Hey guys
looking for a little reassurance here on which sensor is causing my ever so much hated high idle problem, has been going on for months, finally getting sick of the wasted fuel

here goes, 91 4runner 3VZE Auto
background of problem.. a couple months back i blew my coolant transfer line.. that really ignorant on under the intake mani just in front of the firewall, anyways i know right next to it is my coolant temp sending unit, my coolant temp senor and cold start sensor.. i think the exploded cooling line cooked either my coolant temp sensor or cold start sensor as the truck constantly runs "cold" it seem, you can smell the wasted fuel being dumped into the cylinders, and once and a while after a really good drive on the highway and let her sit for 5 or 10 min start back up she will idle fine for a small while

also just recent last couple of days as weather is getting cooler, she is starting to flood herself out and wont start right off the get go like she usually do

what do you guys figure..or any other ideas? thanks mucho!

 

Well grab your ohm meter and start testing sensors.

Use the 1993 FSM posted in the FSM sticky to get the specifics, but test:

- Coolant temp sensor
- TPS
- Vafm
- o2 sensor

I have tested all but the Coolant temp sensor (thats next), the rest are VERY easy to do. The TPS can be a pita to adjust, the screws are tiny and you cannot get any leverage on them.

You should remove the throttle body anyways and bench test the TPS, I couldnt figure out a way to get thickness guages between the stop screw with the TB installed..

 

Jump the terminals between TE1+E1 on the test connector under the hood,
If there is a prob with the temp. sensor or any other sensor it will usually show up .then you turn the ignition to the on position and count the flashes.You'll need a manual to know
what the flashes mean..

Of course this might only work if there are stored codes.

 

I have heard of ALOT of situations where the computer has not thrown a code and some of the parts mentioned were failing.

Test the resistance on the parts I listed. It should only take you an hour or two... very easy.

 

Yup that does happen .

 

yeah, my truck has yet to trip any codes, have definatly checked that a couple times.. even threw a code reader on her today to triple check, to try and save the headache haha.. no luck.. i even went as far as taking her into a shop yesterday.. haha.. and as luck would have it for the mechanics.. she idels PERFECT took for long hard drive.. still PERFECT and of course today.. runnin like crap haha.. guess time to start checking, but thanks guys.. just wanted to see what everyone else thought before i start squishing my arms down in there to test everything

one other question though.. someone has suggested possible leaks from intake mani, anyway to test for this? have tested for vacuum leaks could not find any though

 

check the connectors to all of those sensors and clean them all with electrical contact cleaner
coolant can conduct electricity even when it appears to have dried.