Bertrand Daoust

Like John said, don't pry it with a screw driver! I did and broke it flush!!!
Here is what I did to remove it.
Ok here we go!
I did remove it from the top.
By the way, you can't easily reach it from under as the flywheel is the way!!!
Also, don't try to push it out from under as you will probably bent it and have more problem removing it from the the top. Ask me how I know!

Anyway here's how I did it.
1) I put alot of penetring oil on top of the CPS.
2) from the top, I used a Dremel tool to remove as mutch plastic as I can inside the CPS on top and around the magnet. About 1/4" below the top of the magnet worked fine for me.
3) I used a pair of long nose plier and pull the magnet out. It did come out quite easily.
4) Now that the magnet is out, you can tap the hole and use a long bolt, nut and a spacer (a 1/2" small pipe work well for me) and take it out!

When I pull the CPS out, the lower metal part separated from the top plastic section and stayed stuck inside. Now another problem. As I could't remove it from the top, I push it from the top and picked it from under on the top of the bell housing.

It took me about 5 hours to do it but at least I did not have to remove it from under - moving the trans./ torque tube, removing the flywheel etc.

Just take your time and try to remove it without braking it!

Good luck.

Hilton

Are you sure the sensor is duff, and not just the harness connection? It might be easier to just wire up a new connection.

Being a manual, its not so hard to get at it from underneath. Dropping the clutch pack and removing the flywheel is only an hour or so, two if you've not been in there before. So as a last resort its probably easier than picking the bits out from above.

As far as penetrating oil. I recommend you grab some Liqui-Moly ceramic freeze spray. Here's a link: http://www.liquimoly.co.uk/index.php..._details&id=22 - it's much more effective than WD-40.. there are as mentioned by others above, alternatives, but I'm not sure which are available in the UK. They also make a more general penetrant but I can't see it on their website (we get them here in oz)

Take the MAF out, move the vacuum line from the booster to the intake forwards so you can get under/behind it, and use a punch to tap on the head with a hammer.

Then spray it copiously and wait for it to penetrate. Tap again for good measure, then try undoing the bolt again.. if the head shears off, then you can have a go at getting the sensor out. The sensor itself will be stuck in with crud from clutch discs, grit, oil, and probably corrosion too. Lots of penetrating oil, and then try wiggling it a little, rinse and repeat until you get bored, or it comes out.

If its stuck firm, I'd go in from underneath, where you can clean the crud and grit off and use heat without burning fuel lines. Then try pulling from above again, and after that, tap it up with a dowel and hammer.

If you do end up going in from underneath, also take the opportunity to replace the clutch ball-cup bushing from the release arm - odds are its toast and you'll have the arm out anyway.

John Speake

As you're in the UK, use Plus Gas as a release agent.... suggest you edit your signature to give loaction and your car details.

Welcome to Rennlist ! Do become a paid up member, it will be the best investment you will ever make for your car.

Bill Ball

I love this kind of "Oh, S#$&!" incident report.

There was a guy who asked me to replace what I found to be a perfectly intact crank sensor as part of a general refurb. I got the bolt out but the sensor wouldn't budge with a variety of tools. When I got to the screwdriver, I stopped. He probably wasn't real thrilled when I told him his old sensor was fine and he should wait to replace it when the motor or trans was out for some other reason. Your account was exactly what I was invisioning.

Congrats on toughing through it.

928GTSM

Hi John, I assume I'm a paid up member as I paid through paypal when I joined, I didn't want to disturb another of your weekends with my problem hence why I posted on here. Sadly the connector wasn't as easy to get to on my GTS as you thought it was, either that or I'm even more useless than I thought I was!
A quick update is that I removed the fuel pressure regulators & hose that go across the back of the engine. I bought a ratchet drive allen key set and the bolt came out quite easily once I could get on it properly. The sensor as suspected is not proving quite so easy, to the point that in trying to get it out I slipped and somehow managed to trap my right middle finger as I fell forward and snapped a tendon in it!!! Would you believe 8 - 12 weeks with it in a splint and they say it may never heal.
I hope it is this sensor that's the problem , what is the Temp II snesor that I've seen reference to, is this also a possibility for causing my enging to cut and not start once it's up to operating temperature?

Hilton

Ouch! Sucks about the finger.. lucky it wasn't an index finger, as that'd have stopped you turning spanners

Temp II is at the front end of the intake on top of the coolant bridge - right-side of the car. However it's unlikely to cause your engine to actually die - usually failure just results in very rich running and hunting idle.

