92 SC AOD tachometer drops to zero

jeffleeismyhero

Registered User
I have been having some trouble with by car recently. While driving, the tachometer will drop to zero (as if it stops working) and then randomly bounce back (sometimes minutes later). In addition to the tac, the check engine light will sometimes come on (other gauges are fine).

When the issues above occur, if I shut off the car it will not start. It acts like it is going to and doesn't. Today, for the first time, the car semi-died on me. It wouldn't accelerate (check engine light had come on, tachometer unresponsive). I pulled over, shut it off and tried starting it again. The car behaved the same way I mentioned above and I notices white smoke blow by.

After waiting a few minutes (10 or so) the car started as if nothing had happened. I was able to drive around for about an hour to finish what I was doing (starting and stopping the car numerous times) and the car acted normally.

Although I have already ordered a new car, I would like to keep this one. I don't want to continue pumping a bunch of money (hahaha right) into it but I would like to sort this out. I am on my 5th tranny, 4 from one shop under warranty and 1 from a respectable place that seems to have gotten it right.

Triple A is well worth the money...
 
Do a search for symptoms of a bad DIS,for crazy tach and poor run.

If the white blow by, means white smoke from the tail pipes
White smoke will be found by looking at symptoms of a blown head gasket
 
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I don't think it is a blown head gasket b/c it only occurs when this problem is present.

Do you know where I can get the DIS module? Auto Zone want 125$ for it. I saw a thread on here trading one for around 25$ a while back...
 
Could be a few things.

I'd start by checking to see if it is the cam sensor. You can test this by just disconnecting the thing and driving the car. It'll be a little hard to start when it is disconnected. But it should run fine. If you still have the problems with the cam sensor disconnected, then it's something else.

If the problem goes away, then you have a bad cam sensor.

A bad DIS can cause what you describe as well, but it isn't as easy to trouble shoot.
 
Yeah, but....

I had the same problem, but it wasn't the cam sensor which is what it usually IS.

My waterpump went out and I overheated. Then, there's a bare ground wire lead in the harness from the cam sensor, (for noise suppession), which melted into the insulation of the tach signal wire, intermittantly shorting it. :eek:

That was a lot o' fun to find! :p

Lee
 
My bro's 93 started doing that in the summer. When it ran like that, it had very little power. Shutting it off and restarting usually resulted in normal operation.

I changed a bunch of stuff on it a few weeks later and the hg's blew. It was behaving like the above symptoms right before they went. Could be a coincidence but I did notice a little white smoke from the tailpipes in the weeks before when it acted up.
 
Also do not be surprised if it takes a few tries to get a good cam position sensor. I am swapping out what I think is my 4th one tomorrow.
 
Four tries, must be used sensors but still not a good track record. Why not just go with a new one?
 
4 brand new Borg Warner sensors. If this one does not work I may look at replacing the syncronizer as it does not look so pretty underneath, unlike some pictures posted on this site. I may also try a actual Ford one if I have to.
 
Wow, new sensors crapping out like that. Doesn't seem likely that it is just the sensors.
 
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