Okay,
I’m a little bit electrically challenged so humor me here.
I’ve finished an install of a Whipple on an HTM and have run into a slight problem. HTMs come with blower gauges (boost, fuel pressure, etc..) even if there not used at the time of rigging.
So, I wired what appears to be a 0-90 lb fuel pressure gauge to a sender we purchased from Livorsi. I also have a mechanical gauge on the fuel rail. At idle, the fuel rail reads 40 lbs on the mechanical gauge and the electrical gauge reads 50. It gets better; when I turn the key on the dash gauge pegs and then as the electric pump pumps up, the gauge slowly falls from 90 or so back to the 50 lb mark and the mechanical slowly goes from 0 to 40 lbs. Now when running and going into boost it very steadily drops 2-3 pounds when it’s suppose to rise 2-3 lbs.
Bottom line is that the gauge is doing the exact opposite of what it’s supposed to. Instead of pumping up to 40 lbs, it pumps down from 90 to 50 (40 lbs) and responds opposite of how it should.
Did I miss something here?? The two leads on the sender don’t have any orientation (I tried anyway)
Any Ideas???
Thanks,
Dave

I had the same thing happeneing with my gaffrig/livorsi oil pressure gauge. It had a VDO sensor on the engine and with the combo, it was running in reverse. The needle was pegged at idle then would slowly drop as rpm increased. I'm guessing that the sensor and gauge are not matched.
I would call Livorsi.

Sir,

Please feel free to contact Ed at Livorsi Marine, as I have found this post and forwarded it to him - he is looking forward to your call and helping to get you back up and running.

The number is: (847) 548-5900 and he is at extension 217.