Cam Or Crank Sensor ,,,,

1990tbirdsc

Registered User
i have a 1990 sc ,automatic ,,,, it sounds like its wayy off time when i crank it ...it will crank fine for a second then it gets hard and slows down ,,, i though i had a fuel problem but i did a pressire test on the fuel rail and im getting between 36 and 40psi soo its not the fuel pump ,.,.,, and im sure its not the injectors because it would still run,, but it would run like ~~~~~ ,,,i dont think its the crank sensor because when i crank the engine the upshift light goes off ,,,, also .. i put a new cam sensor in today ,,, and got the dis tested and its fine ,,,, soo i dont know wahts wrong ... i bought a crank sensor just for the hell of it because thats all i can think of .. so im going to try that tomarrow i guess ,,,, does anyone know if i have to remove the harmonice ballencer ..or anything ,, or can i just get in there with a wobble socket to take off the old crank sensor .???
 
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You can change the crank sensor without removing the dampener. You will have to (well I did anyways) remove the crank pulley (mark it's bolt hole orientation to the dampener since it's a pain to figure it out on your back holding it up) and the plastic shield. It's still a tight fit. However if your upshift light goes out during cranking I don't think it is your problem.

Has it ever run? Are/were you getting a check engine light? Did you use heat sink compound (NOT dielectric grease) under the DIS module when you reinstalled? Mike8675309 posted a thread a long time ago that lists a complete diagnostic procedure for a DIS no start condition. Do you have a known good DIS module to try out? I know your DIS module tested "good" in the store, but I don't always trust their tests.

Do you know if your crankshaft dampener wobbles when the engine runs?

When I bought my '93 it would start, but barely run. It ran so poorly that even moving it around in the driveway was difficult. It turned out to be the DIS module in my case.
 
I had an LX 3.8 that sounded way off time when cranking it. it ran horrible too, turns out it had nasty blown head gaskets. Lots of things can cause it. Has it ever run for you?
 
no the check engine light was not on ,,,, and yes it did run ,.,,,,its ran perfectly fine for a long time ,,, then it just died ...its not the head gaskets because their brand new
 
and im sure its not the injectors because it would still run,, but it would run like ~~~~~
Can you elaborate on this? What exactly happened when the car started running poorly? Was it fine one day and then the next day no good? Did it die while you were driving and it was hard to restart? Any info you can provide will help us try to pinpoint what is wrong.
 
Right now I have three codes in my computer with no check engine light. Its not a requirement for the light to come on to have a code stored. Its worth a look to see which ones you have in memory. :)
 
turns over hard

I just went though this with my 90 SC auto. On my car it turned out to be the cam sensor. ( easy to change) I had my DIS checked at Napa and had a new crank sensor last year. Make sure you use the heat sink grease under the DIS and check all your ele connections. I found a broken connector and check the battery too. Give me points and plugs any day:) If you don't know what points and plugs are its great to be Young:cool: :cool:
 
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I Found The Problem ...!!!

OK ,,,,, TODAY I FOUND THE PROBLEM ,,,,, i took off all the belts because im getting new ones ,,,, and to grabbed the underdrive pulley/ harmonic ballencer and it wiggled up and down A LOT !!!...... SO i thought i had a broken crank or something along the lines of a blown engine...BUTTT ... then i grabbed the thing and pulled and IT ALL JUST FELL OFF ......the harmonic ballencer and pulleys all still attached ...except the bolt the holds it all on in the middle broke off somewhere ,,,, and sheered the keyway ,,, sooo it threw it off time and thats why it wont start ....sooo im going to order a new bolt from ford i guess ,?? .... and try to get out the peice broken inside the shaft..which means i have to remover the radiator and all the craP... well its alot easier than a blown engine ,,,!.,,,but im going to put on the new crank sensor and get a new bolt and put it back together and im PRAYING the bird will fly ... . hopefully ford can get the bold quick ,,, because i miss hearing my supercharger scream ,,, thanks soo much for all of your help everyone ,,i would have never thought of this even happening ,,, bye
 
DONT USE YOUR OLD STUFF!!! you need a new harmonic balancer, and need to make sure all the old one is off of the crank. You can use a 96 Mustang 3.8 bolt. Search here for harmonic balancer, and you will find more than you can read in a week as its a common problem. If you want it rock solid, shell out the money for a BHJ steel balancer and zero balance your pulley to it, or buy a new balancer from ford that comes with a new pulley, but whatever you do, dont bolt that old balancer back to your engine:D
 
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