Hey guys. Can one run a mechanical fuel pressure gauge inside the car and still pass tech. at the local track? I heard no, but then I also heard yes using an isolator or something? What the story? Thanks guys!

P.S. I got a good deal on a mech. fuel pressure gague and have it, but don't want to mount it outside of the car!

 

never seen it done, but I have heard of people using an isolator. I think it uses another fluid to keep the pressure.

 

Strongly recommend against using a mechanical gauge inside the passenger compartment. It's not a matter of "passing tech"... its a matter of personal safety.

I had an AutoMeter mechanical fuel pressure gauge with their #5280 "high pressure isolator". The isolator mounts at the firewall, and transmits the fuel pressure on the firewall side, through a rubber diaphragm, to glycol solution in the tubing inside the car. It is extremely difficult to get the internal system full of glycol and keep it full. Then, the "high pressure isolator" ruptured, and I found fuel inside the lines in the passenger compartment. AutoMeter eventually "recalled" the isolator, and they gave me credit for the isloator, gauge and braided hoses toward their electonic fuel pressure gauge.

AutoMeter has now come out with a new model #5282 isolator (#5281 was also discontinued because of problems - do you see a pattern developing here????)), and it costs approx $130. Add the cost of a mechanical gauge, the isolator, the braided S/S lines and fittings, and it will cost you as much or more than the high-end electronic AutoMeter gauge.