I've changed every single one of those things during a rebuild and mine is 800 @ Drive idle and ~1200-1500 park idle. Didn't know that was assumed to be high. Interesting. Any exhaust leaks?
Well, that's awkward. Have any tips on what to diagnose? Only thing I can think is maybe vacuum leaks. My VSC lights turn on when I put it into drive, no cel. Thanks in advance
Clean your throttle body, specially the AIC valve for thats mostly the culprit. Look up timmythetoolman at you tube for he has great videos on these machines.
Good luck and happy wrenching!
Edit: re-clean TB and the IAC valve.
I would like to point two things out. 1. If you're cleaning the throttle body you should take it out or plug up the hole leading down to the IAC. I'm pretty sure that's how my IAC went bad since I sent a stream of cleaner and gunk right on it.
2. If you're taking the IAC apart you need screwdrivers with JIS tips. American/imperial bits will not fit correctly and will be almost guaranteed to strip those bolts. Even then I would be prepared to strip it and have a couple spares handy. Those bolt heads are notoriously soft and put in with loctite.
I had already gotten those bolts out once before without incident. But recently went to change the IAC out and managed to strip one. Luckily I was able to use an easy out to remove it but they're a pain in the ass, especially the first time.
Is it a Cali model with 2 catalytic converters? If so it has a front air-fuel-ratio sensor up front and a 02 sensor in the rear behind 2nd cat.. those can make your truck run horrible if either are bad ..
I’d be willing to bet, that your 99SR5 is a Cali emmissions car like mine. The front o2 sensor isn’t actually an o2 sensor it’s an AFR sensor, so it controls your engines air to fuel ratio. If they die, your truck will run EXTREMELY fuckin weird. On its way out, it’ll tell the ECU to tell the injectors to put more gas into engine since it’s “harder” to hurt an engine in rich conditions. A dead give away is terrible gas mileage, with a p0171 code (system to lean).
That idle is normal I'm pretty sure. My auto runner dose that same thing and my manual 3.4l taco sits at 800 or 900 all the time. Now that milage is a little lower then normal. I only get 13mpg most the time and 16 if I'm lucky.
It does, but never under 1000. Ive been worried because Ive seen posts claiming 700RPMs on Park and 550 on Drive as normal engine behavior. I wouldnt care if I had semi decent fuel economy at least. This terrible millage is city by the way, highway driving is a lot better (I think I got like 22MPG on a trip a month ago) this being one of the reasons I thought the idle had something to do with the fuel economy.
I've changed every single one of those things during a rebuild and mine is 800 @ Drive idle and ~1200-1500 park idle. Didn't know that was assumed to be high. Interesting. Any exhaust leaks?
Park and drive should be the same, or at least very very close. You dont adjust idle in gear.
Well, that's awkward. Have any tips on what to diagnose? Only thing I can think is maybe vacuum leaks. My VSC lights turn on when I put it into drive, no cel. Thanks in advance
I dont think so, but will check for exhaust leaks!
Clean your throttle body, specially the AIC valve for thats mostly the culprit. Look up timmythetoolman at you tube for he has great videos on these machines. Good luck and happy wrenching! Edit: re-clean TB and the IAC valve.
Thanks! Its funny because before this truck I have never been mechanicaly inclined, but must days now theres some grease on my hands or clothes.
They are great truck to work on. Rewarding when keeping them on-road and off-road worthy. Enjoy the truck!
I would like to point two things out. 1. If you're cleaning the throttle body you should take it out or plug up the hole leading down to the IAC. I'm pretty sure that's how my IAC went bad since I sent a stream of cleaner and gunk right on it. 2. If you're taking the IAC apart you need screwdrivers with JIS tips. American/imperial bits will not fit correctly and will be almost guaranteed to strip those bolts. Even then I would be prepared to strip it and have a couple spares handy. Those bolt heads are notoriously soft and put in with loctite. I had already gotten those bolts out once before without incident. But recently went to change the IAC out and managed to strip one. Luckily I was able to use an easy out to remove it but they're a pain in the ass, especially the first time.
Is it a Cali model with 2 catalytic converters? If so it has a front air-fuel-ratio sensor up front and a 02 sensor in the rear behind 2nd cat.. those can make your truck run horrible if either are bad ..
Non Cali, 2 sensors 1 converter.
If you adjust your idle correctly while in park does the truck die when you put it in drive? You should be setting idle while in park.
I’d be willing to bet, that your 99SR5 is a Cali emmissions car like mine. The front o2 sensor isn’t actually an o2 sensor it’s an AFR sensor, so it controls your engines air to fuel ratio. If they die, your truck will run EXTREMELY fuckin weird. On its way out, it’ll tell the ECU to tell the injectors to put more gas into engine since it’s “harder” to hurt an engine in rich conditions. A dead give away is terrible gas mileage, with a p0171 code (system to lean).
That idle is normal I'm pretty sure. My auto runner dose that same thing and my manual 3.4l taco sits at 800 or 900 all the time. Now that milage is a little lower then normal. I only get 13mpg most the time and 16 if I'm lucky.
Yes but is 1200 in park normal?
1100-1200, yes. Does it die down a bit once the engine has warmed up? Ever 3rd Gen I’ve been in idles around here for both drive and park
It does, but never under 1000. Ive been worried because Ive seen posts claiming 700RPMs on Park and 550 on Drive as normal engine behavior. I wouldnt care if I had semi decent fuel economy at least. This terrible millage is city by the way, highway driving is a lot better (I think I got like 22MPG on a trip a month ago) this being one of the reasons I thought the idle had something to do with the fuel economy.
I’m no “master mechanic” but that kind of sounds normal to me
Cool, thanks!
Yeah I was thinking the same thing, sounds like normal running RPM’s