ivai

Hey all,

I just figured out a no-start/poor run issue related to injectors after a semi-rebuild/upgrade of sorts.

Here's the quick break-down:

New rod bearings, but mains and rings have 130k miles on them (bores looked good, and my budget was tight so I didn't spend the extra $$ on rings/mains/machine work)

New 930 clutch disc, KEP Stage I pressure plate, and Fidanza flywheel.

Now I can just barely shift it into 4th gear while pushing the clutch pedal all the way in... but not 1st. If I put the car in first, push in the clutch, and start it.. it will start and run, its rubbing enough to barely move the car though.

I remember seeing that Chris white had this issue on a customer's car a few months ago -- it ended up being the thrust bearing (crank was moving back and forth too much). I checked for crank walk before I put the engine back together, and it was within spec.

Anyways, I guess because I have a slightly worn thrust bearing, the flywheel and clutch are just barely not clearing one another..

Yes, I've made sure my clutch pedal is extended all the way. The throwout fork lever is physically touching the bellhousing when I push the clutch pedal all the way in.


So. My question is this: What options do I have?

These are the options that I see, listed in order from easiest to harde$t:

1.) Try filing down the bell housing and/or the clutch fork lever a bit and see if I can get some more throw out of the pedal.
2.) Put the car in first gear, start it, rub the clutch a bit and see if I can wear it down enough so that it will shift properly.
3.) Take apart the clutch/flywheel assembly, and have the pressure plate or flywheel machined down a bit.
4.) Pull engine and replace the main bearings.

Thanks

ivai

Couple other things:

Spec for crank play is .015", mine was less than .005"

Is anyone successfully using a Fidanza flywheel, new 930 disc, and KEP Stage I pressure plate?

Thanks.

TRP951

try bleeding the slave cylinder again and then bleed it some more

hot-J

I just went through this after a rebuild. I dont know what exactly fixed it, but heres what I did;
#1 Relpaced flywheel bolts (thought they might be TQ's incorrectly after rebuild) Bled the S#!T out of the clutch....No fix
#2 Replaced pressure plate Bled the S#!T out of the clutch......... no fix
#3 Replaced Clutch Master cylinder Bled the S#!T out of the clutch......no fix
#4 Installed new PP, flywheel, disc, slave cylinder, hard AND soft lines from clutch master to slave....
That fixed it......Oh, and inbetween all "steps", I Bled the S#!T out of the clutch.........

DDP

It's always the same answer, bleed the slave again. Then bleed it more. Then when you're tired and sick of bleeding it, bleed it one more time.

porshhhh951

I concur. I had the very same problem on mine. It was bled multiple times before the problem was finally fixed.

aribop

Jeff, do you have a Motive Power Bleeder? If not, I do and we can get that sucker bled correctly!

Skip Wolfe

I had this same problem an it turned out to be one of the fingers on the clutch fork was broken - cracked and bent back. I would bleed it again using the Motive power bleeder and it that doesn't work pull it apart.

ivai

Hi, yes I do have a Motive power bleeder and that's what I used.

I just checked and the end of the clutch fork (where its being pushed by the clutch slave cylinder) is definitely hitting the bell housing. There's about 15-16mm between the end of the clutch fork and the bell housing.. Clarks-garage says 18mm for a new clutch.

I think I've read somewhere that the 930 disc is 1mm thicker than stock.

Is anyone using this same setup successfully? Fidanza flywheel, 930 disc, KEP PP.

Thanks.

PS -- I'm going to be out of town for a few days starting tomorrow morning. Hopefully I can resolve this late next week.

Droops83

Bleed the clutch manually at the hose that comes out of the master cylinder, where it connects to the hard line that goes down to the clutch slave cylinder, in the engine compartment (EDIT sorry I misnamed this hose when I first posted!) at the firewall. It is a bit messy, stuff the area w/ rags. You'll need 2 line wrenches, an 11 mm and a 17 mm IIRC. Don't crack the line connection loose till your helper has the clutch pedal all the way to the floor (this is very important!!) and of course close it back up before they let up on the pedal. Do this several times and you should get any remaining air there. Rinse the area with water when you're done if you made a mess.

Not only is this is the high point in the clutch hydraulic system, there are sharp bends in these lines that trap air and I usually find that pressure bleeding at the slave cylinder alone is not enough. I use this method on every 944/968 I have ever bled and it works every time (I work on Porsches for a living). Try this first before you go any deeper. If this doesn't help, your problem is elsewhere.

---Chris A.

ivai

The slave cylinder not being bled well enough is not my problem right now. The clutch fork is hitting the bell housing, i.e. it doesn't have enough room to travel fully.

Some thoughts..

-Perhaps my clutch fork is too worn, or is bent.
-Maybe the clutch fork needs more material than stock where it contacts the throwout bearing to give it more space
-Maybe I need some kind of spacer/washer on the throwout bearing.

TRP951

Did you assemble the throw out bearing correctly? I have the KEP1 and the 930 disk and mine works fine so fork travel shouldnt be a problem.

hot-J

Fork could defenatly be bent, release bearing might be bad, is the PP flywheel and disc new? If All are not new, a reserface might do it.

ivai

Tim, I wonder if the Fidanza flywheel in combination with the KEP1 and 930 disk could be causing the issue.

PP flywheel and disk are all new, throwout bearing is new also.

hot-J

What about the release bearing on the PP?