2750 RPM Idle after removing TB

[crholliday]

First I have to say that I dont yet own and FSM and I am hardly a competent mechanic. With that out of the way... I removed the TB cleaned it like crazy and reinstalled it. When I started her back up the idle went to 3100 then backed all the way down to 2700+ after a couple of minutes. I shut it down and restarted... same same. I am a little bit leary of dropping it in gear like that.

What could I have done wrong? I probably removed a few things I should not have... but then I may not have removed some things I should have. As far as I can tell.. everything is back where it was when I started. Is it possible that I didnt reinstall the TPS correctly? It seems like it has lots of room for movement?

Thanks for any wisdom,

Chris

 

[crholliday]

Saved by "Search"!

I had misadjusted the throttle mounting gizmo.. it was a wee too tight. But before I figured that out, I removed the EFI fuse. Now it is idling in neutral at 950. This is after 3 starts (all fully warm). I imagine I the EFI needs time to figure it all out.

Tomorrow, I'll post some pics of the inside of the manifold... oh my god is it nasty in there!

Thanks,

C.

 

[turbocruiser]

What could I have done wrong? I probably removed a few things I should not have... but then I may not have removed some things I should have. As far as I can tell.. everything is back where it was when I started. Is it possible that I didnt reinstall the TPS correctly? It seems like it has lots of room for movement?

Thanks for any wisdom,

Chris

Chris, a couple things come to mind right away.

1. The TPS requires an exact adjustment that involves feeler gauges, multimeter, and a third arm to adjust the position of the TPS, read the multimeter, and then tighten it into its proper place. There is no way to work the TPS removal and replacement and assume approximate is okay - precision is required. If it would help, I'll look up the sizes of the feeler gauges ( I think its .5 and/or .75 mm gauges ) and the voltages and the continuity settings for you.

2. If you really removed too many things to totally remember, or if you did not put those things to the correct spot, you could have something such as a vacuum hose crossed or off.

3. If for any reason you disconnected the battery, assuming everything else is exact, then it may be several start stop cycles til the computer can remember its regular settings. This is probably the least likely thing of the three, or I should say, if you managed to get the TPS, all the vacuum lines, etc. in the perfect place, then IF you disconnected the batt or the EFI fuse, this might be the problem.

 

[Rookie2]

FWIW, TPS just gets unplugged, there's no need to remove it from the TB.


Rookie2

 

[turbocruiser]

FWIW, TPS just gets unplugged, there's no need to remove it from the TB.


Rookie2

Right, but if it is removed, there is no way to guesstimate the position. Also, I remember reading somewhere that some careful selection of TB cleaner is required as some of the stronger carb cleaner products can harm the TPS, not sure for sure, but do remember reading that.

 

[crholliday]

Turbocruiser,

I did in fact remove the TPS. That is probably the problem.

 

[turbocruiser]

Turbocruiser,

I did in fact remove the TPS. That is probably the problem.

Okay,
1. Loosen the two set screws of the sensor.
2. Apply vacuum to the throttle opener tube.
3. Insert a .62mm (.024 inch) thickness gauge between the throttle stop screw and the throttle stop lever.
4. Connect the test probe of an ohmmeter to the terminals IDL and E2 of the sensor ( these are the two lowest terminals when looking at the terminals and when the connector lockdown clip is facing right.
5. Gradually turn the throttle position sensor clockwise until the ohmeter deflects and secure the tps with the two set screws.
6. Recheck the continuity between the terminals IDL and E2 with a couple different thickness gauges. Verify the following:
With .5mm gauge there is continuity between EDL and E2.
With .75 mm gauge there is no continuity.
If step 6 fails, readjust. Its a PITA but the vehicle will run like crap til the tps is in its proper place. HTH.

P.S. I've always had a harder time with this as I basically use both an old meter style multimeter and a new digital style one. I use the old style to see when the ohms deflect and I use the new style to test continuity. How do you watch an ohmmeter deflect with digital multimeters? Thanks.

 

[Rich]

Okay,
How do you watch an ohmmeter deflect with digital multimeters? Thanks.

By using one that includes a bar graph display, like the 15 year old Fluke I use.

Rich

 

[Lars]

Off topic sort of....

I need to replace the TPS in our 2000 4runner. Can I assume the install procedure would be similar? Anyone?

I dont have the FSM for it.


Regards,
Larry

 

[crholliday]

Turbo,

Apply vacuum to the throttle opener tube.

How do you do this? Is there a tool or something for this? I have this picture of my whole body over the engine with my head over the the TB trying to put vacum on that hose with my umm mouth. It would be hard to perform the rest of the steps under those conditions!

Gradually turn the throttle position sensor clockwise until the ohmeter deflects and secure the tps with the two set screws

Is this supposed to be a really accurate kind of adjustment? It must be part art part science.

NOTE TO SELF: Dont detach the TPS during future TB cleaning rounds.

THanks,

C.

 

[turbocruiser]

Turbo,

How do you do this? Is there a tool or something for this? I have this picture of my whole body over the engine with my head over the the TB trying to put vacum on that hose with my umm mouth. It would be hard to perform the rest of the steps under those conditions!

Is this supposed to be a really accurate kind of adjustment? It must be part art part science.
C.

Use a vacuum test tool like a mityvac or something similar. Just put some pounds of vacuum on with the tool and then let the tool just hold the vacuum. Then go on with the repair.

From my experience, yes, it is an extremely accurate adjustment. Someone with a lot more time on tools like Robbie could probably perform procedures like this with his eyes closed but I'm sure he still follows the FSM anyway. Maybe someone knows shortcut, I sure do not. To give you an example, it took me two majorly frustrating hours to get the TPS that is on my 4Runner set perfectly. Until it was perfect the vehicle was practically undrivable. HTH.

 

[turbocruiser]

By using one that includes a bar graph display, like the 15 year old Fluke I use.

Rich

Okay, assuming my multimeter does not have the bar graph display, how do you use a digital multimeter to see when the ohms deflect? I would imagine that if you turn the TPS super slowly and watch the display, you can see a more massive change from one spot to another spot but since the digitals always display some number (other than zero), it is harder to see it deflect than a meter style where you can watch the needle shift all the way to one side. I guess when you see the meter gradually increasing or decreasing ohms at around the same rate for part of the turn, and then a large change at one specific spot, that represents the deflection? Thanks.

 

[turbocruiser]

Off topic sort of....

I need to replace the TPS in our 2000 4runner. Can I assume the install procedure would be similar? Anyone?

I dont have the FSM for it.


Regards,
Larry

The procedure is probably similar...on my 88 Runner the procedure is the same except no vacuum applied IIRC. Still, without knowing the right feeler gauges and voltage and continuity tests, there is no way. HTH.

 

[Scamper]

Okay, assuming my multimeter does not have the bar graph display, how do you use a digital multimeter to see when the ohms deflect?

Not to bust your chops...well then, yeah, just to bust your chops, you can use a 15 year old Fluke 8024B in AC mode (it's a continuity mode for AC or DC)--it has a loud tone that comes on when you have continuity. Comes in handy when you don't want to or can't be watching the meter.