why is my 2003 tacoma idle high and slack in throttle line, after I replaced the throttle body?


Asked by Jul 13, 2013 at 07:17 PM about the 2003 Toyota Tacoma

Question type: Maintenance & Repair

42 Answers

....well high idle can be attributed to the vacuum hose removed at the pressure regulator~ should have taken pictures because you missed a clamp...perhaps holdin' her steady capn' for the entry to the business end...this one still has a cable? thought they were all drive-by-wire anymore at this point in automotive history~

4 of 4 people found this helpful.

No vacuum leaks. Its doing the same thing it was doing before I put the new throttle body on. When I disconnect a battery cable and reconnect, it runs fine, with no play in throttle. But when I shut the engine off and restart, it idles high and play/slack is back in the throttle. Please help!!!

11 of 11 people found this helpful.

does this one have a 'thermo-time switch?'....will investigate~

1 of 1 people found this helpful.

okay no...I guess...robot keeps coming up with temperature sensor as it's solution...do we believe the friendly robot?

1 of 1 people found this helpful.

the ambient air conditions tell the ECU how much to enrich the air/fuel mix...perhaps this device is not working properly~

1 of 1 people found this helpful.

I trust you got the slack out by putting the bushings in there out of the kit if there was one or clamping correctly in the right spots?


No sir, the slack is in the new throttle body. All of them have it. Someone mentioned that it has to relearn. I've tried everything. Do you think a sensor is bad?

1 of 1 people found this helpful.


5 of 5 people found this helpful.


1 of 1 people found this helpful.

Faulty throttle position sensor could cause this type of issue. Also appears in your picture that you might have a vacuum line missing.

2 of 2 people found this helpful.

The TPS came on the new throttle body. Which vacuum line is missing?

the somewhat larger vacuum hose coming out of the filter box is cracked at the exit of the filter box...replace cracked butyl rubber with silicone---not quite sure which line dandyoun things isn't there....aside from the visibly cracked butyl rubber hose am going to have to study the pic...

hey....there is an adjustment right there to take out the slack~

3 of 3 people found this helpful.

I will replace the hose and continue to search for a soloution to the high idle and slack in throttle.

the exit barrel the tps is activated has a screw thread for taking out any extra play....did you not see that one?


No sir.

okay in your first "photo' the adjustment looks cheesed off, in your second photo it looks like there is at least ten MM of adjustment...is there no adjustment and the cable looks ragged like in the first Photo?

1 of 1 people found this helpful.

Hey Judge, the slack is in the throttle on the throttle body, not the cable. When I reset by disconnecting the battery cable and reconnecting, the slack goes away, and everything operates fine. But when I shut the vehicle off and restart it, it idles high and slack is back in the throttle. When this happens, the vehicle changes out rought.

there isn't a rotary adjustment on that TPS?...you sure?


I'll send you a photo of the TPS.

1 of 1 people found this helpful.

This is the top of the TPS.

1 of 1 people found this helpful.

Photo 2

1 of 1 people found this helpful.

looks like your ears are in a fixed position...some have crescent slots that allow you to zone in on the correct location....do you have the correct replacement unit?

1 of 1 people found this helpful.

This is just like my TBS.

1 of 1 people found this helpful.

guess you know what needs to be done now~


What's the process? Loosen both screws and rotate clockwise? Please give me step by step.

3 of 3 people found this helpful.

I imagine you are sleepy, therefore, tomorrow will be fine.

2 of 2 people found this helpful.

well perhaps with the motor running, loosen till still gripping slightly, then rotate until it "feels right"...I mean I could do some research to find voltages and amperages and such, but would need to study the schematic...it is actually a beautiful night here in Clearlake...today got over 95 degrees but a big L is takin' over and I'm enjoying every minute of it~...makes me want to make another pot of coffee---~

bet it's going to be the point at which it starts to affect the cable...that would be the "sweet spot"~ goodnight my friend~

someone put yellow 'caution' paint on that...so you could put it back the way it was? there has to be a good reason....

hell with their paint...it has to be tuned properly~


Thank you, Judge_Roy!!! I will give you an update tomorrow evening.

to ask your prior inquiry about the vacuum line, I was talking about your fuel pressure regulator that if the line gets cracked or falls off the engine will be pullin' vacuum and not letting full flow of gasoline...a one two punch and will not be detected by your onboard diagnostics OBD-II~


After I make the adjustments, does the system need to relearn?

You know I've never had any system ask to have space to "relearn" the sensors are there...the parameters are all preset...really not sure of where this "relearn" business came from...I mean if you are swapping out ECU units for example may take some time to learn the new parameters but honestly, turn the tps until you are comfortable with it (probably JUST out of the slack that may be there) and cinch it down~ if it is not running right...we will have to consult the OBD-II diagnostics then~

....speaking of idle speed, you've got an idle air control valve that may or may not be actin' right~


Well Judge, no luck. Doing the same damn thing!!! This is a brand new throttle body.

1 of 1 people found this helpful.

THE IAC (idle air control) is messin' up~....noted above, perhaps you could get a cheap second from pickNpull~

1 of 1 people found this helpful.

Where is it located on the vehicle?

3 of 3 people found this helpful.

It has been a pleasure workin' with you jtubbs, all I can say is we climbed through the planes of hell together...hopefully the IAC will make it all worthwhile~

will find a cartoon~

okay slapped to the bottom of your throttle body~

Your Answer

Add photo

Related Questions


Looking for a Used Tacoma in your area?

CarGurus has 42,384 nationwide Tacoma listings starting at $1,995.


Search Toyota Tacoma Questions

Toyota Tacoma Experts

#1 Tom Demyan
Tom Demyan
Reputation 1,020
#2 genxer36
Reputation 340
#3 BURT100
Reputation 330
View All

Related Models For Sale

Used Toyota Tundra
440 Great Deals out of 34,876 listings starting at $1,991
Used Nissan Frontier
295 Great Deals out of 22,961 listings starting at $1,795
Used Ford F-150
2,067 Great Deals out of 208,410 listings starting at $290
Used Toyota 4Runner
272 Great Deals out of 19,096 listings starting at $2,695
Used Chevrolet Silverado 1500
1,839 Great Deals out of 182,569 listings starting at $1,595
Used Chevrolet Colorado
249 Great Deals out of 25,762 listings starting at $1,000
Used GMC Sierra 1500
783 Great Deals out of 70,049 listings starting at $1,550
Used Ford Ranger
178 Great Deals out of 5,692 listings starting at $950
Used Jeep Wrangler
269 Great Deals out of 16,406 listings starting at $2,695
Used Dodge Ram 1500
438 Great Deals out of 10,939 listings starting at $1,000
Used GMC Canyon
96 Great Deals out of 11,177 listings starting at $1,995
Used Nissan Titan
187 Great Deals out of 19,181 listings starting at $1,500
Used Toyota Camry
1,116 Great Deals out of 91,351 listings starting at $1,222

Used Cars For Sale

2017 Toyota Tacoma For Sale
21 Great Deals out of 25,065 listings starting at $14,995
2016 Toyota Tacoma For Sale
64 Great Deals out of 2,640 listings starting at $20,281
2015 Toyota Tacoma For Sale
70 Great Deals out of 2,971 listings starting at $16,384
2014 Toyota Tacoma For Sale
45 Great Deals out of 1,959 listings starting at $8,850
2013 Toyota Tacoma For Sale
52 Great Deals out of 2,066 listings starting at $7,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.