Drilling and tapping Injection Pump for RPM sensor (1 Viewer)

[mcaz5]

Any thoughts on whether or not this would work for a 2lt pump? Apparently my pump doesn't have the hole tapped from the factory. None of the 2lt engines in the US came with a tach so I guess that's why there's not a hole pre tapped, but I know basically every other country had the NA 2ls with tachs. I purchased a cluster out of an LN61 and want to get the tach working in my LN65.

This isn't my pump pictured below, but the you can see where the rpm sensor goes, it isn't tapped. Obviously the biggest concern with drilling is making sure all the metal filings are removed

 

[4Ruster]

I would not recommend it. The tiniest bit of metal lost in the pump will cause a lot of damage

 

[Gimme a 60]

There has to be a better way to get a tachometer. Perhaps tapping the bell housing….

 

[veiloctane]

autometer makes a tachometer that reads off of the alternator signal I'm sure there are others just a quick google search away

DIESEL TACH ADAPTER

9112 RPM SIGNAL ADAPTER FOR DIESEL ENGINES

www.autometer.com

 

[sodafeld1]

A few members reckon the 'tiny tach' is a goer, it reads from a sensor clamp on pulses going through a hard fuel line after the pump. Which baffles me, but folks say it is good. I am tempted to get one when I have that sort of spare cash one day..

 

[mcaz5]

There has to be a better way to get a tachometer. Perhaps tapping the bell housing….

autometer makes a tachometer that reads off of the alternator signal I'm sure there are others just a quick google search away

DIESEL TACH ADAPTER

9112 RPM SIGNAL ADAPTER FOR DIESEL ENGINES

www.autometer.com

A few members reckon the 'tiny tach' is a goer, it reads from a sensor clamp on pulses going through a hard fuel line after the pump. Which baffles me, but folks say it is good. I am tempted to get one when I have that sort of spare cash one day..

I’ve seen all these options before, but the plan was just to purchase the factory pickup sensor(rpm sensor) which I have. That’s what installs into the injection pump and connects to the factory tach gauge cluster which I also now have. I want to use the factory tach, so unless any of these could be modified to display on the factory tach, then I’d prefer not to use them

This was supposed to be super easy until I pulled my pump last night and realized that I didn’t have a factory tapped hole in my pump already. So the pump is already out on the bench and I have everything to make this work, other than the tapped hole in the injection pump body.

 

[sodafeld1]

I consider anyone who fiddles with diesel pumps without the very clean specialist equipment to have extremely large testes.

Personally, I bend original concepts I have had, to make life easier as it is short and expensive either way.

If there was no other way but tap into your pump, I imagine the safest way would be to pull it apart to insure the internals do not capture the tiniest bit of metal shaving. Which probably means a diesel specialist and lots of money. But certainly approach a specialist and get a quote. Nozzles are extremely fine tolerances.

Or source a known good pump with the required hole for your factory tach. Which would be lots of money too.

Sorry to be a smarty pants. From over here one of the aftermarket options seems way cheaper and easier. The 2h tachs from the bell housing, which would be more agreeable to fiddle with..

 

[veiloctane]

There are people u use aftermarket rpm pickups to use with there factory cluster. And they can adjust accuracy using a resistor. I believe the diesel tachometer is around ~5vac

 

[Dougal]

Is there any other way to fix the pickup without cutting metal?

What tooth count does the pickup need? Is there another location that can get you the same signal with less invasive surgery?

 

[DivByZero]

How deep are your pockets, and are you on the clock? In this situation, there are a few other options. You could source a 2LT injection pump with the hole already present in the housing. I see a few on ebay for reasonable prices. I believe Denso also still make the housing, so another possibility would be to order the new housing with the hole drilled, and send your pump and the new housing to a reputable shop and have them rebuild your pump into the new housing.

If you want to go ahead with the drilling route, my concern is that I don't think you can do this safely without basically fully disassembling the pump, and then you've got a pump rebuild and calibration to do anyway, and the parts are moisture sensitive and very difficult to handle at home. You'd also need to be able to precisely drill that hole, I don't expect there'll be much room for error.