hello all you toyota techs out there!!!!!!! Got myself a brain buster here. My 3.slow at 90K al of the sudden got a little shake at idle,not much noticable at cold start but as the rpms drop, it shakes moderately in idle but when i start to open the throtle it starts to shake more to a mifire condition and at 2000 rpms it all smooth. Checked all the standard things all seem to check ok. Have a fuel air guage and during that idle to 2k rpms guage reads lean, no codes on ecm. tomorow will chek pcv hose and valve and will do a compressin test. Plugs tips look white which definetly steers me to a lean condtion. But why? Vacuum leak!!! where, cant see one or maye some one knows of common areas to look ?. Help !!!!!!

 

a vacuum leak could cause what you experience. also, the coolant temp sensor can, as well as a faulty/maladjusted throttle position sensor.

 

Ok, did a compression test and am getting 160 dead even on every cylinder, what i did was use a fuel injection cleaner, added to a 3/4 tank of gas and ran it till tank was empty, major improvement, almost perfect. I also forgot to mention another condition that is happening during cold starts thats been going on for a while now. When i start it in the morning and start driving, I watch the temp guage. When it gets to about a 1/4 the truck kind of stumbles when i give it gas, then i give it more gas and the truck picks up fine and then it seems to run ok.