Suddenly high idle? '90 Celica

I would definitely check the speaker installation to make sure that they are not pushing on the throttle cable.

The oxygen sensor itself probably would not cause the high idle, but if the wire for the sensor is tangled up in the throttle cable under the hood, then the sensor wire could be the cause.

Look at the bell crank on the throttle body to make sure it closes completely.

Check the idle air control valve to make sure it is not stuck in the wide open position.

Check the coolant temp gauge to make sure it is working properly. If it reads cold, that could cause a high idle.

OK, I checked everything. I moved the panel where the speakers were at and tried and the car still ran high. Here is what I found:

There is a vacuum hose loose. I heard this sucking sound on the right side of the engine bay (near the firewall). I found two hoses which were tied together, one seems to be a vacuum hose and the other is not. When I plugged the vacuum hose with my finger, the idle went back to normal and everything seemed to be fine.

Where does this vacuum hose go? What should I do to have it repaired? Any help would be great. Thanks!!

Ray O wrote:

If you have recently done any work under the hood, then look for a disconnected vacuum line connection in the same vicinity. Even if you have not recently done any work under the hood, look for disconnected vacum line connections, especially on the throttle body.

Right of the engine bay from inside the car or standing at the bonnet? And can you provide a photo? Depending on the engine config i could probably tell you where theyre meant to go if you give me some more details. Sounds like you may have something like an air-con idle-up valve connection loose, but any vac hose loose on this car will cause high idle.

OK, it's on the passenger side, near the firewall, within the engine bay. I found three lines actually that were disconnected. One was a larger hose which I cut (the end was split) and re-attached to its port (both ends of the hose seemed to connect to the intake manifold).

The second hose (with the vacuum), I attached to a port in the rear of the intake manifold (there also seemed to be some sort of sensor or other electrical piece where this port was located) that seemed to be exposed. When I attached the hose to this port, the idle went down. However, the idle did not go down as much as it did when I simply placed my thumb over the hole (when I placed my thumb over the hole, the car would idle at about 800rpm, now it is idling at 1000 rpm). ALSO, I can hear a high-pitched noise coming from where I attached the hose (I'm guessing that it is not fully sealed and I was unable to find a way to fully seal it).

There is a third hose (which is being held next to the second hose by some sort of tie) which does nothing. I looked inside the hole at the exposed end and noticed that there may be a piece of metal or something blocking the hose. Right now it is simply hanging where I connected the second hose.

I hope this isn't too confused. If necessary, I could take a few pictures and try and get them posted.

Thanks for your help!!

Coyoteboy wrote:

Must admit im struggling to picture them in my head. Most vac hoses are cut-to-length items so their attachment points will be very close. Also if you look at a chiltons manual, or similar, you should have a vacuum diagram in there which will help identify them. Drop me an email with a couple of pics, via my website,

or postthem in my forum for me to browse.

I sent you a message via the contact form on your website. Hope it'll get to you. If not, here is what was sent:

---CLIP------CLIP--- I took a picture of the area where I re-connected the vacuum lines, on the passenger-side rear of the intake manifold. The line that is circled, that is the one that seemed to have come loose and is making the high-pitched noise. Running next to this vacuum hose was the hose that featured a connector that seemed to be blocked (instead of it having a hole, it had a piece of metal sealing it shut).

URL for the pic:

As I said earlier, when I completely plugged the vacuum line with my thumb, the car idled "perfectly." With it connected to the intake manifold, it makes a high-pitched noise and the car seems to idle about

200rpm faster (from 800 to 1000).

I tried to find the vacuum diagrams in my Chilton's but was unable to find them. I'll try flipping through the pages again to find 'em.

Thanks!!

---CLIP------CLIP---

Coyoteboy wrote:

For my Nissan, I found that the Chilton's vacuum and wiring diagrams were inaccurate, the wiring diagram grossly so, while the diagrams in the Mitchell manual (libraries have them, in print, CD-ROM, or on-line) were accurate.

For my Nissan, I found that the Chilton's vacuum and wiring diagrams were inaccurate, the wiring diagram grossly so, while the diagrams in the Mitchell manual (libraries have them, in print, CD-ROM, or on-line) were accurate.

Yes, I did find the vacuum diagrams in my Chilton's manual and like you, they were inaccurate. Figures, the two hoses that I was questioning are not in the diagrams (shows three hoses when there is at least five).

I used some teflon (plumber's) tape and wrapped it around the outlet for the hose on the intake manifold. This seems to have helped SLIGHTLY.

I have to admit im not familiar with the engine so i cant give you definitive answers on that :( Sorry!

Vacuum hose usually is sold by the foot in bulk. Save the old connector and use it on the replacement hose.

if its original equipment a toyota dealer will be able to order it in. (although they have stopped making some body panels, so if you need any soon buy them now lol)