dirtyXplorer

Hi all,

Recently, I have been having issues with my stock tach. Its a 1993, 4runner, V6, auto, 4x4. I have done some searching but have not found similar problems...

The problem is sometimes when I am idling at a stoplight or parked, the tach will go all the way down to 0. The car is still running but the tach will show 0 rpms. Once I step on the gas it will usually go back up. It only happens maybe 60 percent of the time.

Is the Tach electric or mechanical? What would cause it to go to 0 during idle? My Chilton repair manual seems to have every model of Toyota truck, landcruser, etc but nothing that can help me.

Thanks!

dirtyXplorer

Bumpity bump...Does anyone have a link to a FSM wiring diagram? I wnat to fix this soon. I am thinking its an electrical problem.?.?.

Belize Off Road Team

have you tried asking Toyota dealer for a FSM? i've got one, but no way to get it online to show you anything. you can buythem from TOYOTA or eBay.but i would say it sounds more like there is a loose connection somewhere and when you idle it shakes it loose or a wire is grounding out somewhere!

dirtyXplorer

Thanks. I should just go out and buy a FSM. I know the dealer has them but I have seen them online for free, i am a poor college stooooodent

Belize Off Road Team

been there, done that! im pretty sure you canNOT get the FSM for the 2nd gen 4Runners/Surfs online for free, i know you can for other gens. if you try a bit torrent, im sure you might find a free one there.

mt_goat

It's probably the same as the 93 Truck FSM, from the seats forward anyway:
http://personal.utulsa.edu/~nathan-b...fsm/index.html

dirtyXplorer

It is happening more and more. Does anybody know I can look for? From looking at the FSM I was going to check the igniter and coil for any loose/bad connections. Sometimes the non working tach happens with low or rough idle.

mt_goat

Looking at my 93 truck FSM wiring diagram, the tach gets its signal from the igniter via a solid black wire. The AC amp also shares this wire and it also splits off a lead to data link connector 1 (whatever that is, maybe the diagnostic plug?).

So, I'd focus on the igniter and or the wire going between the two. I believe (not positive) that the igniter grounds itself to the body sheet metal so you might try cleaning up the igniter to body sheet metal connection so the igniter has a clean good ground (sand down to clean bare metal). Also check that the body sheet metal to battery ground wire is in good shape (just the short one foot wire going from the battey (-) to the inner fender). Maybe you'll get lucky and its just a bad ground connection. If not it could be a bad igniter or bad wire from the igniter to tach. Let us know, good luck

dirtyXplorer

Thats what I am hoping. The tach wire off of the igniter is the black one. I pulled all the plugs off of it and the coil and made sure all the connection were clean. Everything looked good. I will check the grounds and the surface where the igniter is when its stops snowing.

I was taking to a friend and he said to check the computer. "Sometimes older (OBDI) cars will throw a code and it wont set off the CEL." Is this true?

Edit: I also think I am due for ignition wires, if the PO was right they should have about 70k on them, this might contribute to the sparse rough idle...

Gevo

Sorry to revive such an old thread.. but I'm having the exact same problem and if you found a solution please post it up! Thanks.

d21cruisa

Mine just started this issue, happened the first time the other day. Anyone???

Gevo

So I checked the tach wire at igniter against ground, getting about 70ohms. But that doesnt mean anything until i inplug the other end from the combination meter.... too much work for today.... ill update when i have meaningful info.. lol.