Unwanted acceleration, high idle

[Bennyhonda]

I thought I'd run this by you guys.

1990 Camry LE V6 Automatic.

Symptoms:

• The car is always speeding up on the highway, even if gas is let off. I find myself using the brakes way too often.
• Idle is high, either in park, or when shifted into N while driving. It will idle anywhere from 2-4k. Sometimes it will slowly return to below 1k, other times I am forced to floor the gas and let off quickly for it to return to normal.
• I have also visually confirmed that the throttle body was getting stuck open.

Previously Attempted:

• Cleaning the throttle body assembly inside and out with carb cleaner.
• Manually moving throttle linkage cables.
• Cleaning the cables and cams near the vacuum actuator.

The problem went away for a day after all this but it's back.

I'm left to think it's a vacuum leak/blockage or malfunction with the vacuum actuator itself or perhaps a bad return spring on the pivot cams for the linkage cables.

Any suggestions would be greatly appreciated.


Ben B
Portland, OR

[Bennyhonda]

I may have found the problem today. While exploring the vacuum tubes, I noticed the throttle cable was bent at a 45 degree angle at the attachment point to the vacuum actuator. Pulling back the rubber I was able to see the plastic protective shroud is halfway cracked around the diameter, allowing one to see the cable inside. I was able to reroute the cable to get the kink out and slid the secondary shroud (to protect from bending, a lot of good it did) back over the top. I'll let you know how it goes after a few days of testing.


Ben

[TBayToyotaBoy]

My 1990 V6 does the same thing routinely, but it only sticks at 1500-2000rpm...every two months or so I clean the TB, and remove/clean the ISC to ensure it doesn't stick open.

I have a TB from a low mileage ES250 (150K km) and I'm going to be installing it when the semester's over--my TB is just worn-out.

[marc780]

Pulling back the rubber I was able to see the plastic protective shroud is halfway cracked around the diameter, allowing one to see the cable inside. I was able to reroute the cable to get the kink out and slid the secondary shroud (to protect from bending, a lot of good it did) back over the top. I'll let you know how it goes after a few days of testing.

I think i'd not mess with it, try to lube it or fix it, etc. just change this cable right away. A new cable costs money but nothingcompared to a lawsuit - A Sticking throttle is DANGEROUS

My 1990 V6 does the same thing routinely, but it only sticks at 1500-2000rpm...every two months or so I clean the TB, and remove/clean the ISC to ensure it doesn't stick open.

your engine has a little too much blowby which is really no big deal as long as the compression is ok and you can pass smog (even brand new engines have some blow by). But i read here some people just splice in a cheap, clear plastic fuel filter into the pcv hose that goes to the plenum. The purpose of doing this to catch the oil vapors, or most of them anyway. Then you might not have to clean in there so often.

[TBayToyotaBoy]

Yeah, I had forgotten about that filter idea. I saw a post on that last year, I think. It's such a quick, cheap fix...maybe I'll do that until I get the new ES250 engine in the Camry next spring.

Luckily the stickyt throttle isn't as problematic for me in my 5-speed. No lawsuits, that is!