What questions should I ask before installing one of these WB-762s on my already-tapped fuel rail test nut? It looks more compact than the variable-resistance senders I've seen, and varies voltage linearly from 0 to 5v to boot.

(Image is live link.)

 

Hi I would leave the fuel pressure gauge attached to the rail in the tapped hole and get a mixture reader that you plug inline to the O2 sensor that is really a better way to read the status of your fueling system, plus you might want to hook up an adjustable fuel pressure regulator, Dave Lomas can hook you up at Motorsport.

 

Good question.

Are you sure that your sender will fit the test nut? If not, what you need is an adaptor that screws into the end of the fuel rail and can hold your pressure sender. And not leak....



I'm about to [finally] install the triple gauges on my A-pillar and need to do the same thing you do. What size are the threads on the end of the fuel rail? I know of a machine shop that can make the part.

N-

 

The problem with the test port is the ball bearing they have inside is an integral part of the seal. It can be a PITA to get the cap to seal with the sender installed.
just a heads up

 

I keep shaking the lenses off the VDO fuel pressure gauges, which is expensive and makes me nervous. Besides, I've already installed an Innovate LC-1, which I monitor with my laptop, and I'd like to add in the fuel pressure input (as well as RPM, accelerometer and EGT) through an LMA-3.

The adjustable FPR is on order with the X-pipe

 

I had my friendly neighborhood mechanical wizard drill and tap the test port nut for 1/8" NPT. We removed the ball and milled an o-ring groove into the open end of the nut (the proper depth, according to the mechanical wizards' book of spells, for optimal compression of the o-ring I selected). The MSI sender I'm looking at also has 1/8" NPT threads, so it should be an easy swap.

 

Normy,

The test port is male M12X1.5 (per PET). So if you took a piece of metric hex stock, tapped one end M12X1.5, tapped the other end 1/8-27 NPT, and cut an indentation in the metric (fuel rail) end for an o-ring, you'd have a handy-dandy fuel rail pressure gauge adaptor. The question is: what material do you use?

 

Update: this sensor appears to be an American Sensor Technologies AST4100.