3.1 4JG2 Tachometer

[JBjunior]

What does the 3.1 4JG2 use to send a signal for rpm to a tachometer? I don't currently have a tach at all so I am starting from scratch, interested in what may already be there?

[isuzurob]

the pick up is in the injector pump on the inside by the block, need to use a diesel rev counter as petrol wont work

[JBjunior]

Thanks Rob!

[JBjunior]

Moving forward on this. I should be getting a factory Isuzu gauge cluster that has a tach later this week. What connects from the pick up on the injector pump to the tach, is it simply an electrical wire? I think I will be able to "calibrate" the tach somewhat based on what others have done. Any information would be greatly appreciated.

[geeves]

it is just a wire and will be identical on the 2.8 and 3.1 diesels so should just work.

[JBjunior]

Thanks geeves. Also evidently there is a potentiometer for adjusting the tach so I will have to figure out idle RPMs and RPMs at various speeds/gears to dial it in.

[JBjunior]

I will be using a calibrating tachometer, hand held, to dial in the tach. What is the normal idle for the 3.1?

[JBjunior]

Is the tach connection a two wire that goes into a connector?

[JBjunior]

Anyone know?

[geeves]

this is robs areana

[isuzurob]

if it was mine i would just use a tacho out of a 2.8 bighorn, tacho is a 2 wire set up, i havnt seen adjustable diesel tachos?

[JBjunior]

We have adjustable ones out of the 4 cylinder pickup that drop right in to the Amigo. I will use a hand tach to calibrate it. My question pertains to the wire on the backside of the injection pump appears to be a 2 wire into a single harness. I will have to figure out from there how to get that to the actual tach.

[JBjunior]

Rob, there is a black/red and another wire coming off of the tachometer pickup. The black/red corresponds to the black/red coming out of the gauge cluster, where does the other wire go?

[EdwinSantiago]

Where you able to figure out where the two wires coming out of the pump connect to?