Vacuum Adjustable TBI Fuel Pressure Regulator

[dave w]

I meant the vacuum line of regulator?

The Coast Guard requires a drain for the fuel pressure regulator in the event the fuel pressure regulator should leak. When fuel leaks from the fuel pressure regulator, the fuel will drain onto the throttle bade. The marine version does not use a vacuum hose. The marine fuel pressure regulator can be used as a vacuum referenced pressure regulator when using the CORRECT pressure regulator diaphragm.

dave w

[EagleMark]

AH.. now I get it! The regulator was sealed for Coast Guard approval... but because of that works as Vacuum adjustable...

[dave w]

AH.. now I get it! The regulator was sealed for Coast Guard approval... but because of that works as Vacuum adjustable...

Will NOT work as vacuum adjustable with STOCK pressure regulator diaphragm. The vacuum adjustable diaphragm is different from the STOCK pressure regulator diaphragm.

dave w

[EagleMark]

What's the difference?

[dave w]

What's the difference?

See attached pics. There is a seal in the piston.

dave w

[gregs78cam]

Dave, I got the lathe almost done, need to finish a couple of small details, but I made a couple of test cuts that turned out really sweet. As soon as I get it back together and figure out the best way to cut the inside step, I will get one made. I haven't heard anything from my CNC guy yet.

[dave w]

Dave, I got the lathe almost done, need to finish a couple of small details, but I made a couple of test cuts that turned out really sweet. As soon as I get it back together and figure out the best way to cut the inside step, I will get one made. I haven't heard anything from my CNC guy yet.

That's awesome. Thanks for the update.

dave w

[gregs78cam]

OK, so here it is, most everything is within 0.003". The only part that was really hard was the internal step which I think is for placement of the spring? So it's not real critical, right? If I had the right tool it would be a lot easier. I will take a stab at grinding a suitable tool. It's definitely not CNC, but I am still learning all of the little quirks on this machine.

[EagleMark]

Sexy!

I don't even need one but I want one! Make some more that can be set up for adjustable, then drill hole and thead for a nipple in the side for vacuum.

[dave w]

OK, so here it is, most everything is within 0.003". The only part that was really hard was the internal step which I think is for placement of the spring? So it's not real critical, right? If I had the right tool it would be a lot easier. I will take a stab at grinding a suitable tool. It's definitely not CNC, but I am still learning all of the little quirks on this machine.

Looks AWESOME!

The internal step is for the spring, and shims to increase spring pressure / fuel pressure. I've been using parts (springs / pressure regulator diaphragms / gaskets) from TBI Parts http://stores.ebay.com/TBIPARTS/_i.h...4.l1581&_pgn=1 for my testing.

dave w

[EagleMark]

We found thos springs once here in a thread? Like 6 for that price at:
http://www1.mscdirect.com/cgi/nnsrhm

[gregs78cam]

I could go out to the shop, dig through my junk, and take an injector pod apart and check this, but I guess I am lazy, the spring fits around the step on the inside, right? And you add shims under it? The step on this one is about 0.100" lower than the drawing, will that make any difference? The bottom is still right just not the stub that sticks up off the floor.

[dave w]

The spring fits around the step on the inside, right?

Yes.

And you add shims under the spring?

Yes.

The step on this one is about 0.100" lower than the drawing, will that make any difference?

No.

The bottom is still right just not the stub that sticks up off the floor.

The stub is a carry over design from the factory regulator design. The stub could be threaded for an adjusting screw, but the vacuum nipple does not have enough thickness for threads.

I decided not to use a threaded side wall vacuum nipple, because it would need a much thicker wall thickness.

dave w

[gregs78cam]

Cool.