TPS Issue, Brand new TPS...
05-20-08, 11:45 AM
#1
TPS Issue, Brand new TPS...
To start, I have an 86 GXL, and I just bought a brand new TPS from Atkins Rotary. I recently started having idle problems, so I went to adjust my fast idle screw and the thing is all the way down, even though I'm idling at about 1200rpms. SO I thought my TPS may need to be adjusted since the last time I did it, I used the LED thing that I made myself. The car was warmed up and "In the ON position," But nothing I did with the TPS adjusting screw would make anything light up. I know the LED's work, because when the engine is running, and I push the throttle open, I can make them light up like they should when adjusting the TPS.
Anyways, I adjusted the TPS by ear till she was idling right above 900RPMs, but she's still very erratic, and I'd like to figure out what is going on... Anyone have any suggestions? I've already searched...
Anyways, I adjusted the TPS by ear till she was idling right above 900RPMs, but she's still very erratic, and I'd like to figure out what is going on... Anyone have any suggestions? I've already searched...
05-20-08, 03:18 PM
#2
HAILERS
Join Date: May 2001
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The TPS does not adjust the idle speed or fuel mixture at idle.
Something is holding your throttle plates open a bit too much. Most likely the water thermowax unit. See the free online FSM, Fuel and Emissions seciton on *how to*. You virtually have to remove the throttle body to ajust it on a non turbo car/engine.
Another SLIGHT possibility is the BAC itself. Remove its plug and see if the idle speed is effected or not.
Something is holding your throttle plates open a bit too much. Most likely the water thermowax unit. See the free online FSM, Fuel and Emissions seciton on *how to*. You virtually have to remove the throttle body to ajust it on a non turbo car/engine.
Another SLIGHT possibility is the BAC itself. Remove its plug and see if the idle speed is effected or not.
05-20-08, 09:09 PM
#3
This I know, but I thought it may have been stuck or being held in a wrong position because of a bad adjustment.
The Issue I'm concerned with is not actually the Idle, I can live with it at 1KRPMs, What I'd like to know is what is going on with my TPS, Has anyone seen this before?
Something is holding your throttle plates open a bit too much. Most likely the water thermowax unit. See the free online FSM, Fuel and Emissions seciton on *how to*. You virtually have to remove the throttle body to ajust it on a non turbo car/engine.
Another SLIGHT possibility is the BAC itself. Remove its plug and see if the idle speed is effected or not.
Another SLIGHT possibility is the BAC itself. Remove its plug and see if the idle speed is effected or not.
05-20-08, 09:29 PM
#4
HAILERS
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
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Because the throttle shaft is being held open too much by??????, the TPS cannot be adjusted right because there is not enough adjustment in the TPS screw.
That's not real clear, but it's the best we can do. It's much like if you had a PERFECT car and the outside air temp was in the 30's and the engine was stone cold. With the engine cold like that, you would not be able to adjust the TPS, because there would not be enough adjustment left for the TPS screw. Why is that? Because the water thermowax's piston would be fully retracted making the linkage hold the throttle plates too far open.
Once that PERFECT car was warmed up from 30*F to a runing temp of 180*F, then the linkage would have settled to fully closed and the TPS screw would now have enough adjustment to work according to the procedure in the FSM.
Remove the throttle body. Look at the fast idle cam and the roller it rides on plus look at how far the throttle plate is open. Now pour boiling water over the outside of the water thermowax and watch its piston extend and make the throttle plates fully close. Something like that.
Your problem seems to be water thermowax related due to????? mal adjustment by someone or a malfunctioning thermowax piston/linkage. It's buggered up.
Or to exaggerate the problem, look at it like this. Go hold the throttle open about half way. Now look at the TPS and its adjustment screw. You can readily see there's no way on God's green earth that moving that screw is going to adjust squat, until the linkage is released and the throttle moves to fully closed. Something like that.
That's not real clear, but it's the best we can do. It's much like if you had a PERFECT car and the outside air temp was in the 30's and the engine was stone cold. With the engine cold like that, you would not be able to adjust the TPS, because there would not be enough adjustment left for the TPS screw. Why is that? Because the water thermowax's piston would be fully retracted making the linkage hold the throttle plates too far open.
Once that PERFECT car was warmed up from 30*F to a runing temp of 180*F, then the linkage would have settled to fully closed and the TPS screw would now have enough adjustment to work according to the procedure in the FSM.
Remove the throttle body. Look at the fast idle cam and the roller it rides on plus look at how far the throttle plate is open. Now pour boiling water over the outside of the water thermowax and watch its piston extend and make the throttle plates fully close. Something like that.
Your problem seems to be water thermowax related due to????? mal adjustment by someone or a malfunctioning thermowax piston/linkage. It's buggered up.
Or to exaggerate the problem, look at it like this. Go hold the throttle open about half way. Now look at the TPS and its adjustment screw. You can readily see there's no way on God's green earth that moving that screw is going to adjust squat, until the linkage is released and the throttle moves to fully closed. Something like that.
