The good news and the bad news!

[DJmart]

The good news is!!! The BHG job is done! The motor is all back together and running strong (200miles so far!)

Bad news... I disconnected the TPS sensor and removed it because I was concerned about it getting wet as I was cleaning the throttle body and such. Turns out, I probably shouldn't have done that.

I am having a heck of a time getting the ECU to see it properly. I remember it was basically smack dab in the middle of the hole (equal gap on both sides of the adjustment) top and bottom.

I put it back that way, and if the connector is in, the engine will go up to 2500,3000k and cut fuel and drop back down, repeatedly.

How do I synchronize and set this TPS so everything works properly?

I have it disconnected at this time and have been driving around with it unplugged for 200miles, but i doubt that is good.

Let me know!

-DJmart

 

[hvyman]

Loosen the screws with the engine running and the sensor should snap back to one side. Very gently start turning it the other way. When it deflects or drops from(guess) say about 1100 to 800rpm tighten the screws. Thats it.

Edit: thats with it plugged in.

 

[DJmart]

Loosen the screws with the engine running and the sensor should snap back to one side. Very gently start turning it the other way. When it deflects or drops from(guess) say about 1100 to 800rpm tighten the screws. Thats it.

Edit: thats with it plugged in.

It will snap back to a more closed throttle, so the RPM would be raising if i turned it the opposite way. Would I tell the difference right away?

 

[Poodles]

Set: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=103
Check: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

The prongs on the little rotor on the throttle body slide into slots on the rotor of the TPS, it doesn't just rest against it.

 

[DJmart]

Set: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=103
Check: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

The prongs on the little rotor on the throttle body slide into slots on the rotor of the TPS, it doesn't just rest against it.

That might be worth checking out, maybe it isn't in the slots, although I think it might be.

 

[hvyman]

If it snaps back then its in right.

 

[DJmart]

If it snaps back then its in right.

It was definitely in there right.

I went verrry slow from where it snapped back to around 1100rpm and it did not show any signs of the RPM dropping.

Any other ideas? I remember going through that multimeter deal not too long ago and that didn't work out that well either.

Could the TPS be bad because I took it out? or is it just not synchronized to the ECU?

 

[hvyman]

You dont mess with the throttle just turn the sensor.

If it doesnt do anything its prolly bad and a multi meter will tell you that.

 

[mkiiichip]

likely vacuum leak, tps adjustment wont make your engine surge.

EDIT: bubbles in cooling system also will cause this

 

[DJmart]

likely vacuum leak, tps adjustment wont make your engine surge.

EDIT: bubbles in cooling system also will cause this

I did burp the cooling system so I don't think there are any bubbles, although, if I did have a vacuum leak, why would the issue only persist when the TPS is plugged in? otherwise its free revving?

 

[mkiiichip]

Check: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

You may have a tps issue but it is not adjustment related. if you are sure it is installed properly, do the checks Poodles mentioned.

I would be interested to know what the voltage at VTA is, fully closed and fully open.

 

[jetjock]

A faulty TPS will make the engine surge (rpm cut) if the throttle is opened beyond a certain point but the TPS (or wiring) has to fail a certain way and the surging shouldn't occur quite at those rpms.

Regardless, it's a simple matter of checking codes to see if rpm cut is the culprit or if it's something else. If code 51 *does not* appear when the throttle is cracked rpm cut is involved. Also, if the surging stops after unplugging the TPS it's another indication rpm cut is likely being invoked by the ECU.

All that said VTA is is not involved with fuel cut. It's an IDL only issue.

 

[DJmart]

A faulty TPS will make the engine surge (rpm cut) if the throttle is opened beyond a certain point but the TPS (or wiring) has to fail a certain way and the surging shouldn't occur quite at those rpms.

Regardless, it's a simple matter of checking codes to see if rpm cut is the culprit or if it's something else. If code 51 *does not* appear when the throttle is cracked rpm cut is involved. Also, if the surging stops after unplugging the TPS it's another indication rpm cut is likely being invoked by the ECU.

All that said VTA is is not involved with fuel cut. It's an IDL only issue.

This is good information.

When you say codes, does that mean I need a CEL to be able to check for them?

Thanks!