High idle, need help!

ahh, I see. Cool that's good to know, I'll add it to the list

 

I did that same thing on half the side when a post snapped. The truck doesn't like it.
Never got a good seal.

 

what was happening with your truck? high idle?

 

This guy seams to have a similar problem and he diagnosed it as the thermostat needing to be replaced: https://www.youtube.com/watch?v=A5d-aCpn-f0

 

No high idle with that one.
O2 codes constantly popping up with check engine light on. Even after resets and a new sensor.
If the truck was driven for any 30 mile+ distance and shut off, I would have to let it cool down before attempting and hoping it would start. Always did and I drove it from WI to CO and back that way. (was is my early 20's)
O2 sensor was getting incorrect readings because of the bad seal.
A tiny hole in your exhaust and/or a bad cat could have the same affect on it. For future reference.

 

True, yeah he took it off and cleaned it, and when I asked him about the butterfly flap he said it was fine, but I doubt he put a light up to it like you did

 

Maxbore would be the go to resource if you want to get the throttle body / butterfly valve serviced. I know you're hoping for a smoking gun here, but ya gotta fix the system as whole. That exhaust "fix" might be the cause of your problem.

 

I need that scan data he's using.
Makes sense and worked for them.
Thermostat is fairly cheap part but can be a pita to change.
What I'm not following from the video is he said the throttle stop was all the way back and it was 'fully closed' but idle was still high?

 

Yeah I totally get what you're saying, but the exhaust "fix" was like 6-12 months ago, and the idle is only a recent issue. Also, I only "fixed" the exhaust because I could hear a rattle in neutral, it wasn't giving me a check engine light or anything. I really don't think that it is causing any problems, but I will mention it to the dealer when I drop it off.

I'm not very mechanically inclined so I don't want to go in there and make things worse, especially since the last shop said they would be open to refunding me if it turns out to be something simple, or the IAC (which they replaced).

 

Toyota is going to start at the same place we all are- solve the simple problems and work up to the harder more expensive ones. While you've made your point clear that you don't believe the exhaust is a factor, the reality is the WHOLE system has to work right. Invalid exhaust readings, whether they throw a code or not, ARE a factor in the idle. It's actually worse if you don't have codes, and there is an exhaust leak- It means the ECU is using BAD data to adjust the A/F and idle.

The exhaust fix is extremely low hanging fruit to correct. Next they're going to replace the IAC with a OEM part- they aren't going to screw around with diagnosing aftermarket parts.

Then probably onto vacuum and (other) exhaust leaks. With the very high idle you have (high idles are 1000rpm), it's likely a vacuum leak, improperly adjusted throttle cable (my bet is still this), or faulty ECU.

 

Appreciate the reply, and understand what you're saying. I'll have another look at the seal on the 02 sensor (for what it's worth, it's the one behind the cat closer to the rear). Vacuum leaks and throttle cable have been ruled out.

Damn, I really hope I don't have to buy another IAC, but I guess if I do, I'll get the other shop to refund me for the one they put in.

 

Update, dealer says the throttle body butterfly flap is worn out, so to replace. But that they don't make OEM throttle bodies anymore, any leads on where I can find an aftermarket one, or shops that rebuild throttle bodies. They also said it could be the ECU (which they also don't make any more) , but that it's more likely to be the throttle body. Anyone have any experience getting it rebored from Maxbore?

 

The one I see mentioned on here alot is https://www.maxbore.com/

 

Found a throttle body local to me off a 98 4runner, same year. Will it matter if it's auto or manual, or will it be the same? (mine is manual for reference). Also does it matter if it has cruise control or not?

 

Update. Hopefully this thread is useful to someone else someday.

Swapped in a 98 runner throttle body, and now my idle has dropped down to 850/900, which is much better. However, the throttle cables aren't lining up (one is an inch too long/too much slack, the other is an inch too short, not enough cable. so I can't drive my truck. Since, I've narrowed it down to the TB, I'm gonna send my old one to Maxbore and have him fix it. However, when looking at the gap on the butterfly valve, they are actually still very similar. See pics

Old TB


Swapped 4runner TB:


4runner TB on left, which idles fine, original TB on the right, idles like shit but visually looks in better condition



Throttle cable issues:

 

Update. Problem solved. Got the re-bored TB back from maxbore, he did an excellent job.

Be careful when you ship stuff to him, I didnt pack my TB properly and the TPS sensor broke, don't use bubble wrap like I did, it will pop.

George did a really good job with the Re-bore and my TB looks new again. He also added some kind of washer so the butterfly flap won't wear out again.



Noticed some oil in here before I put the new TB back in, hopefully this is normal?

 

Nice.

Yea it's normal to have a small amount of oil in the intake due to PCV gases condensing in the intake.

 

That's a good looking rebuild job, kuddos to that craftsman.