Throttle position sensor question

I don't think that's normal. You might need to get your throttle body re-bored. @1997tacomav6 has some info on doing that.

Over the years the butterfly valve can wear grooves into the throttle body if not adjusted properly. When you clean it you remove the grime that was filling those grooves and now there's more air being let through. Would explain the rough idle not going away

 

Why did you replace the TPS in the first place? Same symptom?
IF the high idle occurred only after replacing the TPS then I would not worry about the light around the butterfly. Do you have your TPS readings before and after the replacement? Have you cleared the codes or at least disconnect the neg battery terminal after the fix? Also, what is the current code from the CEL?
If you're doing all this w/o a scan tool you're flying half blind.

 

Another thing...when you took apart and reinstalled the throttle body, was the gasket that goes between the throttle body and intake manifold in good shape still? If it was the original one and was falling apart that could be creating a vacuum leak which would give you similar issues to what you describe.

Usually that gasket gets replaced when the TB gets taken off. The OEM one is cheap

 

That’s your problem the butterfly and or the walls on the throttle body are worn and there is an air gap
that is causing the problem, cleaning it has removed all the carbon that was holding the gap closed.

You have to send it to maxbore at 125.00 to fix it and a good two week to get it done, 1st come 1st served .

It should look like this, he did mine

 

You could try backing the idle screw out a little.

 

When I cleaned my throttle body the first time , I used a zip tie where the throttle cables attache to hold the throttle plate open. I did that to make it easier to clean but now I’m wondering if doing so made the

There wasn’t that much carbon that I saw..

I’m really hoping I don’t have to have it send it off.

 

I may try that.

 

Because of the air gap it’s letting air get past the butterfly which means the engine will
idle higher. Sooner or later it will have to be addressed.
You might be able to hold that off by adjusting the idle screw if you have the earlier throttle body assembly.
Regardless your throttle body did NOT come from the factory with that air gap shown. This section is worn

 

If you have a decent phone you can get a Bluetooth or WiFi ODB II scanner with an app that can tell you more information to make the diagnosis more accurate since throttle position and (obviously) CEL codes can be seen. The throttle position should be 9-12% at idle - if the number is off then at least you’ll know the sensor / ecu aren’t doing the right thing. If it’s reading the right number but still idling high you’d probably have more air passing through the IAC or butterfly valve.

 

I remember reading about someone having a similar issue and with had to do with the linkage not allowing it to close all the way. That had to put a shim on along one side of the linkage.

 

https://www.tacomaworld.com/threads...-idle-post-tune-up.364310/page-3#post-9964827

 

How can you tell if it’s an older model throttle body?

 

You have the throttle by wire and the throttle body with a cable to the butterfly

 

If you don't have this extra connection on your throttle body it's the older type.

The drive by wire on the 2003 and 2004 still have a throttle cable.

 

Soo.. The 2nd time I removed my throttle body to check everything my battery was disconnected for about 2 hours.
When I finished I started the truck and it still idled high but now also ran VERY rough for the first few miles of driving, but then smoothed our. I sort of expected this because a lot of posts on TW say that the computer needs to re-learn a few things after the battery is disconnected for a long time. But now, 3 days later, it still runs pretty rough after a cold start. The check engine light came on today so I had Oreilley’s run a diagnostic and this was the result..


Holy shit that’s a lot of codes!!
I’ve had to drive the truck every day because it’s my dd, can anyone help me understand this? I really hope I didn’t make things worse by driving it.

 

It's only one code but a list of possibilities.
Check all the electrical connections in that area.

 

You only have two codes: P0300 & P0306 - both having to do w/ misfires. The first, random misfire and the second is a misfire on cylinder #6. Both of these would be unrelated to your RPM issue but are definitely related to your rough running problem.

 

I'd start by inspecting your wires. Make sure they're all in their holders and not dangling around somewhere where they could have rubbed through or melted. After that check for spark on #6 w/ a spark tester.

The fact that it gets better when warmed up could spell bad news but alternatively the fact that this happened right after you were in there could be that something just got messed up by accident.

 

Ok folks! Update.. hopefully this will help someone having the same problem.

I have replaced...

- Spark plugs (ngk dual electrode platinum)
- All 3 ignition coils!! (New Denso Original oem)
- Ignition wires (ngk oem style replacement)

While trying to removing the spark plugs, the connector that slide onto the tip of the spark broke off!
Now I can’t get my 2.5” long spark plug socket down enough to remove it because there’s a metal wire fitting sticking out the end.

I suppose that would explain the error codes!
Two spark plug wires corroded enough to break off upon removal!

Fun stuff! But at least I know there was something obviously wrong!!

 

Grab it with long needle nose pliers.