1G Is my TPS toast? 4.6 @ pins1,4 and 3.8 @ pins 2,4

[killerwhale]

3.8 was the lowest it went. I was reading plymouthlaser.com and the guy said his was reading 0 closed?

 

[killerwhale]

Also when I open the throttle the voltage drops am I doing this ass backwards or what?

 

[DSM1G90]

The TPS is like the volume control of a radio - just a variable resistor with the center tap to send the output out

yea, you got it backwards .... trade the plus lead from the VOM between 1 and 4

Center pin "2" is where you connect the output reading. It should read "zero" when closed.

 

[killerwhale]

Mvm it's dark now had the multi at. The wring setting definitely had everything ass backwards

 

[killerwhale]

Just wanted to say thanks for correcting the nub mistake. Is it normal to get 4.6k ohms open throttle?

 

[DSM1G90]

From the tech manual: (since you have a 1993 model)"

(sorry, didn't mean to say that it should read 'zero' at close..wrong info there)

1-ignition off and remove connector
2- VOM across 1 and 4, should read between 3.5k to 6.5k Ohms
3- VOM across 1 and 2 and gradually open the butterfly - resistance should gradually change with the movement of the throttle.

If you turned the TPS, turn it to where the readings on the VOM are at the lowest with the butterfly closed, then bolt it down.

Any different readings than above, the TPS is in need of replacing..

Good luck-DSM

 

[steve]

If you turned the TPS, turn it to where the readings on the VOM are at the lowest with the butterfly closed, then bot it down.

Please don't. The correct adjustment for a 1G TPS is to turn the TPS until you see 0.48v to 0.52v on the output with the connector attached and the ECU on.

 

[DSM1G90]

You're dead right Steve - no arguements here from me on that one...Thx for bringing that one out in the light.

...for I was really wondering on that previous info that I placed above, since I've done TPS adjustments on other vehicles and they require the same voltage readings, with the system on so it is communicating with the ECU when realigning a TPS after removal to check or replacing a TPS.

I didn't want to put down what you've said since maybe Mitsu ran a different procedure in setting TPS position that I don't know about, thus why I gave the info out of a generic manual.

In fact, I do remember that there is also a bunch of separate number of steps to get both idle settings and TPS settings done so the two works together properly during operations - like you did the idle first, then the TPS settings, and some idle settings were in stages of sorts - maybe not with the DSM's but with other makes that I've done...been a while though since I did one, but still can remember some.

Don't know why that this kind of info was never placed in these off-the-counter, DIY manuals.

thx for the correction - DSM

 

[steve]

Setting the TPS on a 1G is pretty easy except for getting at the output to measure the voltage.
Having a datalogger or SAFC helps because both will tell you the voltage and all you do it turn the TPS until you hit half a volt.

The problem with the VFAQ is it doesn't account for the acceptable variations in the total resistance of the sensor (3.5k to 6.5k ohms) or to a lesser degree for the 5v sensor power not actually being 5v. The TPS functions as a voltage divider and the output voltage depends on the ratios of the upper and lower resistors to the total resistance and on the voltage across them. If you measure the values and do the math you can get the right value for the resistance. On a 2G the TPS is adjusted by where the internal IPS switches so none of this applies.

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Vout = (R2/(R1+R2)) * Vin

Since R1+R2 (pins 1 to 4) is equal to the TPS total resistance it's fixed in this application. Lets assume 5v input.
The VFAQ suggests setting the R2 (pins 2 to 4) to 0.9k

If the total TPS resistance is 3.5k, the output voltage would be 1.29v
If the total TPS resistance is 6.5k, the output voltage would be 0.7v

As you can see you get almost a 2x range in the output voltage based on the total resistance of the TPS.

I'm still working on my first cup of coffee this morning you should double check my work.
Also don't forget you can download the factory service manuals off scribe.
http://www.dsmtuners.com/forums/fre...tions/344490-download-1g-service-manuals.html
http://www.dsmtuners.com/forums/fre...stions/324090-download-2g-service-manual.html

 

[DSM1G90]

When I was doing TPS voltage readings, I would use long hat pins and inserting the hat pins where the wires would go into the back of the connector so the tips of the pins would make contact with the female pins of the connector.

Then, I could alligator clip to the exposed pins to get my voltage on my VOM when rolling the TPS.

DSM

 

[steve]

I used to do the same before I had a logger.