What does this sensor do

[toxicroadkill]

I just bought a 1986 hmmwv, completely stock. Im slowly learning about the vehicle, but one item has me wondering, on the back of the engine right by the bellhousing where the vac pump would be on a cucv, there is a sensor of some kind. Can someone tell me what it does?

 

[HoveringHMMWV]

Not sure which sensor you're speaking of.

 

[NDT]

He is talking about callout 4. That is the tachometer sensor that provides engine speed data to the STE-ICE diagnostics tool. Leave it in place to keep water out of the oil pump drive.

 

[Retiredwarhorses]

He is talking about callout 4. That is the tachometer sensor that provides engine speed data to the STE-ICE diagnostics tool. Leave it in place to keep water out of the oil pump drive.

well, it’s actually needed there to engage the oil pump via the cam shaft…

 

[papakb]

That sensor is an RPM detector that's used by the STE/ICE test set to measure engine RPM. It doesn't report to anything else and is not critical to the operation of the vehicle.

It can be used to send a signal to the tachometer if you have one installed.

 

[Milcommoguy]

That sensor is an RPM detector that's used by the STE/ICE test set to measure engine RPM. It doesn't report to anything else and is not critical to the operation of the vehicle.

It can be used to send a signal to the tachometer if you have one installed.

Not critical ?? Spins the oil pump and keeps the oil in. Don't take it out.

Me just a critic of red typing, CAMO

 

[Mogman]

I think we are talking about the RPM sensor and it is not needed unless it has a tach. NOT the oil pump drive, they are two separate things, yes you want to leave the sensor in place to keep water from infiltrating the oil pump drive.

But actually he was just curious what it was, he never said anything about removing it...

 

[Mogman]

Also it sits on top of the oil pump drive which would be powering the vacuum pump on the CUCV, YOUR HMMWV has no vacuum source so it has a mechanical "kickdown" cable to the 3 speed TH400 instead of a vacuum controlled servo like on the CUCV

 

[toxicroadkill]

thanks all, i couldnt figure out why it would need a sensor for the engine speed..the diag deal makes sense

thanks again everyone

 

[Milcommoguy]

Not critical ?? Spins the oil pump and keeps the oil in. Don't take it out.

Me just a critic of red typing, CAMO
View attachment 875373

You guys are right.... For some reason I was thinking he wanted to pull the whole assemble out of the engine.

Now I am seeing red, CAMO