Is culprit the cam sensor?

joenintiesc

Registered User
Ok, I just finished a bunch of stuff to my 90SC: motor mounts, ported exhaust maifolds, hi flow cats, new O2 sensors, 190 fuel pump, 42# injectors, 75mm tb, 76mm C&L maf, new tuner file from Dr. Fred. Also have a MPII blower, plenum, and top.

From what I already know and searching the forum I believe my current problem is related to the cam sensor. I am having a hard start problem with no tach (sometimes). But once it's running, it idles and drives fine. Wouldn't a bad cam sensor also cause driveability problems, like bucking? Also, sometimes the tach is working and it starts right up. Would this be a wiring/connection problem that could possibly be corrected without replacing the sensor? Sometimes if I jiggle the wires/sensors I can get the tach up again...

On the other hand, I had to drive 60 or so miles without the 76maf, and it was running very rich. Could it be a fouled spark plug causing hard starts - probably not becuase of the sometimes dead tach, right?

Also, I've gotten some KOER codes and they are as follows:

42 No exhaust gas oxygen switching detected- always indicating rich

92 Exhaust gas oxygen shows rich bank 2 or fuel control circuit failure

53 TPS voltage is too high

Also, got this memory code:

19 Cylinder identification failure

Is it possible I have a bad o2 sensor? Any help would be great!

Thanks guys, you rule! :D
 
It's the cam sensor, what happens when it goes bad is the computer goes into a random trial and error to find the correct cylinders to fire on, usually gets it the third try. So once the computer figures out which cylinders to fire it will run fine, to some extent. Could be wires I guess, check and see if you have any fraying at the plug. Sensor is easy to change so don't sweat it if you have to, part is cheap too, less than $20.
 
Thanks Aaron, I notice you often come through with the first response and I appreciate it!

Now I wonder if those other codes I'm getting are related - somehow I don't think so. I'll see what happens after I replace the cam sensor...
 
No, prob. I sit in front of a computer all day so whenever something new comes along I try to help. I was once clueless about this car but after having it for 8 years I have banged my head up against a wall countless times and figure I should help others avoid the bruising if I can. Usually all the stuff I respond to I have been through. I would change sensor and reset computer and then check for codes again.
 
mine was doing the same thing, sometimes it would start right up and sometimes it had to crank forever. once , when it did start it idled for a while then died, and once the tach acted wierd. but most of the time once it started it ran fine. My shop manual explaind that if the DIS is not getting a cylinder ID signal from the cam sensor , the computer will try to fire random cylinders untill it finds the correct one, so that's why the long crank time sometimes. Anyway the cam sensor fixed my problem, it starts right up everytime now.
 
I have a weird feeling that it may not be the sensor itself, but the wiring/connectors somewhere in there... When we did all the work we moved all of those wiring harnesses every which way and now I wonder if something was damaged or brittle and didn't like being moved... It worked fine before and is now intermittent. I'll start cleaning some of those connectors when I get home tonight and going over them...
 
Hey Aaron and Kevenj90SC,

Did you folks buy the cam sensor from the Ford dealer or local auto parts store. I'm just now having this problem, thought I scan the threads and came across your conversation. Any assistance is greatly appreciated.

Thanks
Greg
 
Thanks for the info. Sorry to ask another favor, but do you have a part number. I have an '89 SC manual if that helps.

Thanks agian for your time.

Greg
 
Aaron,

Don't know if you have shopped for a Cam Sensor in So Cal yet, but every dealer they checked on for me had them listed for around 60 bucks. Its locality I guess. Talking to Kurt Sr, when my crank snapped and I needed a Harmonic Balancer, he said he bought one from Ford new for about 150 and I got mine for about 100 more :( Damn, Southern Cali inflation I tell you.

Al
 
Mine cost $40 in NJ. Then I got home and found out I didn't need it after all! (Unplugged the existing one, sprayed in some contact cleaner, and wa-la good as new... :D ) I guess it's not a bad idea to keep a spare in the car considering they do go bad and it's such an easy repair...
 
cam sensor is Echlin # CSS405 from NAPA. Echlin is an OEM supplier to Ford, in fact in the exact where the ford part number is on the original one, the new one had that area scuffed up, even though it was brand new....obviously to remove the Ford part number. It's the same part, don't need to go to ford.
 
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