a bit hesitant to tackle those rusty nuts on the SSI's, but I guess they'll have to come off sometime.

Guess I need to go and order some o-rings & gaskets from our host.

I managed to find a 2-bar fuel pressure gauge from Simtek Motorsport Electrical, so ordered one, but will be about a week or so before I get it.
(For reference, on simtekuk.co.uk it is described as a 52mm Mechanical Fuel Pressure gauge, GAU-054. The photo shows a 7-bar face, but it is actually 2-bar. GAU-053 is the 7-bar version)

I also got a reply from Koller + Schwemmer, and they can test the injectors, so I'll send them off while I'm waiting for the other bits & pieces.

For reference, I simply emailed info@koller.de explained what I had, and asked if they could test them. They confirmed they can & quoted a ballpark price of €100 for the 6)

Cheers.

declang 05-28-2008 01:59 PM

In the spirit of Pelican, I just ordered all the gaskets, o-rings, seals, etc from our host, and remembered I had a discount certificate, which almost offsets the postage cost to Ireland :)

I have the injectors all numbered, bubble-wrapped & safely packaged up for posting tomorrow to Koller + Schwemmer.

I also ordered 10m of fuel hose (from the UK), with a t-piece for the fuel pressure gauge which has 1/8NPT thread, some anti-seize & some Hylomar silicone stuff.

Miraculously, I also have a US gallon can of Marvel Mystery Oil ! Could not find it anywhere in europe, & got no response to several emails to the relevant companies for seafoam & marvel mystery oil. I mentioned the name in passing to a fellow porsche-aholic & he just happened to have some !

declang 06-03-2008 05:12 AM

Koller + Schwemmer have tested the injectors.

They all open too early - 13-14 bar. (188 - 203 psi)
Spec is 15-18 bar.

I'm going ahead & getting 6 new injectors.


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