Misfire codes again P0300, P0301, and P0302

[Bob98SR5]

Mike,

Today I had juuust enough time after dinner to remove the throttle and cruise control cables and fired it up after the hose check. Unfortunately the high idle problem is still the same, so we can rule that out.

To check the vac hoses theory, I found a parts diagram from Village Toyota that has a pretty complete set of parts diagrams as compared to other vendors. I checked each and every one of them. All were on there pretty solid, but to your point and my earlier concern, perhaps they are collapsing when in operation. So when I can devote some time, I'm going to put the old hoses back on.

Man I wish I had a smoke tester.

I'm also going to remove the airbox/intake hose assempbly, test/recheck the IACV and throttle body (see below), and take another look at the air hose that attaches to the underside of the IACV.

I did find this interesting post by a YT member who noticed that his butterfly valve was rubbing up against one side from (he presumes) is wear and the effect of the return spring pushing the valve to one side thereby causing it to stick. Interesting observation and fix that seemed to have worked for several people. http://www.yotatech.com/f2/my-high-idle-cured-258318/.

[4x4mike]

I knew I had typed about this at one time: http://www.ultimateyota.com/showthre...4443-High-Idle

This was a post I made after I had taken apart the IACV. I had to take apart the IACV because my 4Runner kept dying upon starting during the Joshua Tree trip years ago. Low idle and dying turned into high idle and I remember after taking the valve off a few times I had finally had it dialed in. All my hoses were fine and I think the problem was using the correct amount of RTV.

[Seanz0rz]

Or just buy the right gasket from Toyota. I have the on around somewhere.

[Bob98SR5]

guys,

I used both a new gasket and RTV. do you think that could be it?

Anyways, today I'm going to check that guy's theory out about the wear and sticking butterfly valve first and then lubing the throttle mechanism. Then hose replacements back to stock hoses.

Mike: thanks for the link. Gonna read up.

[4x4mike]

It's been a long time since I've done the work but I'm pretty sure I didn't omit the gasket or use a gasket and RTV on the same surface. I pretty much followed some write up on YT. IIRC I think the RTV spooged into the mechanism that has the little turny valve, that looks like a pencil sharpener, and kept it from moving or being moved into the correct spots.

[Bob98SR5]

Spooged, lol. Well there is a test (dont have my manual now) where you apply voltage to two terminals and you should be able to hear it click open...or not. Definitely on the list of things to do before taking off the TB and the IACV again. Thanks again for the reply, Mike

[toyotech]

From my experience. If the truck was idling fine before you touched it. Than Chances are it related to something you messed with. If there was a gasket but you switched to RTV. (Hate this stuff). Always go back to a gasket. Silicone can Easily be over applied. Buddy if mine even tho you are suppose to use FIPG to reseal a timing chain cover. He over apply and plugged up oil passages.

[Bob98SR5]

Toyotech: yup, i agree. i buggered something up.


Used the remaining daylight to do a few things:

- Pulled EFI relay for 10 mins and snapped back in
- Gorilla taped one of the hoses I have on order on both ends. Sealed pretty tight. Started it up, still high idle.
- Turned the engine off, got the brake cleaner, restarted the engine, sprayed the hell out of the plenum where the skinny hose could reach. Still the same.
- Tightened down the airbox intake clamps (all of them) and fired up. Same condition.
- Removed the airbox intake and tightened down the bolts and nuts securing the throttle body to the plenum. Same condition.
- Replaced key hoses (not the smallest ones). Same condition. The only one I couldn't do was the hose underneath the plenum that attaches to the throttle body itself (the one under both rad hoses). Same high idle
- Resistance tested the throttle position sensor and the IACV sensors and both are in spec.
- I wanted to see if I bent the hell out of the accelerator cable and the cruise control cable. With both out, the idle was the same as if no cables were attached. I then replaced one on and left the other off. Same high idle at the same rpm. Switch them. Same high idel at the same rpm.

Tomorrow:

- Remove the throttle body (I forgot to bring my angled hose clamp remover and it was getting dark anyways) and apply voltage to the IACV to see if the solenoid actuates the vanes. If not working, I'm going to reseal it again minus the RTV and just use the gasket (assuming its still in good shape). I'm also going to check to see if the butterfly valve is off center.

Question because I'm coming to my wits end: should the butterfly valve itself be perfectly perpendicular to the bore itself? Mine is slightly angled at rest. i believe it should be this way



- Reassemble and try again.

[troyboy162]

Havnt read all the pages but you can't close the throttle further by hand or anything right? Like it's sticking and not closing all the way?

Tps shows like 10% closed?

[Bob98SR5]

troy,

it looks like this: http://www.toyota-4runner.org/attach...p-imag0584.jpg