1990 Festiva crankshaft position sensor

[1990Festival]

So my 1990 festy died on me in the middle of the road shortly after running very rough and throwing a CEL. Had to have it towed home. The CEL is 02 for crankshaft position sensor. I have searched everywhere for a place that will sell just the sensor but I have been unsuccessful. Do I have to buy a whole new distributor or is it possible to just swap the sensor. If so does anyone know where I could find it? TIA.

[TominMO]

Rock Auto does not list one for a Festiva, which does not surprise me. I don't recall ever seeing one on my car. There is one listed for Aspires though. Do you by any chance mean a throttle position sensor? Those are available separately.

A code 02 on an EFI Festiva does not indicate a CP sensor. It means "IDM" (whatever that means).
I found this page which explains it. Read the notes below the chart.

[1990new]

Be sure to rule out all the other possibilities before you buy any parts.
How long has it been running rought? Have you had the timing belt off recently? Did you remove the lower timing gear?
Could even be an electrical connection issue, or worse, a crankshaft keyway wallow out.
If you have the optical sensor in the distributor, it could just be dirt issue (Sometime the seal fails in the distributor shaft and lets oil get in there and coat the sensor lens). What's the number on the side of your distributor? If in the end the cam position sensor has failed in the distributor and I have a distributor like your (I have several), I will let you have it at a reasonable price. However, I don't think that part fails very often. I'm not the expert on this here, other folks will jump in to give you more opinions soon too.

Like Tom says.. there is no actual crank position sensor on the Festivas. I just assumed you meant cam.

[TominMO]

OK, went out to the garage and got my Haynes manual. It does list code 02 as crankshaft position (CP) sensor, for 1990 - 1993--BUT it lists the corrective action as "Check the distributor CP sensor and circuit". So it is in the disty, and calling it "crankshaft position sensor" is misleading, since the disty is connected to the camshaft. Hope this clears it up a bit for you.

You need to get a Haynes manual; saves a lot of trouble, like this one.

[1990new]

Another thing that can cause these symptoms is the Ignition Control Module.
It is located on the strut tower near the ignition coil. First thing to do is remove it
and clean all the connections and see if the car will start after you do.

That is really confusing naming it the Crank Position sensor when it's really the cam. If the timing belt is off or the crank sprocket is off it really only tell you the position of the CAM. But then in reality it is supposed to tell you where the pistons are to know when to fire the plug and that is determined by the crank position. I found this that might help you test it:

Actually on this application the crankshaft position sensor is located inside the distributor. It isn't servicable alone.

Access the connector at the distributor for the Crankshaft Position (CKP) sensor.
Check the Yellow/Black (Y/BK) wire for battery voltage. Check the Black (BK) wire for a good ground. When cranking the engine, check for a 0-5v square wave on the Yellow/Blue (Y/BL) wire using a lab scope or graphing meter. If a lab scope is not available, monitor the voltage on the Y/BL wire with a voltmeter while bumping the engine over. The voltage should switch from 0v to 5v as the distributor turns. If this does not happen, suspect a faulty CKP sensor in the distributor.
Also, Try unplugging the vane air flow meter and recheck.

[Greywolf]

I have often found that a visual inspection can reveal the obvious before I jump off the deep end.

What this sounds like to me is a timing belt, honestly. It's one of the obvious things that DO wear out over time (no pun intended) and that are easy to replace.

I'd have a look at that first, especially if it has never been changed since you got the car.


This is also the reason why most people throw away the timing belt covers, so they can see the belt and what condition it's in.


RATIONALE:
1) A worn or jumped timing belt will throw off the mechanical timing of the entire engine, and cause a CPS call out from the fault logic.
2) A worn or jumped timing belt will also cause rough running, before it skips again
3) I have found the electronics on many of these types of cars to be as bullet-proof as you could ask for.
4) Anything made out of rubber will wear out eventually, belts are predictable and considered a scheduled maintenance item


Even if the T-Belt is not the cause, at this point it should be replaced just on general principles, ask yourself this:
Do you REALLY know how old it is?

[TominMO]

Another thing that can cause these symptoms is the Ignition Control Module.
It is located on the strut tower near the ignition coil. First thing to do is remove it
and clean all the connections and see if the car will start after you do.

+1. This should be checked out. Corrosion can build up inside the coil wire connection, so remove the wire and look for corrosion in there. People replace disty caps and rotors, but the coil never gets replaced on a regular basis. You can clean it out with a piece of rolled-up sandpaper, not too gritty. The coil piece is pretty cheap on Rock Auto, and free at the JY. If you click on the part# at Rock Auto, you can see what other cars use it too.

I had a similar experience to yours in the first post--but I just happened to have william with me, who found the problem. And I just happened to have a spare coil too, and tools. So on the road again in 15 minutes or so.

[1990Festival]

I checked the connections to the ignition control module and everything looks fine there, no corrosion or debris. I ran the voltage check on the CKP. Ground is good and when I crank it over it has a constant 5v, does not switch from 0-5. I have never removed the timing belt and I have no idea if it's ever been replaced. Would a bad timing belt cause it to throw a code for the CKP sensor? I guess I'll start there since it is cheeper than changing the distributor. I will also post the number located on it when I get a chance. Thanks to everyone for the help.

[1990Festival]

I will get a look at the timing belt when I have a chance to get to it.

[1990new]

I checked the connections to the ignition control module and everything looks fine there, no corrosion or debris. I ran the voltage check on the CKP. Ground is good and when I crank it over it has a constant 5v, does not switch from 0-5. I have never removed the timing belt and I have no idea if it's ever been replaced. Would a bad timing belt cause it to throw a code for the CKP sensor? I guess I'll start there since it is cheeper than changing the distributor. I will also post the number located on it when I get a chance. Thanks to everyone for the help.

The voltage should switch from 0v to 5v as the distributor turns. If this does not happen, suspect a faulty CKP sensor in the distributor. Sounds like you are narrowing it down.

[FestYboy]

You won't see it switch while cranking and using a DVOM, they're too slow to read the signal. You need to do it by hand by pulling the dizzy out. While you're in there, check that the CPS isn't covered in oil... That can cause a no switch symptom.

[Greywolf]

Unless the cam belt has broken completely or got stripped clean - the voltage you checked should at least "Change State" from 5 to zero, so it sounds like the sensor was a better answer than mine.

Me personally though, a cam belt is on the list for the B6T car I recently acquired even though the previous owner ditched the belt covers long ago and I can see that it looks in decent shape. If it was an automatic I'd add a starter motor to that list just to make it fail-safe

"Trust not what was done before thee, for tow truck drivers ravage the unprepared..."