Urgent Help Please - TPS - Car Undriveable !

[ra23celica]

Thanks mate, I will look at that next.
In the meantime, I got these numbers when I hooked up the multi-meter, but I don't have the base spec's.

Closed throttle VTA - E2 just 80 ohm - 4AGE lists 200 to 800 Ohm

Wide Open Throttle VTA - E2 12 to 14 Kohm - 4AGE 3.3 to 10 Kohm.
Wide Open Throttle VC - E2 5 Kohm, 4AGE lists 3 to 7 Kohm - so spot on here.

[CrUZida]

The ONLY pins you need to measure are E2 and IDL.
With the throttle 100% closed, E2 and IDL should be continuous.
With the throttle just cracked enough to raise the revs a few hundred, the E2 and IDL contacts should go open circuit.

If once you know you have this set, and the car is still playing up, the TPS is probably stuffed.

[ra23celica]

Thanks Peewee.
Checked the throttle plate and it shuts fully.
I will look at those pins and attempt to set it up as per that.
Cheers,
Mitch.

[The Witzl]

the feeler guage method for adjusting a TPS is all but fundamentally uselss. good in theory, shit in execution.

install, run and adjust. got it right? disconnect the battery for 5 mins, and on restart, se if she stays in tune...

Shit in execution how? I've done the TPS calibration/testing by feeler guage about 15-20 times now, and each time things are improved over how they were before (if TPS was out of position to begin with).

I will agree that doing it is a PITA, but after a little practice, and a little patience, it's not too hard at all.


As for the comments about the TPS not being under spring tension when installed.... thats only half true. On many TPS sensors, you have to rotate the inside of the TPS unit about 20deg to line it up with the throttle butterfly and the correct position for the IDL switch. It wont be under much tension, but it is under a little tension.

Perhaps our friend here has installed the TPS such that it's tabs are on the wrong side of the "wingnut thingy" tabs that rotate the TPS's guts?? I know ive done it before!

[JustCallMeOrlando]

As for the comments about the TPS not being under spring tension when installed.... thats only half true. On many TPS sensors, you have to rotate the inside of the TPS unit about 20deg to line it up with the throttle butterfly and the correct position for the IDL switch. It wont be under much tension, but it is under a little tension.

Perhaps our friend here has installed the TPS such that it's tabs are on the wrong side of the "wingnut thingy" tabs that rotate the TPS's guts?? I know ive done it before!

This is what I meant. It clips over the wingnut, and then has to be rotated slightly to line up with the screw holes.

And that is exactly what I did Just make sure it stays in the little grooves Mitch, assuming it's the same as my GTE.

[ra23celica]

I have read over this thread again and spent a few long hours into the (hot) night last night, and still have not got this car running.

Witzl - when I intall the TPS it is under a little tension and I have checked that the tabs inside the sensor line up with the wingnut on the throttle plate lever. How do I make sure that it is also in the correct position for the IDL switch?

JCMF - I will check again that I have the wingnuts in the groove mate, and I am sure its the same as your GTE.

So, last night this is what I did / found:

The throttle 'wheel' does not rest on the stop screw, when the engine is shut down, but I read somewhere that the dashpot usually cracks the throttle open a smidge when the engine is off.

I have fitted a return spring for the throttle wheel in place of the missing throttle return cable.

I could not get the TPS adjusted properly so I set the thing at 12 o clock and 6 o clock with the two screws and measured the only two things I could with my multimeter, ohms at 0 throttle and at WOT.

At 0 the VTA - E2 reading was 0.080 to 0.100 k ohm, and that is well below every Toyota spec I can find from other engines, which state 0.2 - 0.8 k ohm.

At WOT VTA - E2 was 12 to 14 k ohm, well above every other range I could find, which lists 3 to 10 k Ohm generally.

With VTA being common to both measurements (VTA - is throttle valve opening angle) I wonder if I have stuffed the TPS and need a new one.

Witzl - I am saving up the airfare to fly you and Sideshow over to Perth to work on my car!

[CrUZida]

You coming to the dyno day?
Bring it then and we shall fix it.

[ra23celica]

That is a great offer mate - much appreciated.
I have the problem in - how will I drive it here?
Bunny hops in the Toyota might look cool at Easter, but not when Hyundai drivers are laughing at me...

[CrUZida]

If you have having problems at revs apart from idle, I'd be suggesting the TPS is fucked.

If its out of adjustment, then it should still drive fine, but be a bitch at idle.

[ra23celica]

It's option one mate, definately option one.....sigh....I must have rooted in when I took it apart. I will change it and fit some hex head screws to make it easier to reach the bottom adjustment point.
Cheers,
Mitch.

[Merudo]

If you have having problems at revs apart from idle, I'd be suggesting the TPS is fucked.

If its out of adjustment, then it should still drive fine, but be a bitch at idle.

so my car seemingly having a rev limiter at 3000rpm when i have the TPS connected leads you to believe it's stuffed?

[CrUZida]

Depends, there are other things that could cause that.
Poor spark, poor fuel, etc.

[Merudo]

keep in mind the car runs fine without it connected... i was told that should be okay to drive without it connected as long as i dont rev it higher than 5000 / 5500rpm


but thats okay, im getting a new one soon anyway with some other stuff.

[brett_celicacoupe]

hi,


i had the EXACT same thing happen when i first started my 1ggte.

the motor would constanly go: vvvrrrrrrrrrrRRRRRR.....duuuuuuuurrrrrrr.......... vvvrrrrrrrrrrRRRRRR.....duuuuuuuurrrrrrr..........

ie. reving from idle to ~2000rpm, then cutting out, over and over again


i had a good look at the ISCV and noticed it was clogged up and pretty well fully open. so, i cleaned it and manually closed it (rotated shaft by hand). then i re installed it and adjusted the idle via that little screw on the throttle body. it worked okay but the computer wasnt controlling the idle

a couple weeks later i found out that the 2 midle pins of the ISVC plug had to have a 12v +ive power supply for the ISVC to function properly. so i hunted down the wires in the loom and and connected them up and walla!! ISCV worked


so what i reckon you should do is check the middle 2 pins of the ISCV have a 12v +ive power supply when the ignition is on.

ie.

....|........|
-->|........|<---
....|........|


i think what is happening is that the computer is recoagnising that the TB is @ idle so it sets XX amount of fuel. however your ISVC is probly open so air is bypassing the TB. so there is WaaaaaaaY to much air entering

hope this helps anyway.

PS: did you get the bellhousing ?

[brett_celicacoupe]

and if you want to do a quick check to see if ISCV is working properly, pull the hose off at the manifold and block both ends. note that you need to idle it by foot when you are doing this. but if it doesnt rev wildly, i reckon this is the issue