my tach is dead

[91rex]

hey does anyone know where it connects to on the passenger side of the engine bay. and how do you troubleshoot it?? i have no idea everything else in cluster works but it stopped yesterday? thanks Will

 

[jonheld]

What motor is this? I assume 91 from your username.

Tach signal originates at the igniter.

 

[91rex]

it is a 91 3fe , i'm new to the truck thing so where is the igniter and what connection am i looking for? is it a plug or how is it connected?

 

[4x4CPOSEADOG]

it is a 91 3fe , i'm new to the truck thing so where is the igniter and what connection am i looking for? is it a plug or how is it connected?

Look for something like this in your engine compartment on passenger side firewall: 88-93 TOYOTA 4RUNNER LAND CRUISER IGNITER 89621-30010 : eBay Motors (item 150409579025 end time Feb-27-10 22:05:21 PST)

 

[tbjammin]

It should be mounted right underneath the ignition coil on the passenger side (US). I recently replaced my igniter with an aftermarket, and tachometer stopped working.

 

[91rex]

i found it but what would cause the tach to stop working? does it need to be replaced?

 

[fj80mike]

on that note i also have replaced the ignigter with a high performance on and my Tach stop also

 

[BluCrzr]

on that note i also have replaced the ignigter with a high performance on and my Tach stop also

Looks like Ill add my name to the list here. Replaced dead OEM Igniter, and my tach died.

Put the old one back in to test and still dead

I hope the aftermarket igniter didn't fry something

 

[rsocalguy07]

Looks like Ill add my name to the list here. Replaced dead OEM Igniter, and my tach died.

Put the old one back in to test and still dead

I hope the aftermarket igniter didn't fry something

Anything to report here? The same happened to me as well. New igniter and tach is dead now.

 

[jonheld]

Anything to report here? The same happened to me as well. New igniter and tach is dead now.

On the 3FE the tach signal comes from the igniter. The OEM part has been NLA for the last 10 years, so anything that's replacing it is aftermarket.
Unless you know the pinouts of the replacement unit and can make a comparison between the 2, I've got nothing for you.

The OEM unit supplies the tach signal on pin 4; solid black wire that runs to the dash console. It also runs to the diagnostic connector on the firewall pin 18 (IG-) and can be monitored with an oscilloscope as it's just pulses.
If the aftermarket unit is putting out something that the tachometer doesn't like, then it's possible that it's causing these problems. I would contact the manufacturer.

 

[TownsvilleBloke]

Anything to report here? The same happened to me as well. New igniter and tach is dead now.

Hi @rsocalguy07 ,
I just did the same thing and now my tach is dead too apparently.
How did you fix it ?

 

[Intjdan]

hey does anyone know where it connects to on the passenger side of the engine bay. and how do you troubleshoot it?? i have no idea everything else in cluster works but it stopped yesterday? thanks Will

I can't speak on behalf of Land Cruiser but I worked on tons of cars in the past and usually, the speedometer is attached to the transmission. The speedometer cable is a wire round type of cable and they can typically break. If you got a friend, and a drill with a chuck, attached to the cable to the Chuck and then spend the cable with the drill. See if there is a speed being registered on the speedometer. If not then there's a good chance the cable has broke. Try to pull on the cable if it comes out that means it's broke

 

[NeverFinis]

I can't speak on behalf of Land Cruiser but I worked on tons of cars in the past and usually, the speedometer is attached to the transmission. The speedometer cable is a wire round type of cable and they can typically break. If you got a friend, and a drill with a chuck, attached to the cable to the Chuck and then spend the cable with the drill. See if there is a speed being registered on the speedometer. If not then there's a good chance the cable has broke. Try to pull on the cable if it comes out that means it's broke

Welcome to ih8mud.

You replied to a 15 year old comment about a tach issue, which is not a speedometer issue.

As for the original issue, it might be the aftermarket igniters are outputting a 5V pulse, rather than 12V pulse. It could be just a noisy or nonexistent pulse as well.

The only way to know if a signal is there, and the voltage range, is to scope it. You can modify a Toyota tach to accept a 5V pulse, or pull up a 5V pulse to 12V.