Its easy to test tho - pull the Bosch connector off (its blue I think on a GTS? think they used blue for that one from 89-95?), and test each pin to ground to make sure its not open-circuit (its actually two sensors in one - feed is taken from each pin to the LH and EZ-K respectively).

More usually, CPS failure is actually CPS-connector failure where it plugs into the harness (just underneath the plastic throttle wheel). Its a 3-pin Bosch connector and the sensor-side crumbles and falls apart. The intermittent nature of your problem says its likely just an electrical connection rather than the sensor itself, so you may not need to remove it.

928GTSM

Hilton sadly there's nothing intermittent about it, once it get's up to operating temperature the engine dies and won't restart again until it cools down. It then runs fine again right up to the same point and bingo.

Hilton

The CPS sensor (if its at fault) must be intermittent.. your car wouldn't start at all if the sensor was failed, as there'd be no spark. The CPS signal tells the EZK the engine is turning, and EZK initiates spark. Without a CPS signal, you'ld have no spark at all, consistently.

An intermittent CPS failure wouldn't be so reliable in its symptoms usually, although some have reported it causing a hot-start problem as the block expands slightly and can open the circuit if the connector has failed.

Any other symptoms when its failing to start? Injectors clicking with the ignition in the on position? When you try to restart it, does it turn over ok, or does it crank very slowly (or not at all?) with the starter motor?

Its very unlikely, but the symptom sounds like Thrust Bearing Failure, which is most commonly a problem for late Auto's, but is possible on manual cars too. Have you checked the oil for metal particles, or measured crank end-play? Dripping oil from the dipstick onto some black paper or card after the engine's been running for a minute is a good indication.

Lizard928

I would verify that the sensors signal is cutting out.

Though they do need to be replaced after awhile.

I have never had one break on me. I turn them back and forth while I slowly lift with my fingers they always come.
There is an o-ring on the sensor and the build up or dirt/corrosion is what prevents it's removal. The wiggling back and forth slowly works through it.

When installing a new one ensure to coat it with the silver never/anti sieze so as to prevent a build up if it is needed to be removed later.

928GTSM

Hilton, when it cuts out initially for the first few revolutions it is quite lazy but then cranks over as normal. At this point however there is no spark at the plugs and the fuel pump does not run. I've tried swapping the relay and I've wired the pump direct to a 12 volt battery and it runs fine, you can hear the fuel coming back to the tank. There is no fluctuation at all on the rev counter needle when cranking the engine which I'm told is also a sign of possible CPS failure?
Lizard, thanks for the tip, the sensor will rotate a small amount and I'm taking it very slowly putting plenty of penetrating oil on it and being patient, mainly because I now can't grip the thing properly anyway!

blandis

You can also drive a torks bit in the allen head if it strips out. I would try heat first as Greg suggested.

Hilton

Ok that's more reassuring that it cranks over fine when hot.

Agree that it sounds like the CPS is at fault as you've tested spark and fuel pump - so taking it out is definitely a good move.

I repaired the harness and sensor wiring on one of my 928's, but the car was running fine with no issues, so I knew the sensor itself was still good (I had the intake off for intake refresh so access was good).

John Speake

I've known several CPS to only fail when engine is hot. This car is a 5 speed...

928GTSM

Well after some considerable effort I finally managed to disconnect the lead on the CPS but with my middle finger in a splint I can't grip the sensor tightly enough to twist and pull at the same time. It moves round as much as the adjacent bracket will allow but I can't get under the bolt end to pull it evenly and I don't want to bend it. I'm assuming that what is actually stopping it coming out is the rubber O ring. I keep applying penetrating oil but so far to no avail.
I was thinking of trying to find a self tapping bolt or such like of the right size to screw into the brass bush that the bolt came out of so I could pull up on both ends at the same time. I also considered trying to get a small set of mole grips which would be big enough for me to be able to grip properly. Would I be right in thinking that this may only end up with the plastic top section getting crushed?
I've been warned by a couple of people not to prise it up with a screw driver or such like so I'm open to suggestions.

fraggle

I tied a bunch of safety wire around mine and was able to tug it out. It was challenging. But it did put all the force in the "right" direction (up) so it didn't break off. I did have to remove the fuel lines.

Then I found the harness was worn through about 3" away from it. The sensor itself was fine, but was destroyed during the disassembly process.

The only way to really test the thing properly is with an o-scope.