Fuel Rail Pressure Sensor Calibration?

[rbattelle]

Banks doesn't have one...

 

[rbattelle]

Bringing this project back up...

I have sourced the op-amp I need, as well as an appropriate 3 mA panel meter. The only thing missing now is a good splice to the rail pressure sensor. I am reluctant to physically cut-and-splice the wiring, for fear of messing up the signal to the ECM. I would rather get a molded plastic splice connector like what Dr. Performance apparently includes with their module (Banks too, I think).



Neither company was willing to sell me one. Does anyone have any ideas? Anyone have a broken/failed/faulty Dr. Performance or Banks module laying around?

 

[sag2]

When I was fooling around with mine I just cut the wires. I figure thats what they make solder and shrink wrap for.

One interesting note, I ran out of time one day and just spliced the wires using a splicing ring (looks like a slice of brass tubing) to hold it together until I had some more time. The truck started blowing black smoke all the time, and mileage went down about 3 mpg. I finally gave up on the project and soldered them back together, and it fixed it. Must have been a little extra resistance in the sensor circuit. Also you will see the wires are wrapped very tightly from the sensor. I cut them a couple inches back from the plug so they are under the convolute tube when it is repaired.

 

[rbattelle]

Originally posted by sag2

The truck started blowing black smoke all the time, and mileage went down about 3 mpg. I finally gave up on the project and soldered them back together, and it fixed it. Must have been a little extra resistance in the sensor circuit.

Sag, with my luck anything I do to those wires (even soldering) will produce the black smoke/mileage loss... I just know it.



I was thinking of maybe directly modifying the connector that's on there now, and leaving the wires alone.

 

[sag2]

You could always cut them way back in the harness where no one would see they were spliced. As long as they are soldered back together properly it should be the same as never cutting them. But use the good shrink wrap that has the sealer that melts out when you heat it.

 

[Matt400]

If your 5v meter presents a 5K input impedance, then you have to start worying about the output impedance of the transducer itself and its effect on what the ECM sees. you dont' want small errors, you want zero errors. The thing about after market engineering is that you must absolutely guarentee zero effect on the stock circuit. For this reason I agree with Jnutter -- you need a very high imput impedance meter. I would choose not to load the transducer with 5K ohms, prefering instead at least a couple of megohms and (better yet) over 10 megohms. That approach removes all doubt, and frees you from having to research the design of the pressure transducer.

I found a meter with 100K ohms impedance, maybe not good enough.