cam sensor or crank sensor??

kennster

Registered User
I sometimes have trouble starting my 92 SC when the
engine is hot...now on the highway the tach started to
twitch and then the engine started puttering..and backfiring
,,and the tach was going nuts...i finally got it going and
drove it home...just wondering..is it the cam or crank sensor
that may be doing this???or is it something worse??thanks in
advance guys...
 
A screwed up tach can be the cam sensor or a tempermental DIS that is getting heat sensitive. First thing to try, hit Radio Shack and pick up a tube of heat sink compound. Remove your DIS, clean the old stuff off and put on a thin layer of the heat sink compound and reinstall it. See if this helps, if not try the CAM sensor it's easy to change and not very expensive.
 
...Sounds a lot like Steve Richards' current problems. I think he's working on grabbing a used DIS to try, but perhaps he should try the heatsink compound first too!

Steve???

Cheers,

Sean
 
That's possible, I guess. It is awfully coincidental that his problems started just after doing the engine shampoo.
 
I've heard many stories about electrical problems, most on other cars, directly after using those heavy duty de-greasers.

I say the DIS is #1.

BTW, I have a strong suspicion that Steve may need a crank sensor. That would explain the tach being off and the constant fluctuation in RPM. Also, why it runs great, then ruff intermitantly.

Whatta ya think?
 
From what I've read on these forums, the crank sensor either works or it doesn't. I suspect that if Steve's crank sensor was toast, then the car just wouldn't run. I'm not sure why Steve's tach is off, but I presume it receives signal from the crank sensor, so maybe you're right and there's a problem with the crank sensor. Maybe the sensor became loose and the gap is incorrect between the sensor ring and the sensor itself? It's kind of ugly to get at to check!

Cheers,

Sean
 
cam sensor

I would say its the cam sensor because the dead give away is the tach going crazy and the car is running,bucking and hard to start when hot. However the cam sensor may not always be the case ther could possibly be something else going on like the crank sensor or the DIS. But before you do any thing else or change the cam sensor perform this simple test: unplug the cam sensor, keeping the connector away from the charger belt. Next, crank the engine. It may start on the first try, if not you'll have 3-4 attempts before it starts. If it fails to start the plug the cam sensor back in and replace the crank sensor. Reason being that when the cam sensor is unplugged the EEC compensates for the CID thereby allowing the EEC to guess which cyl to fire. If the EEC guesses right the first time it will start on the first try, That is why I said earlier 3-4 attempts for the EEC to guess right or compensate for a healthy cam sensor. Additionally with the cam sensor unplugged the car will run without bucking but will have a slightly rough idle until you replace the sensor. The car will/should start or re-start/run even when hot or if it has been running for a while. A word of caution should you need to replace the cam sensor: make sure you set the new sensor in correctly, that is with a special tool or you can adjust it with a scanner once installed for 100% accuracy----26 degrees ATDC on compression stroke. Good Luck!







kennster said:
I sometimes have trouble starting my 92 SC when the
engine is hot...now on the highway the tach started to
twitch and then the engine started puttering..and backfiring
,,and the tach was going nuts...i finally got it going and
drove it home...just wondering..is it the cam or crank sensor
that may be doing this???or is it something worse??thanks in
advance guys...
 
wow.....

wow fordrunner.....digging through the archives???this thread is about a year old.....hahaha.....thanks for the advise..it was the cam sensor.......peace!!!!
 
i had the same problem for the longest time....what i would try first is put some heat trnasfer compound under the dis...i did this and i haven't had a problem since
 
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