92 Cutlass Ciera SES Problem?

[gotts]

Alright, total newbie here, so please don't throw me to the wolves too soon!

I have a 92 CC 3300 V6 108,000 miles (yes, I know, pretty low mileage!)

The other day when I was warming my car up (as it got down to -15F the other night) there seemed to be a change in the sound of the idle, almost like it got faster.

I proceeded to start driving and after about a minute, the SES light comes on and the speedometer sticks at 0. Also noteworthy is that the brakes seemed "harder" when you press the pedal (sorry for the non-technical terms).

I was in no place to pull over, so I had to keep driving. It went fine for about a half a mile when the light disappears and the speedometer starts working again.

I'm out of the woods, right? Wrong. At the next stop light the car stalls/quits but fires right back up after starting it again. SES light is back and speedometer at 0 again. I manage to milk it to work and hope for the best getting home.

Starting it after work, starts fine, let it warm up, 1 minute later, SES light comes on, speedometer sticks. I'm only about 3 minutes from home, so I try to milk it back home.

The new problem this time is whenever I was at a stop, the power/electrical system seemed as if it was about to fail. As soon as I accelerated, the power seemed to return, with the SES on/accelerator at 0.


I know I need to take it in to get looked at, but do you guys have any ideas of what to look for so I'm not in too deep?

Within the last 3-4 years I've replaced the battery and the alternator. I seem to be leaning towards a sensor problem... maybe something to do with the recent drop in temperature?

Thanks for your help!

[xeroinfinity]

Welcome to AF.

Get it scanned for trouble codes, no other way to know for sure why the SES lights on.

Your other troubles sound like a power issue, test the battery voltage should be at least 12.5-13.5 votls with the engine off, should read more when the engine is running, 14.5votls or more.

Also I'd check that the connections are clean and tight.

When it is under 30 deg's your idle is suposed to be higher.

Hope that helps.

[gotts]

Originally Posted by xeroinfinity

Welcome to AF.

Get it scanned for trouble codes, no other way to know for sure why the SES lights on.

Your other troubles sound like a power issue, test the battery voltage should be at least 12.5-13.5 votls with the engine off, should read more when the engine is running, 14.5votls or more.

Also I'd check that the connections are clean and tight.

When it is under 30 deg's your idle is suposed to be higher.

Hope that helps.

Thanks for the reply. I figured I'd need to get it scanned, but it was worth asking anyways!

I'll share what I find out.

[gotts]

Had it checked out, came out code 12. Throttle sensor? They cleaned it off and it worked fine for 2 days. Now it's acting up again. Either replace the sensor completely or maybe a computer problem?

[xeroinfinity]

The code(s) stored in memory may be read through counting the flashes of the dashboard warning lamp.
The dash warning lamp should begin to flash Code 12.
The code will display as one flash, a pause and two flashes. Code 12 is not a fault code.

It is used as a system acknowledgment or handshake code; its presence indicates that the PCM can communicate as requested. Code 12 is used to begin every diagnostic sequence. Some vehicles also use Code 12 after all diagnostic codes have been sent.

After Code 12 has been transmitted 3 times, the fault codes, if any, will each be transmitted 3 times. The codes are stored and transmitted in numeric order from lowest to highest.

The TPS is cheaper then a ECM/PCM.

Hope that helps.

[gotts]

Originally Posted by xeroinfinity

The code(s) stored in memory may be read through counting the flashes of the dashboard warning lamp.
The dash warning lamp should begin to flash Code 12.
The code will display as one flash, a pause and two flashes. Code 12 is not a fault code.

It is used as a system acknowledgment or handshake code; its presence indicates that the PCM can communicate as requested. Code 12 is used to begin every diagnostic sequence. Some vehicles also use Code 12 after all diagnostic codes have been sent.

After Code 12 has been transmitted 3 times, the fault codes, if any, will each be transmitted 3 times. The codes are stored and transmitted in numeric order from lowest to highest.

The TPS is cheaper then a ECM/PCM.

Hope that helps.

This I knew. It's just a little upsetting that when I took my car to get serviced and I asked what code it was reading, they went on to tell me code 12, and say throttle positioning sensor. Im guessing it was meant to be a 21 or 22. Printout they gave me said 12, though... I'm kind of confused.

Once I looked at the symptoms, it seems like there's a high volatge on the TPS, most likely a code 21.

I was driving at about 40-45 MPH last night and the car just seemed to stall out.

If my research was correct, TPS helps control the ignition timing and fuel injection? So if it's functioning incorrectly, it'll overcompensate and change the fuel injection, possibly causing the car to stall?

Like, if it were misreading that the throttle was too far open, it could lessen the amount of fuel injected?

I'm just looking to see if I fully understand what my problem may be, so I can have a better understanding of the hit on my wallet

[xeroinfinity]

IT is pretty easy to test the TPS to see if its in range of operation.

The TPS provides the ECM with information on throttle position in order to determine injector pulse width to get the correct air fuel mixture.

At closed throtle the voltage(w/key on) it should be about .04 volts and as the throtle opens the voltage should gradualy increase up to aprox 5volts.

If the voltage right, or the voltage rise isnt steady and is irratic, the TPS is bad.

Let me know what you find out.

[gotts]

Originally Posted by xeroinfinity

IT is pretty easy to test the TPS to see if its in range of operation.

The TPS provides the ECM with information on throttle position in order to determine injector pulse width to get the correct air fuel mixture.

At closed throtle the voltage(w/key on) it should be about .04 volts and as the throtle opens the voltage should gradualy increase up to aprox 5volts.

If the voltage right, or the voltage rise isnt steady and is irratic, the TPS is bad.

Let me know what you find out.

Could a faulty/disfunctional TPS cause the car not to fire because it's not getting enough fuel? Something wrong with the fuel injection?

I tried starting the car the other day and it turns over for about a half second, then it dies. If right after it fires I put on the gas, she stays running. Something throttle-related for sure?

I'm not able to have it checked out later this week, but from my research and previous symptoms its gotta be the TPS or something leading to it, like the wires.

Any feedback/other suggestions?

I'll let you know what I find.

[xeroinfinity]

yes, it wouldnt hurt to change the TPS at this point.
If its the original it's lived way beyond its life. Pretty cheap too, $15-20.

[gotts]

So I have my car in today and supposedly the computer on it is bad. They tested the TPS and it turned out okay, so I'm hoping that this solves the problem.