89' Carrera 3.2 Randomly will not Turn Over

[28tbsfan]

I have been having an issue where the car will not turn over. It does this randomly, but seems to happen more in warmer weather. This could be a sign but I don't drive it very often if its not 60 degrees. It is very hard to diagnosis because this only seems to happen when I have the vehicle and not a mechanic. I left it with my last mechanic for two weeks and he claimed he started it over 100x times successfully.

The day I drove it home, it wouldn't start again 10 minutes after i left the shop.

Here is what has been replaced to unsuccessfully address the issue:

Replace crankshaft and position sensor and bracket
New plugs, cap, i.e. tune up
New Starter
Replace DME relay and Fuel pump

The car did not have any issues for about a year (limited driving) with the replacement of the DME/fuel pump, but went back to doing the same thing this summer of not turning over.

Any advice given I have spent around $2,500 to address this issue and multiple reputable shops have had a look at this?
Any where in the west suburbs of Chicago you would recommend have a look at it?

[GH85Carrera]

If it still has the orignal Bosch starter, they are prone to heat soak issues. They work great when cold, but heat em up and they lock up. If you have not tried the high torque starter available on Pelican, do that. Also replace the ground strap if it is old.

The other possibility is the plastic starter switch behind the key. If it always starts when cold, it is likely the starter. If the car will start up with a push start, it is likely the starter.

[proporsche]

Hi..if you are saying it will not turn over..is that it will not crank and it does not start??
Or it cranks but not fire up?



ivan

[28tbsfan]

Originally Posted by GH85Carrera

If it still has the orignal Bosch starter, they are prone to heat soak issues. They work great when cold, but heat em up and they lock up. If you have not tried the high torque starter available on Pelican, do that. Also replace the ground strap if it is old.

The other possibility is the plastic starter switch behind the key. If it always starts when cold, it is likely the starter. If the car will start up with a push start, it is likely the starter.

I just replaced the starter. Didn’t help

[28tbsfan]

Originally Posted by proporsche

Hi..if you are saying it will not turn over..is that it will not crank and it does not start??
Or it cranks but not fire up?

It cranks but won’t turn over and start up. It does this randomly.

ivan

It cranks but will not turn over and start.

[proporsche]

ok, it is turning over and it does not fire up....so..first do you have any alarm on your 911?
Second, who replaced the speed sensor?
3rd...Is it adjusted correctly?
4th..have you replaced the cylinder head temperature sensor?

Ivan

[28tbsfan]

Originally Posted by proporsche

ok, it is turning over and it does not fire up....so..first do you have any alarm on your 911?
Second, who replaced the speed sensor?
3rd...Is it adjusted correctly?
4th..have you replaced the cylinder head temperature sensor?

Ivan

I have the stock alarm. I do have a Steve Wong chip. Don’t think I had the cylinder head temp sensor changed

[proporsche]

The Steve`s chip is no problem..Too bad your mechanic(if he is 911 specialist) did not start with the temp sensor.


That should be your next thing to do...

Ivan

Also if it is stock alarm..not the problem, most likely.

[28tbsfan]

Thanks Ivan - wouldn’t this really only affect the running of the vehicle, not the start up.

[proporsche]

nope ...wise versa.....

[28tbsfan]

Originally Posted by proporsche

nope ...wise versa.....

Looks to be a $300 repair at a shop?

[old man neri]

Does it ever die on you while driving, even momentarily?

When you are cranking it and it is not firing up is the tach moving at all? It should be moving a little, almost vibrating.


There is a way to test the CHT using a multimeter.

I feel your pain, intermittent electrical/sensor problems are some of the most aggravating things out there.

[28tbsfan]

No, almost always happens after starting up then I park it, try to start it 10-15 min later and it doesn’t start. If I let it sit for an hour or two, it normally starts again.

[proporsche]

here is a test you can do..But first have a look if you have the white connector with one or two prongs.If one it is the older version and a sign it has to be replaced anyway.
the sensor is about 80 bucks ..
here

[old man neri]

I agree with the above statement.

[28tbsfan]

Originally Posted by proporsche

nope ...wise versa.....

Ivan - my mechanic is telling me the 1989 911 model cylinder temp sensor does have a direct effect on starting the vehicle. He agreed in theory, if the car was started and then sitting and restarting hot, this makes sense but not if the car wasn't starting from not running (cold).

Thoughts?

[rokemester]

Originally Posted by GH85Carrera

If it still has the orignal Bosch starter, they are prone to heat soak issues. They work great when cold, but heat em up and they lock up. If you have not tried the high torque starter available on Pelican, do that. Also replace the ground strap if it is old.

The other possibility is the plastic starter switch behind the key. If it always starts when cold, it is likely the starter. If the car will start up with a push start, it is likely the starter.

You won’t be push starting a 911 with electronic fuel injection. I’m so used to push starting my 66 Bug. I left my parking lights on last summer and the battery was dead. Not thinking I tried push starting my 87 3.2 a couple of times before it occurred to me it would never start that way! Old school analog mechanical fuel pump and carburetor can have its advantages😉

[steely]

Originally Posted by 28tbsfan

Ivan - my mechanic is telling me the 1989 911 model cylinder temp sensor does have a direct effect on starting the vehicle. He agreed in theory, if the car was started and then sitting and restarting hot, this makes sense but not if the car wasn't starting from not running (cold).

Thoughts?

Some will not start with a bad CHT.

My suggestion would be to disconnect it and try for yourself and/or at least do the test Ivan suggested (some time ago), come back with the results, and then ask for thoughts.