No Tachometer - Is it the CPS or CID?

[Cohiba]

While cruising around today, my SHO started acting kinda strange, bucking and appearing to lose power for a second or two whenever I touched the brakes. Then the tach started going nuts... jumping up to 9000+ and then dropping back down, then holding at the correct RPM... finally, the car died while at a stop light, and when I restarted it (started right away), there was NO reading on the tach. Nothing. The "bucking" and drivability issues appeared to go away at this point, and didn't return the rest of the drive, but the tach never came back.

So... my question... I'm thinking that this is probably a problem with either the crankshaft position sensor (CPS) or camshaft identification sensor (CID). Should I replace both, just to be safe, or is there a way to tell which on is at fault? Also, I have no idea where the CID is. ??? Anybody have a "how-to" for replacing it?

The CE light never came on, and I haven't checked for stored codes yet (I know the CID failure doesn't illuminate the CE light). I'll do this tomorrow. Does CPS failure cause a CE light?

 

[pete c]

maybe if you post this question a fourth time, you'll get an answer. Anyway, I'm a show newbie, and I really can't give you any kind of knowledgeable answer, but, here's one that's worth atleast as much as you are paying foe it!

Since it started bucking at the same time the tach acted up and then ran fine once the tach died completely, I would ges that the tach died. As it was dieing, it became a short circuit to whatever it is connected to, which is somewhere in your ignition system. In doing so, it gragged down the ignition with it, until it went completely **** up and released it's death grip on the rest of the system. This answer could be and probably is way off, but, if I had to make a guess, that would be it. If you have any schematics to the car, you can find out where the tach gets it's signal, plug another tach in (don't bother mounting it yet) and see if the signal is still there. If it is, replace the tach and hope all is well, if it is not there, talk to somebody else who actually has a clue!!!

pete

 

[Cohiba]

pete c:
maybe if you post this question a fourth time, you'll get an answer. Anyway, I'm a show newbie, and I really can't give you any kind of knowledgeable answer,

Sheeesh... obviously. It's called a SHO, not a "show"!

<strong>
talk to somebody else who actually has a clue!!!

pete

That is what I was hoping for....

 

[nc89sho]

the tach getts it's info from the CPS. if the car is acting up and the tach is not working, that is usually the culprit. sometimes it goes out all at once, (car on the side of the road) or sometimes it hangs on for a while and causes problems (stalling intermittently, bucking, dead tach ect.) hope that helps.

 

[luigisho]

The CID is in the rear of the engine compartment passenger side. To the rear left of the intake. It's black and semicircular near the strut tower. Kind of a tight fit in there to get tools on it. Sounds like crank sensor to me.

 

[SHOfun 93]

Sounds exactly like when my CID went out. Then it bucks really hard when you try to restart after shutoff..

 

[Cohiba]

The day it went out, the car was acting up, bucking, and losing power when I applied the brakes. Then the tach started fluctuating like crazy, jumping up to above the red, then falling, then holding steady. Eventually, the car stalled at a light, and restarted right away, but this time with no tach. The car has been running great, with no problems, other than the tach not working. That's my first situation.

I was thinking maybe the CPS or CID was bad, so I went to check out getting new ones. All of the online SHO vendors have the CPS for around $100, and the CID for about $40... I went to Autozone and they gave me the prices of $42.99 for the Crankshaft Position Sensor (part #SU242), and $29.99 for the Camshaft Position Sensor (part #F134). Should I buy the Autozone sensor?

The car is still running great... just no tach, now. Will I start to have other problems soon, or could this be isolated to the tachometer, and not related to the CPS or CID? (Just like Pete said in his earlier post)

I pulled the codes just now, and got:
KOEO
511 - I expect this with the LPM
542 - Maybe from the time it stalled?
211 - AaaHA! It a CPS Code..."

KEOR
225 - Hmmm... so I tried it again

111 - All clear KEOR

I'm going to clear the codes, then see if the 211 comes back... I'm thinking it will.

Advice.?.. is the AutoZone CPS good to go?

Also... how bad is it for my car to drive with a bad CPS? I need to go to work, but don't want to hurt my baby...

<small>[ July 10, 2002, 03:31 PM: Message edited by: Cohiba ]</small>

 

[SLOSHO89]

Try checking the fuse for your tach. I don't remember which one it is, but it also controls some of the dash lights.

Efren

 

[luigisho]

The Autozone sensors are fine. I have heard good and bad about the aftermarket IAB, but the other sensors seem ok. For the price you could replace both.

 

[1stGenSHO]

I have used the Autozone CPS and CID sensors with no problem on my '90.
I have never heard of one of these sensors going without the car running like crap though. Check out that tach before you go through the trouble of replacing a sensor that is probably ok.
1stGenSHO

 

[pete c]

QUOTE] Sheeesh... obviously. It's called a SHO, not a "show"!

hey, you try typing at 3:44 in the morning!

 

[Cohiba]

hey, you try typing at 3:44 in the morning! [/QB]

Did you notice my post times...? I don't sleep much.

 

[pete c]

that might explain posting the same thread 4 times.