tdc sensor set up on 944S2
Discussion
Hello all help needed change the clutch on my S2 and now engine wont run for more than few minutes (ie when warm) was told it could be tdc sensor so changed that, had to take of bracket to get old one out and I think this is were the problem may lie. I belive there is a setting when intsalling the tdc/ bracket back in and wonder if any one has had same probs. By the way the clutch went in fine. just will not run now after getting warm. Any advice gladly taken Tony.
Hello
So you have done the clutch and now the engine will not run when warm...
When you say wont run when warm...do you mean it warms up then stalls and will not restart or gets warm,stalls and then will restart then stalls and so on....
Have you checked to see if you have dislodged any of the intake air system piping so when it comes off cold start it runs too lean and cuts out as you have big air leak ? (only a suggestion) as you have to drop bell housing someway to get it off if i remember correctly.
Mike
sportsandclassic
So you have done the clutch and now the engine will not run when warm...
When you say wont run when warm...do you mean it warms up then stalls and will not restart or gets warm,stalls and then will restart then stalls and so on....
Have you checked to see if you have dislodged any of the intake air system piping so when it comes off cold start it runs too lean and cuts out as you have big air leak ? (only a suggestion) as you have to drop bell housing someway to get it off if i remember correctly.
Mike
sportsandclassic
we made a spacer many years ago to set the clearance between the bottom of the pick up and the flywheel - I seem to remember it to be 0.8mm - but that would certainly run OK.
They are difficult to remove and you can damage the windings and reduce the number of coils that are engaged - so reducing the signal strength. When re-assembled they must not be too tight in the hole.
You will have noticed that one of the 2 allen bolts that hold the bracket in - is to adjust it (the bracket has a slot) and the other just tightens it on a dowel for it to rotate around.
Just take it out again and either make up a spacer tube or measure down from the top of the bracket and compare to the length of the pick up.
One final thought - are you sure you replaced and fully tightened the earth strap?
Baz Hartech
They are difficult to remove and you can damage the windings and reduce the number of coils that are engaged - so reducing the signal strength. When re-assembled they must not be too tight in the hole.
You will have noticed that one of the 2 allen bolts that hold the bracket in - is to adjust it (the bracket has a slot) and the other just tightens it on a dowel for it to rotate around.
Just take it out again and either make up a spacer tube or measure down from the top of the bracket and compare to the length of the pick up.
One final thought - are you sure you replaced and fully tightened the earth strap?
Baz Hartech
Baz - surely it would need a signal from the TDC sensor to start up? Therefore, if it starts and runs at all, the TDC sensor must be OK?
If this locig is correct, I'd be looking for something else wrong. Air pipes is a good one, fuel pipes another.
It's something that changes as temperature increases, so could be something electrical. How about a connector on a temperature sensor?
Oli.
If this locig is correct, I'd be looking for something else wrong. Air pipes is a good one, fuel pipes another.
It's something that changes as temperature increases, so could be something electrical. How about a connector on a temperature sensor?
Oli.
Hi olli - you will find that if the sensor has been pushed in until it almost touches or just touches the flywheel, then they will often start up but as the oil thins and the crankshaft run out slightly increases - the pick up touches the flywheel and this stops the signal timing from being applied correctly. We have - over the years - seen this a few times as customers push it in uinjtil it stops - not realising about the clearnace needed.
On older flywheels with the allen screw trigger - we have seen this knocked off all together by a pick up being pushed too far to touch the flywheel or with the right clearance - except to the flywheel not the pin.
Also (but not applicable in this case as the sensor was new) - we have found sensors corroding to become tight and when the heat expands them the windings short out and reduce the signal. Then sometimes because new ones are tight to fit, people twist them around to get them in the hole - not realising that the stainelss steel outer sleeve is stuck and they are actually twisting the plastic at the top round and screwing the windings back and forth inside the pick up causing a break down of contact when the shellac on the coil windings rubs against itself - reducing signal strength.
This is often the problem with giving advice. There are probably at least 20 things to check in this scenario (as described) and you are never sure what else may or may not have been done wrong, checked or not checked - so it is often better to start with the most common answers to try and help.
However - more often than not we find - just as the owner did - that it is something else entirely that causes the problem and this is why it can take a long time to diagnose problems on an old car when it will not run but the customer has changed something that he is sure can be the only cause.
Baz Hartech
On older flywheels with the allen screw trigger - we have seen this knocked off all together by a pick up being pushed too far to touch the flywheel or with the right clearance - except to the flywheel not the pin.
Also (but not applicable in this case as the sensor was new) - we have found sensors corroding to become tight and when the heat expands them the windings short out and reduce the signal. Then sometimes because new ones are tight to fit, people twist them around to get them in the hole - not realising that the stainelss steel outer sleeve is stuck and they are actually twisting the plastic at the top round and screwing the windings back and forth inside the pick up causing a break down of contact when the shellac on the coil windings rubs against itself - reducing signal strength.
This is often the problem with giving advice. There are probably at least 20 things to check in this scenario (as described) and you are never sure what else may or may not have been done wrong, checked or not checked - so it is often better to start with the most common answers to try and help.
However - more often than not we find - just as the owner did - that it is something else entirely that causes the problem and this is why it can take a long time to diagnose problems on an old car when it will not run but the customer has changed something that he is sure can be the only cause.
Baz Hartech
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