99 Tacoma pickup idle problem

Hello all, first time posting here.

I have a 1999 Toyota Tacoma pickup, 5 speed stick 4 cylinder. When I first start it up it runs at a lower idle than it should. But as soon as it warms up just a bit the idle goes to about 12-15K rpm. Also, when it sits during the day and it’s warm outside it will start up with the fast idle.

I don’t know if this is coincidence or not but, I found a rabbit sleeping under the hood during the winter (this has been going on for a while). The rabbit chewed through a vacuum hose and a spark plug wire. The vacuum hose was split right by the fitting so I just cut off the 1 1/2" of tubing and re-attached it. The spark plug wire I didn’t know was damaged until I drove it for about 5 miles or so when I finally got out to see why it was still running bad. I then had to drive another 5 or so miles to the auto parts store to replace it. I have replaced all the spark plug wires just to be sure.

Anyone know what this would be?


You may as well change all the other vacuum lines too (one by one so they don’t get crossed).

I’d also suggest cleaning the mechanical portions of the throttle. There may just be bunny fur clogged up in them.
And check the wires on the temp sensor. Mr. Bunny may have chewed them half through.

thanks tsm, I’ll check those.

anyone else think of anything?

Had the same problem happen to my 95 Tacoma truck after it sat for over a year while I was doing body work on it. It was stuck/gum up throttle plate. Just take the intake off and try to clean the throttle plate and intake manifold as much as possible. Rabbit hair would do it.

I’ve had this same problem but mine is a bit deeper. Bought my 99 tacoma 4 cyl in KY around July and it worked great for about 4-5 months, replaced most of the vacuum lines because a few were cracking, and it ran fine.
Started getting this problem towards fall, and after noticing it and replacing the fuel filter to no effect, I ended up replacing the throttle body, and that solved the problem for only another 2 months, but it has returned.
I’ve found out pouring an entire can of seafoam fuel cleaner only solves this issue for a few days, or a little over half a tank, but nothing else works. Most of the people I’ve asked about it just say that the fuel nowadays isn’t what its used to.

As an edit, I own a '99 2.7L automatic, (great truck), and after buying it I moved down to Georgia.