3000 rpm idle.

[DHC6twinotter]

Hey all,

So, I've got everything put back together after replacing a leaking injector, and now I've got an idle at about 3000rpms.

Here is what I fixed before the high idle issue:
-New o-rings on all 6 injectors.
-One used injector.
-One new injector pintle cap.
-New o-rings on fuel rails.
-Fixed vacuum leaks (one of which was on the intake tube going into throttle body)
-New timing belt idler pulley.
-TB and IAC cleaned thoroughly. IAC was very dirty, and probably clogged.
-New radiator
-New thermostat and gasket

So, once all this stuff was fixed, I started up the 4Runner. It ran good, but had the high idle. Here is what I've done to try to solve the high idle:
-Double checked vacuum hoses. All are fine, although I haven't been able to verify whether or not the vacuum lines going to the power steering are backwards or not. Going to do that once I find a good diagram.
-Does not appear to be any vacuum leaks around injectors, or any intake gaskets.
-Turned down the idle screw (the one on top of the throttle body). This brought it down by about 150 rpms or so. It is about 1.5 turns from being screwed all the way in.
-Checked for codes. I do have a code 51, which is for the TPS.
-TPS resistance checked with throttle closed. Resistance was ~1.13 ohms, which appears way off. I've never used a volt meter before, so I'm not sure I did this correctly. Meter dial was set at 20K.
-When I move the throttle linkage on the TB, there seems to be about 1/4 “ of movement before the throttle plate moves.

There was no coolant in the motor while performing these checks.

I know I have a TPS code, but could a bad TPS cause the idle to idle at 3000?

Anyways, any suggestions would be welcome. I’m a newbie when it comes to throttle body adjustments.

Thanks,
Daniel

[DHC6twinotter]

Just an update here....for some reason, the cruise control cable was out of adjustment and would not let the throttle close all the way. It wasn't open much though, and looking into the TB, the difference was hardly noticeable. This may have contributed to the problem, but I doubt it is my main issue.

My battery is dead now, but I'm still trying to figure this out...

I also checked the resistance in the TPS again, and with the fixed cc cable, it is at .77. I think that is within spec????

[slosurfer]

I think a TPS could definately be the problem here. Especially considering the code you are getting. I believe the best way to test it, is to remove it and test it. On 4crawler's site, he has a good writeup on the tps. Sorry, I don't have the link right now. It has some tips and suggestions on it. I know when I did the one on my van, I had to pull the tps to test it. That was a beatch because I had to pull the throttle body to even get to the tps.

[DHC6twinotter]

Thanks Chris. I used 4crawler's instructions, but I'm still a bit confused with how to test the tps. His table shows 500-800ohms for a closed throttle (IIRC), but mine is like 0.77 range. I have the meter set to 20K like the directions said, but I dunno....it seems like maybe the decimal point is in the wrong spot, or maybe my TPS is really messed up. [EDIT: Nevermind, I'm just being dumb. 0.77 (770 ohms) is within spec.]

I lost my fealer gauge, so I've got to buy one on my way in to work today.

Something I don't understand though: Is it possible for the engine to run at 3000rpms with the throttle closed? Does it get enough air? That's what gets me.

[DHC6twinotter]

Also, I'm not sure if my throttle stop screw is set right. The way it is set, the rotating part that holds my throttle cable rotates about 1/8" before it moves the throtte plate. Hard to explain, so maybe I'll take a pic later.

[DHC6twinotter]

So, I've played around with my TPS a bit. I can get the closed throttle and WOT within spec, but the areas that are supposed to be .030 and .020 before the resistance goes to infinite are really about 1/8".

I guess I'll play around with it a bit more. The TPS used to be in the middle of the adjustment range, and now I've got it almost all the way counter-clockwise.

Would I get a code 51 if my TPS is not adjuste correctly, or does a code mean it is toast?

[slosurfer]

Dan, I believe that code could be for an out of adjustment or a bad tps. If I remember right it points to the TPS and then you test the tps to see if it is just out of adjustment or bad. Did you get your new feeler gauges? The fact that you can't get it in specs, kind of makes me think it might be bad, but I honestly don't know much about these.

[DHC6twinotter]

Thanks Chris. I did get new feeler gauges too.

I re-adjusted the TPS, and here are the readings I'm getting:

-Closed throttle: 700 ohms
-WOT: ~5000 ohms (multimeter wouldn't stop fluctuating, but fluctuations were all within spec)
-0.020" 2200 ohms
-0.030" 300 ohms; Goes to infinite at about 0.080" (supposed to be at 0.030", but still ok according to 4crawler's site.)
-No drop outs or crazy fluctuations while going from closed to WOT.

So overall, it seems to be within spec now. Yesterday, I couldn't seem to get it within spec...it seems kinda temperamental. I'm going to plug my TPS in and see if I still get error codes. We'll see how it goes.

It's kinda fun adjusting these, but it took me a bit to figure it out.

[slosurfer]

Dan, sounds like you are on the right track. Don't forget to clear the engine code before plugging it back in.

[DHC6twinotter]

I just put my re-adjusted TPS in, and no more CEL.

I've got to figure out why I have two mystery nuts laying around, and I ran out of light. I'll try to start it tomorrow if the weather holds up.

Chris, I pulled the EFI fuse, and my battery has been disconnected for the past 2 days, so I guess that would clear my codes.