91_TOYOTA_4x4

So my friend bought a 91 2dr 4runner and he is having these weird things happening ( what else is new). So this is whats happening- basicaly he will be driving it and it will idle down to 250 300 RPM (how is it running) sounds like a honda dirtbike. anyways then the temp jumps to the red?? then it goes to normal. this has happen like 3 times and it seems to pull ok and run fine other wise. So anyway we think its over heating ( not suprising for a 3.0L). So he is getting anoyed and is loosing interest in his awesome 4runner ( that i want lol) and im i have been trying to convince him to hold on to er. If we could fix this it would be awesome!! rightnow we are thinking to go 3.4 hehe but he needs the 3.0L to hold on untill school is out in the summer so any imput would be great! thanks guys!

Jay351

Make sure there are no rips in the intake or vac leaks.

Cooling system in good shape? Hows the fan clutch?

Does it only overheat when it idles low? Perhaps the waterpump isnt spinning fast enough to get the coolant flowing, or the fan is not spinning fast enough to cool the coolant...

85excab

sounds like the ecu going wacko
check the ground on the ecu, and has it been submerged in water?

91_TOYOTA_4x4

well he has never submurged it before and we are going to check that ground on the ecu. The guy who had it before duct taped the intake tube going into the throttle body? prob because it broke so no that you mention it that could be the prob. How it has happend to him 2 times on the highway, he will be cruzing then traffic gets bad and he will be idleing alot and then all the sudden it drops down and the heat goes up. so he gets moving again and the temp jumps to normal and it idles fine again. We drove up to 100 mile house from langley ( about 500 Km to our cabin) and his runner was getting hot a couple times while my 22re was nice and cool and doing about the same on the hills as him. so im going to get him to get a new intake tube and check the ground on the ecu. thanks guys!

Jay351

If a ripped intake is letting unmetered air into the motor, its going to run lean and thus hotter..

Make a ISR tube for him Easy stuff for the v6.

Should be very hard to overheat a 3vze thats in good shape. They have big rads, my clutch fan never has to really kick in!

91_TOYOTA_4x4

yah his seems strong for a 3L and dosent burn any oil so thats got to be the reason. we knew of the duct tape but didnt think that could be it haha. ill let you know how it goes. thats funny about the clutch fan because his barly licls in but this whole summer around town my fan was on the most the time (22re).

Jay351

Yeah, I notice my girlfriends 22re 4runner's fan clutch kicks in often when its hot outside.

My fan clutch NEVER kicks in, I even swapped it with another in perfect shape and it still never kicks in

If his truck was really overheating I would check the fan clutch. It could be worn out.
Get the truck warm, turn it off and try to spin the fan. You shouldnt be able to spin it very far, like half a rotation.

91_TOYOTA_4x4

Ok will do. We also think the rad has a very tiny leak because he has had to add a bit of coolant here and there. we are planning to go to stave lake tomorrow or sunday so we will see how she goes then. oyah hes got pavment pounding 31's haha should be fun.