I'm trying to test my TPS with two LEDS, one green & one red.
I'm following procedure found in another article, where
you warm car up and turn ignition "ON".

1) This does mean that the engine is off?

That's how I understood ignition "ON" to mean. BTW I have a
1989 and the TPS has 6 pin plug & two sensors. So I take the two
LEDS and twist the Posotive leads together and crimped
a spade connector two them.
I also put a spade connector on each of the ground wires. I plug the red wires into the top of the three prong
green test plug by the air filter and pressure sensor. The
other two ground are pluged into the bottom prongs. With ignition on
I don't get any LEDS lit. So I marked the TPS screw at TDC and began 1/2 turns left than right. The leds never
lit at all either direction, so I returned to original posistion.
Now with the engine "ON" at idle speed one led is lit,
at 1/2 throttle both LEDS are lit, & at full throttle the opposite LED is lit. Does this mean anything? I believe
this test is to have Engine off and ignition on, wich then I
get no LEDS lit. The test said one LED should be lit?
BTW this is non turbo.

Brad89RX7

PS : I have low idle problems, car stalls. These symptoms worsen as the temperature outside gets hotter.
This summer has been terrible, but now that the weather
is cooler it's not as bad. Also as the Idle gets bad the pick-up
gets sluggish like it's slightly flooded at take-off.

 

You're on the right track, follow the procedure and it should work.

I found that the adjustment point where both LED's are on is very narrow and easy to miss, that is why the TPS adjustment screw has such fine threads. The car does have be warmed up to operating temperature before trying to adjust the TPS, and yes your are correct, not running but with the key in the 'on' position.

I found that as the engine cooled, if you watch the various linkages on the throttle body assembly you will see that a lot of the arms and levers move to different positions based on the engine temperature, you will not get the right setting for the TPS if the engine temperature is out of the specified range!

I did mine on a warm sunny day, faced the engine compartment directly into the sun and warmed the puppy up completly before trying any adjustments. Even with all of this I probably had less then 10 minutes to complete the procedure.

 

You can use voltage to adjust the TPS. If you search, you'll find how to do it. The advantage is that you can do it very quickly and with engine running. See FSM for what the voltages are supposed to be at idle and WOT.

You still have to make sure you don't have dead spots by checking resistance when pushing on the plunger. You should not see dead spots. IF you do, TPS is bad or dirty (clean with electrical contact cleaner)

Hugues -

 

I gues then, my TPS is bad. I warmed up engine by driving
to McDonalds about 2 miles away. I still don't get any
leds lit with engine "OFF" and Ignition "ON". I did a manuel
test where you hold the throttle at 2000rpm and push in
the sensor plungers. The one above bairley gives any reaction, but the bottom causes engine to drop in rpm.

I'll try turning the TPS scew a little slower this time and
let you know.

Thank's,
Brad89RX7

 

Turned TPS scew lowley and stoll don't get any leds to light, with Engine off and ignition on.

Brad89RX7

 

One led does light for a nano second when you first turn
on ignition.

Brad89RX7

 

IVe seen this same thing on the S5 TPS. I wasnt able to troubleshoot it thought.

The lights would illuminate for a split second... Very frustrating.

Jarrett

 

Don't waste your time with the LEDs. Use the resistance method as described in the Haynes manual.

 

Well.... I like the LED method...SO THERE....

Jarrett

 

LOL.

 

Haynes Manual?? Unless they have changed the Manual
since 1989, which is the version I have. It only tells how
to test 3 prong TPS and mine is a six prong. And this is the Manual on page 55, Chapter 1, it tells you how to put
your spark plugs in back asswards. (section 37, paragraph #9).