Sn95 Rail Mount Fp Gauge Face Palm

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
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a van down by the river
Swapped out my kinked fox fuel rails for a set of sn95 rails onto my 89. While attempting to transfer over my existing schrader mounted gauge, I noticed it wasnt reading zero when disconnected. Hmmmm, betcha that could've helped blow the head gasket!

Anyhow, the gauge is the standard Performance Fuel Systems gauge where you can basically twist the housing to calibrate it to zero. There's a spot down below where you can see that the zero is basically a range, not an exact spot. Doesn't this mean the gauge can be off by a few psi as the needle starts to move?? Is there a better way to calibrate these?

kp-1441_6818.jpg



Of course nothings that easy, and now I need to locate a very short adapter in order to mount this gauge at the schrader valve on the sn95 rails, which is actual rail mount as opposed to the fox lines where the port is on the supply lines. Can't keep it there, as a had to do a little creative twisting of the supply likes to mate up to the sn95 rails. Looks like part number 3280 from Autometer will work.
ATM-3280_ml.jpg

Why dafuk don't they make the gauges to actually thread right in?

Rant over....
 
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I've had that same gauge for years and never had a problem. I believe it's just an Ashcroft 15DDG gauge. I can't turn my housing and the needle has always been dead center in the zero area. Ashcroft claims that their 'True Zero' is better than having a pin type needle stop, but I've never compared it to another gauge.
 
I talked to the tech department at PFS, they claim if its not at zero, its defective. They are sending me a replacement at no charge. Awesome customer service right there, but loks like it will be a few days before she gets her maiden voyage
 
I do a lot of work with pressure gauges (I work with natural gas) and I've never seen one with a 'range' for 0. That is odd even for a 100 psi max gauge. All gauges I work with have a bottomed out 0 and the first 10-20 psi (or so depending on the max range) is short but nothing like that. I really like the digital gauges for the precision but that sounds like it would be overkill for a rail mount gauge, hah.
 
Those things should be illegal. I've seen this same story too many times. Mad, if you do need a gauge, then at least get a SS line and run the gauge from the cowl, or get one with the isolator that uses antifreeze for the in dash mounted gauge. Do NOT run a fuel pressure gauge line directly into the interior. ( I know you know this, but posting for the benefit of others)