I need to set up TPS on '93 SSE

[tripper225]

Hi, I haven't posted in a long time, my car didn't stall so much when weather was cold.

I removed TPS to test because I couldn't make good contact with ohm meter while TPS was installed. It checks out 0 to 5K one side and 5K to 0 on the other. I put it back on and I got code 17, 21, and 22, which means spark reference failure, TPS low voltage low, and TPS high voltage high. I checked the manual and it says that we should put a reference mark on the sesnor before removing; and reinstall in marked position. Well, I missed that step so I loosened the sensor and biased it to have slight deflection at idle position (the clearance holes have only a little clearance). Problem is I still get code 17, and 21. The manual also states that a shop adjustment may be required. Do any of the gurus know how to measure correct TPS adjustment.

There is some other quirks that occur now that had not previously:
1. Engine cold idle 2000 rpm I have to wait about 30 seconds and kick it down like we used to do carbuerated engines.
2. Transmission downshifts at 65mph; 3000 rpms so it is probably shifting just below overdrive.

These are new to this car never had these before

Regards,
Jim

[big white bufflo]

.93 v is what i set my 92 buick up at and have no trouble if you have a scan tool it makes it easyer but you can use a volt meter

[tripper225]

Thank you for the reply Big White Buffalo.

I haven't made this adjustment before. Is it possible you could give me the specifics on this adjustment.

Where to connect volt meter probes?

What to loosen to make adjustment?

It sounds like just having the ignition key on will provide current to the TPS, if the engine must be running please respond.

Your kind attention to this matter is appreciated,

Regards,
Jim

[maxwedge]

All the info is at autozone.com, repair guides.

[big white bufflo]

to adjust the sensor loosen both screws then slightly tighten one so you can move the tps around im not two sure on what wire you connect to but just prod around with one to ground red as your test one the three wires will give you a signal of less than one volt good luck on the doit your self repair it not hard and you learn as you go

[HotZ28]

You have three wires, Black is ground, Grey is the reference voltage and should measure 5.0v and the Dark Blue wire is variable voltage feed to the PCM. The voltage on the blue wire should read .05v @closed throttle and progress to 4.0+v @ WOT. All testing can be done with ignition ON, engine off. Position the throttle valve in the normal closed idle position, then install the TP sensor on the throttle body assembly, making sure the TP sensor pickup lever is located above the tang on the throttle actuator lever. You should feel spring pressure on the TPS tab when installed correctly. High idle would indicate, high voltage on the blue wire @ closed throttle!

[Jrs3800]

The TPS for the 93 Models is set it and forget it... There is no adjustment for the TPS on the 93+ 3800 V6..

[tripper225]

Thank you all for your replies. It appears that each of the replies is correct. There is some adjustability of the TPS but it is minimal because there is only clearance holes.

Also, there is good info at the Autozone website. The test is much easier with a cable connector from a junker, and checking the reference voltage, and output of the voltage divider. It checks .49 volts at closed throttle and 4.37 at WOT. The info at the Autozone site says it should show 5.0 volts at WOT. Is this a problem?

Also, the transmission still shifts down to 3rd at 65 mph, can a TPS malfunction cause the downshift, or am I looking for another problem?

Also, is there a way that I can still get these codes at the same time:
17 Spark reference circuit failure
21 TPS low voltage LOW
22 TPS high voltage HIGH

Thanks,
Jim

[Jrs3800]

Do you have any other codes other than what you listed?

And yes the TPS can cause a lot of driveability issues for any 3800 V6

[tripper225]

I just checked the ECM two minutes ago. All I get is 17, 21, 22. I'm starting to wonder if knowing what the voltage output of TPS is at 30mph and 60mph would be useful. Because the TPS on the car only puts ot 4.37 volts max.

[HotZ28]

Originally Posted by tripper225

It checks .49 volts at closed throttle and 4.37 at WOT. The info at the Autozone site says it should show 5.0 volts at WOT. Is this a problem?

No, that is perfect!

Also, the transmission still shifts down to 3rd at 65 mph, can a TPS malfunction cause the downshift, or am I looking for another problem?

You have another problem, it could be the PCM!

Also, is there a way that I can still get these codes at the same time:
17 Spark reference circuit failure
21 TPS low voltage LOW
22 TPS high voltage HIGH Thanks,
Jim

Yes, if you have a bad ICM, PCM, CKPS, or TPS, but the voltage looks good on the TPS.

[tripper225]

Thanks for the info.
I have checked the CPS and cam sensor with an oscilloscope so, they may okay unless they fail at elevated temperaure. I have also had the ICM checked at autozone, they cycled it 4 times so that it would heat up a little. It checked fine. How do I check the PCM?

Jim

[tripper225]

I need to leave a post to let everyone know how I made out.

The tps codes kept coming back so, that was the first thing I changed.

The stalling or no start continued.

Once while visiting a friend the car didn't start for two hours; the longest wait I had during this two year ordeal. My friend mentioned that the IAC can cause no start; just tap it lightly a couple times and try it. It started immediately. I tried to clean and reinstall the IAC but I still had stalling at idle or no start. Changed to a new IAC.

The last problem was stalling at high speed. I retested the CPS with my oscope and everything looked good on both channels. In October 2009 I finally decided to change the CPS, because the weather was getting cold again, and since then no stalling.

The only issue now is the down shifting. I know that I read somewhere that if you are driving at constant highway speed, and touch the brake pedal while maintaining the accelerator pedal with your right foot, if the transmission downshifts there is a problem with the ECM or the PCM. during this test I do not use the cruise control, and the tach registers an increase of 700 rpms. Can anyone help me narrow down which one it is?

Thanks for the responses, hope this helps someone else.
Jim

[Jrs3800]

Your TCC circuit runs through the switch on the brake pedal... When you tap the brakes the TCC will and should release, this is not a downshift, its the TCC releasing.. This will also release the cruise control( all you do it hit resume and it will pick up and go )... what you describe is normal for the TCC System..

[tripper225]

The initial conditions are as follows:

Engine and tranny warmed up.

Level highway speed limit 65 mph

Maintain speed with accelerator pedal, no cruise control.

With right foot on gas pedal maintain gas pedal setting to stay at 65 mph, tap brake pedal three things occur.

1. car maintains speed as before brake pedal depress.

2. Tach increases to 3000 rpm

3. Engine noise raises in pitch, I'm thinking the transmission shifts down.

Another occurence was during cold weather in January, the tranny shifted down at 65 mph, the tach registered 3000 rpm without depressing the brake pedal and I drove all the way to work (approximately 7 miles further) after it shifted down. I tried hand shifting from overdrive to drive several times and back to overdrive and the tranny did not shift up to overdrive. The tach stayed at 3000 rpm until I got off the highway.

I'll look into the TCC feature and see if it will do this.

Thanks,
Jim