Cylinders dropping out

tamperproof35

Registered User
I been having a problem with my 91 SC, when it is cold it has a rough idle,warms up fine.Today I was drive home and it seems like half the cylinders stop fireing,and the tach reading was all wrong,Is it the dis module? or something else.? thanks
 
90% chance that its the DIS module. I JUST went through the same thing.. I was running 4 of 6. If you pull codes, I'll bet you get a coil related code.. go ahead and check the coil pack with an Ohm meter, but chances are its good. The DIS is usually the culprit. When this happened, bet your tach reading actually dropped, didn't it?
 
Usually..

this indicates a bad Camshaft position sensor. Easy to change and cheap to buy. I'm sure a quick search of bbs would yield you the procedure.

Darryl
 
Tach dropped,I guess it's the module.I removed it and cleaned it,put on some new thermal compound and tryed to start the car,missed it first then cleared up.Think that repaired it or am I going to be walking one morning.
 
Don't think you'll be walking, but you could be stumbling. Cleaning the base probably won't fix you up for good. The DIS is electronic and once it overheats and start acting flakey, internal circuits may be weakened. But, it usually doesn't drop all 6 cylinders, so you may be able to limp home.

3 related things every SC owner NEEDS to know:

1. If the uparrow on the tach lites up and stays lit when trying to start the car... it means the EEC is getting no signal from the crank sensor. Crank sensor is always a no-start or shut-off. Keep a watchful eye on it.
2. Cam sensor failure is often accompanied by long crank times, a wavery or dead tach, and extreme bucking and is intermittent. If the cam sensor goes, you can still start the car, and each time you have about a 30% chance of it running. try try again but key off first.
3. The DIS generates codes, the cam and crank sensors do not always generate direct codes..

Hope this helps.
 
DIS

it seems like it could be the DIS module...i had the same problem with mine. you can pick one up from advance auto parts, NAPA, etc...dont buy it from the stealership....when you buy it from the auto parts stores, dont worry if it doesnt say motorcraft. i took my old DIS off, cleaned the base, added some thermal stuff, plugged the DIS in and it solved the problem right there. i havent had a problem with it since and its been about 6 months now. hopefully this helps...
 
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