getting crazy with ignition timing
- Thread starter azerty
- Start date
Texx
Super Moderator
Again I would ignore that reading. The TPS is just a switch that is either ON in one position for idle or ON in the other position for WOT, anywhere in between the TPS should not make any connections. A throttle position % reading would only be relevant for a linear type TPS that has a variable resistance.
With the throttle closed the IDL pin at the ECU should be grounded to E2 (common sensor ground pin9 16P ECU connector) by the idle contacts in the TPS and so pin 12 of the 16P ECU connector should show 0 volts. If you see a voltage reading at that pin with the connector still connected to the ECU, then either the idle switch in the TPS isn't closed, there is another break in the circuit somewhere between IDL pin 12 and E2 pin 9 or if your voltage reading is between 0.1v and 4.9v there may be a resistance (such as a poor connection) somewhere between IDL pin 12 and E2 pin 9.
As weeJohn suggested, shorting the IDL and E2 pins of the TPS connector with a jumper wire would be the quickest way of identifying a problem with the TPS.
With the throttle closed the IDL pin at the ECU should be grounded to E2 (common sensor ground pin9 16P ECU connector) by the idle contacts in the TPS and so pin 12 of the 16P ECU connector should show 0 volts. If you see a voltage reading at that pin with the connector still connected to the ECU, then either the idle switch in the TPS isn't closed, there is another break in the circuit somewhere between IDL pin 12 and E2 pin 9 or if your voltage reading is between 0.1v and 4.9v there may be a resistance (such as a poor connection) somewhere between IDL pin 12 and E2 pin 9.
As weeJohn suggested, shorting the IDL and E2 pins of the TPS connector with a jumper wire would be the quickest way of identifying a problem with the TPS.
azerty
Supermoderator
yeah I know it is On/off switch. so it will only show 0% or 100%
but as I got a On/off reading from throttle signal to ECU which is 4,98v when throttle is closed and 0 volt on full throttle, once again I asumed it was working fine. but I might have missed something btw, glanza and GT TPS aren't working the same. Glanza one are reverse type (0 volt when full throttle)
I still can try shorting IDL and E2 thought and see what happens
but as I got a On/off reading from throttle signal to ECU which is 4,98v when throttle is closed and 0 volt on full throttle, once again I asumed it was working fine. but I might have missed something btw, glanza and GT TPS aren't working the same. Glanza one are reverse type (0 volt when full throttle)
I still can try shorting IDL and E2 thought and see what happens
Texx
Super Moderator
I can only go by the circuit diagrams, but looking at both the genuine EP82 and EP91 4E-FTE diagrams I have, both TPS work the same by switching the IDL and PSW termninals to E2 sensor ground.
The TPS isn't just a straight ON or OFF. It has 3 pins. At idle it shorts pins 1 and 2, at WOT it shorts pins 2 and 3, at any throttle position in between there is no electrical contact made within the TPS.
So the TPS isn't ON for idle and OFF for WOT, it is both ON for idle and ON for WOT only in different positions. When the TPS is OFF the throttle position is somewhere in between idle and WOT.
azerty
Supermoderator
yeah, I noticed in the past while looking at EMU dataloging that TPS signal was around 5 volt from iddle up to 80 % throttle
then it was 0 volt from 80% to full throttle. EMU datalogs also show full and closed throttle. which I checked 2 days ago and was working fine
I said glanza TPS was different from GT as you were saying it was 0 volt at iddle. sorry for the confusion. (I never check gt TPS voltage in fact, it was just comments from your input)
anyway, I'll be checking this very very shortly (in 45 mins)
thanks again for your precious help
then it was 0 volt from 80% to full throttle. EMU datalogs also show full and closed throttle. which I checked 2 days ago and was working fine
I said glanza TPS was different from GT as you were saying it was 0 volt at iddle. sorry for the confusion. (I never check gt TPS voltage in fact, it was just comments from your input)
anyway, I'll be checking this very very shortly (in 45 mins
)thanks again for your precious help
azerty
Supermoderator
I've shortened from ECU side.
and ...
and ...
you were right my friend. I owe quite few beers !!
thank you for insisting !
I asumed by mistake TPS was fine, but this is the prob !!
now timing is at 10 °BTDC when distributor is a bit above middle !!!
I can hear engine sound change when I bridge and unbridge (tried while engine at iddle)
and ...
and ...
you were right my friend. I owe quite few beers !!
thank you for insisting !
I asumed by mistake TPS was fine, but this is the prob !!
now timing is at 10 °BTDC when distributor is a bit above middle !!!
I can hear engine sound change when I bridge and unbridge (tried while engine at iddle)
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Texx
Super Moderator
I'm glad you've got to the bottom of it.
Now you've got the fun job of adjusting the TPS.
http://www.toyotagtturbo.com/forums/showthread.php?47-Tutorial-TPS-setup-Procedure-weeJohn-*
Now you've got the fun job of adjusting the TPS.
http://www.toyotagtturbo.com/forums/showthread.php?47-Tutorial-TPS-setup-Procedure-weeJohn-*
Sheldon
Malta Area Rep.
glad you finaly sorted it!! texx will have some rep...
i noticed mine when i touch a little bit the tps buy hand (oushing it a bit to he firewall side) the idle will change... so id guess il be better go get a timing light on lol!
azerty
Supermoderator
Sheldon, sounds lik ea good idea !
Morpheus, maybe they were not adjusted properly
Texx, thanks for the link. I adjusted using an other trick. I moved the tps until I could hear an engine sound change. then I plugged timing light, and did check were was the contact point. it change for 10° to 20° so it is very easy to find out.
left a small gap to be sure it will read closed. job done
TGTT, definitly one of a freaking nice comunity !
Morpheus, maybe they were not adjusted properly
Texx, thanks for the link. I adjusted using an other trick. I moved the tps until I could hear an engine sound change. then I plugged timing light, and did check were was the contact point. it change for 10° to 20° so it is very easy to find out.
left a small gap to be sure it will read closed. job done
TGTT, definitly one of a freaking nice comunity !
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Sheldon, sounds lik ea good idea !
Morpheus, maybe they were not adjusted properly
Texx, thanks for the link. I adjusted using an other trick. I moved the tps until I could hear an engine sound change. then I plugged timing light, and did check were was the contact point. it change for 10° to 20° so it is very easy to find out.
left a small gap to be sure it will read closed. job done
TGTT, definitly one of a freaking nice comunity !
well done
did u do all this under diag mode...or just move the tps until u have your 10 deg?