BIB5566

[Nine One One]

Well done! some good old school tinkering, methodically thinking everything through. You have probably learnt a lot, published it all, warts and all, which will be very helpful to others in the future, and a joy to read.

[hot66]

Nice one

That thermostat has caused many problems with cars I know over the years , mine including when the circlip holding the discs to the shaft popped off and it went full rich / undrivable

[210bhp]

The fact that you had to go 18 clicks on the main rack suggests to me that someone else tried to solve this issue going about it the wrong way so kudos to you for thinking it through logically. This also suggests that you would have been unlikely to throw the problem to a garage to sort out.

The small nylon part that you carefully modified to work, this is a ‘square peg in a round hole’, correct?
You would have thought that wear would have made it sloppy rather than tight so do you think the nylon part would have rotated slightly in its position and hence found a very slightly tighter part of the bore to become sticky in its operation? Or did it wear unevenly at each ‘corner’? Interested to know how you think wear affected it’s operation.

Regards
Mike

[Lancsbob]

Well done son!

[knapmann]

That's great news! Enjoy for now and continue the shakedown but then it is well worth revisiting a bump in the advance map.

I will do Jonny, Im looking forwards to doing some tweeking now the basics seem sorted!

Brilliant.
Really good to see logical step by step problem solving and learning getting it fixed.

Unfortunately I don’t think the garage exists that are prepared to put this much time (and more importantly the hours of thinking) into this type of thing to really get to the bottom of this.

You are now the expert!

Hopefully it might help someone else one day! And you are right I contacted some local Porsche garages who just said they wouldnt even look at it. And the ones that would probably dont have any more of an idea than me. It would have been a heafty bill trying to diagnose and fix these issues. I hope my new found knowledge will stand me in good stead in years to come!

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An excellent result !!

It just shows what a logical mind combined with a refusal to accept defeat & a 'what's the worst that can happen ?' approach can achieve ... well done !!

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Well done! some good old school tinkering, methodically thinking everything through. You have probably learnt a lot, published it all, warts and all, which will be very helpful to others in the future, and a joy to read.

Thanks Guys!

Nice one

That thermostat has caused many problems with cars I know over the years , mine including when the circlip holding the discs to the shaft popped off and it went full rich / undrivable

I bet you had fun trying to solve that one!

The fact that you had to go 18 clicks on the main rack suggests to me that someone else tried to solve this issue going about it the wrong way so kudos to you for thinking it through logically. This also suggests that you would have been unlikely to throw the problem to a garage to sort out.

The small nylon part that you carefully modified to work, this is a ‘square peg in a round hole’, correct?
You would have thought that wear would have made it sloppy rather than tight so do you think the nylon part would have rotated slightly in its position and hence found a very slightly tighter part of the bore to become sticky in its operation? Or did it wear unevenly at each ‘corner’? Interested to know how you think wear affected it’s operation.

Regards
Mike

Hi Mike, Thanks for the comments, yes I think someone must have tried to compensate for rich running caused by the fuel pressure or the thermostat by adjusting the main rack excessively. The odd thing was the thermostat adjustment. It was way off, but it was very deliberately set where it was with the adjusting screw locked off with a locking nut. This partly lead me to to believe to date that it must be set right but obliviously not.

Yes its a square peg in a round hole. Yes I would have thought the same that it would go sloppy if anything and you are right, the 4 corners leave wear marks on the bore of the fitting. You might be right that maybe it rotated inside the bore, possibly when I was actuating it manually to clean it out, I didnt manage to clock this when I took it apart is the spring fired it out when I opened it up. In theory it should work in any position in the bore really I would think.

What I noticed on mine was that it would move fine when perfectly "square" in the bore. However if it kinked over in the bore any, (which the spring allows it to do), then it would stick. If you look at the nylon piece the 4 corners have quite sharp edges, so when it goes out of square in the bore you can see why it would bind. I rounded off these edges with the sand paper so that it wouldnt bind up even if it kinked over in the bore. This was basically the problem. Quite why this has happened when no one else seems to have issues with this valve I dont know.

Well done son!

haha! Thanks Dad for all your support over the years! I appreciate it really

[deano]

Genius!!

[911hillclimber]

Nice job done.
Do you think you are the first to visit the pump?

[knapmann]

Nice job done.
Do you think you are the first to visit the pump?

Hmm i doubt it, its been around for 52 years now so im fairly sure someone would have had a fiddle with it in all those years!

[hot66]

The manual enrichment thermostat is a bit of a giveaway it been messed with in the past

[neilbardsley]

Congratulations

Sent from my Redmi 7 using Tapatalk

[sladey]

Nice work - well done and thanks for sharing

[911SE]

Thanks for sharing and very well done on the MFI

[rhd racer]

Yes, well done. Excellent problem solving and determination

[knapmann]

Thanks for all the positive comments guys.

Continuing to tackle teething issues here.

1) Oil leak - I have a decent sized leak from the front of my engine (rear of car) I thought it was the distributor shaft so put some new O-rings on it and re-timed the engine. I seem to have fixed a leak here but I'm still getting a lot of oil. I think it has also been leaking from the crankshaft seal or - *pray to god not* - the No. 8 Bearing. Im going to have to take the pulley off etc to to investigate this. There is a lot of oil coming from here in any case. I also re-sealed a minor rocker cover leak.

2) Engine lid gas strut decided to die on me, makes everything more tiresome

3) Tested my idle mixture by disconnecting the mfi pump rod at idle and pushing it a tad to richen up the mix, the revs didnt rise which tells me that the mixture is not lean (could be rich but seems to be running fine)

4) My MFI fuel cut off has stopped working for some reason, it was working before. I did a lot of testing today on the solenoid, the micro-switch and the speed switch. The speed switch has failed, I opened it up and 2x transistor legs have corroded and broken. The board will need the 4x transistors replacing, hopefully this will fix it along with the horrendous fuel consumption, but this might just be a an old 911 issue!

5) Twice I have lost the 4th/5th shift plane. Try as I might I could only get 2nd/3rd gear. Not good when you are high in the revs going for 4th and you get 2nd! The grub screw into the gearbox selector shaft has been loose both times... not sure what is going one here as I have tightened it and tie-wired it in place both times. Im not a big fan of the aluminium selector joint. I think the grub screw thread is just dying to strip out... seems like a weak (shite) design to me. Should have a pin fitment straight through the selector shaft with a circlip on the other side like what my '02 had, much better design.

6) Hoovered out and washed the car, had 4 months of garage filth all over it since I rubbed down and polished all the paint.

7) Gearbox - plans are afoot for the 1st gear crunching issue...

8.) Installed a hidden mini bluetooth/auxillary amplifier. Screwed it to the underside of my glovebox so cannot be seen. Plays all my music via my phone or from my ipod via bluetooth or via 3.5mm audio jack. Plus no loss of glovebox space!

[Jonny Hart]

Regarding the MFI cut out. You can get the CDI+ to perform the speed switch function. Programmable on and off RPM too!