2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

TPS goes bad with 3 different times?

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Old Nov 22, 2008 | 09:30 PM
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TPS goes bad with 3 different times?

Ok so ever since I've had my FC the TPS seems to go bad in the car. The car starts up fine and no problems at all, after its warmed up the idle starts to become bouncy. So I went a friend came by with 2 TPS and he puts the first one on and then the idle is bouncy still. Replaces it with the 2nd one and then messes with the adjusting screw and then the idle becomes normal. Well since he messed with the adjusting screw when the car is started cold it jumps to 4k instead of 3k. When the car idles it idles at 2k instead of 1k. Is my TPS bad or do I need to adjust it and it should be fine?
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Old Nov 22, 2008 | 09:40 PM
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You definitely need to do some adjustments on both the TPS and the TB to get the iddle to where it should be.
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Old Nov 22, 2008 | 10:41 PM
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I'll be adjusting the TPS by following this guide tomorrow. http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1

Anything else I should do also?
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Old Nov 23, 2008 | 06:07 PM
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Ok I did the whole led thing today I have it so that only one LED is lit. But when you rev the engine both lights lite up. Is this exposed to happen?? Everything seemed fine after I got one light lit. But about 7 mins later the bouncy idle returned. Why does it do this!!! Please someone help me!
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Old Nov 23, 2008 | 06:27 PM
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do you have any stalling problems?
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Old Nov 23, 2008 | 06:29 PM
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Originally Posted by Toddy
do you have any stalling problems?
yes i dont know why either
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Old Nov 24, 2008 | 07:51 PM
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anyone have any suggestions?
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Old Nov 24, 2008 | 10:17 PM
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I messed with the screw ontop of the throttle body or aas ( air adjusting screw ) supposedly you can adjust the idle by messing with it. Well now the car runs worse since I fucked with it.
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Old Nov 24, 2008 | 10:55 PM
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Originally Posted by FcJohnny
Ok I did the whole led thing today I have it so that only one LED is lit. But when you rev the engine both lights lite up. Is this exposed to happen?? Everything seemed fine after I got one light lit. But about 7 mins later the bouncy idle returned. Why does it do this!!! Please someone help me!
The TPS can only be set at an idle speed below ~1100 RPM. So in other words, when the engine is fully warmed. If you blipped the throttle, then of course the resistance value of the TPS would have changed and made the LEDs light up. You want to get 1 LED on at the set idle speed.

Personally, I prefer to set my TPS by voltage. Backprobe the "A" wire w/ the positive lead of a multimeter and touch the negative lead to the (-) battery terminal. If you're at 1.0 volts, it's set. If not, turn the screw until it gets there.

1) Set the TPS again to be sure
2) Fine tune the mixture with the variable resistor (make sure you jumper the inital set coupler first)
3) Adjust the idle speed up/down with the air bypass screw (again, set the coupler first)

If you still can't get it to work, search for vacuum leaks.
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Old Nov 25, 2008 | 12:04 PM
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the car wont even idle anymore. it just starts jump to 3k then it starts to die. when i give it gas to keep it alive it will instantly
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Old Nov 25, 2008 | 03:01 PM
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could be the Air Flow Meter as well.... or a major vacuum leak. I myself am saving up to buy a brand new TPS jsut cuz I'm tired of worrying about used ones going bad on me.
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Old Nov 25, 2008 | 03:33 PM
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i have somewhat identicle symptoms.. check for vac leak, check your BAC valve, and adjust the TPS n TB.
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Old Nov 25, 2008 | 03:38 PM
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vacuuum leak. also make sure the afm is in the right position
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Old Nov 25, 2008 | 03:48 PM
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Make sure the fast idle cam releases completely when the engine is warm. This will allow the throttle plates to close completely. Only then adjust the TPS. At the back of the TB, you'll see the water valve and another cylinder that has a plunger type of thing that comes out as the wax or something heats up. This presses against the fast idle cam (through an adjustment screw). If you push that down manually, you'll see the throttle plates close to idle. I usually press this manually, just to make sure I'm setting the TPS with the throttle closed.

You'll see some pics. of the fast idle assembly in the fuel and Emissions chapter of the FSM, linked below.

Oh, and yes, you may also have vacuum leaks.
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Old Nov 25, 2008 | 07:32 PM
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the afm has to be pointing in a certain direction? I can't adjust the TPS or anything since the air dies right after its cranked...... I jumps to 3k rpms then it dies when I try to give it gas so it will stay alive it will die instantly

also to check for a vaccum leak should i just spray wd40 on the lines and see which one kills the engine or makes the rpms drop?
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Old Nov 25, 2008 | 08:34 PM
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Originally Posted by FcJohnny
the afm has to be pointing in a certain direction? I can't adjust the TPS or anything since the air dies right after its cranked...... I jumps to 3k rpms then it dies when I try to give it gas so it will stay alive it will die instantly

also to check for a vaccum leak should i just spray wd40 on the lines and see which one kills the engine or makes the rpms drop?
Set the TPS with the key in the 'ON' position. It doesn't have to be running, but the motor needs to be warm or the fast idle cam needs to be rotated to let the throttle plates rest further closed.
http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1

Spraying liquid near a vacuum leak will make the idle speed increase, but if it won't run long enough, you can't do this anyway. Inspect vacuum lines instead.
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