RylerTust

My idle keeps dropping. Can't figure it out. Tps is new and in spec. Never over heats. Temp is perfect. Checked with ir thermometer. Can't find any intake leaks. The intake boots cracked but I wrapped it with this stuff that's supposed to seal it. It doesn't leak now. But I get a random drop in idle that's real low. Almost to 300rpm sometimes. Did it bad last night.
Woke up and burped my cooling system to be sure. Refreshed my ignition grounds cause i can hear the crackle in my radio. When it was idling I noticed my oil dipstick was kinda rattling around. Pulled it out and idle dropped like it did before. Wrapped a layer of electrical tape around the rubber seal to make it actually seal(only temporary) and idle raised to 1k rpm.

So my main question is if the oil dipstick seal is loose enough can it cause the idle to drop and even run lean??
I know it idles lean cause I have a wide band o2 gauge and sometimes idle will run at ~18.5:1 air/fuel ratio when it should be 14.7:1.

Any ideas? Thanks yotatech!
Tyler

osv

the dipstick tube does need to be sealed tight... you can try using shrink wrap on the upper rubber end, until you can get another one.

you could also try covering the idle screw top area with rtv, as a temporary measure, to see if the o-ring is leaking.

RylerTust

I replaced o rings on the idle screw and idle up screw last week.

I can't find any loose wires or broken wires anywhere. The engine bay in this runner are very well kept.

Btw it's a 1990
4runner
22re
5 speed