Thread: Just got a car, fuel pressure regulator unhooked, very confused

My '93 Sentra SE-R (SR20DE) I just got had an issue where it would die when I come to a stop in the car. Be driving down the highway fine, go down an offramp, push in the clutch and put the car in neutral, revs would drop, pause at 1000rpm or so, the car would chug a couple times and then die leaving me at the bottom of the ramp with my sh*t battery trying to start the car again. Looking around under the hood revealed a bunch of upgraded engine-to-body grounds with what looks like 8 gauge wire, and the MAF has been grounded to the intake manifold. Cool. I also noticed a purple aftermarket (I'm assuming) fuel pressure regulator that had its vacuum nipple capped off. Likewise, the nipple on the manifold that was the same size was capped off. I grabbed some vacuum hose from my Big Pile O' Spares and hooked it up and the car hasn't died since, but it's significantly down on power and smells a bit rich (though that smell could be from my horribly leaking exhaust manifold or my leaky fuel vent line).

Any thoughts on why my car would have an aftermarket FPR on it and why it wouldn't be hooked up to vacuum? I didn't see any adjustment screws on it and there's no pressure gauge on the fuel system right now for me to check my pressures.

It's possible that is was leaking past the diaphragm and sucking liquid gas into the intake manifold. That would explain loss of power and smelling like gas.

That's a good thought. If I left the vacuum nipple on the regulator and ran the engine, revved it, etc. and stuck a white paper towel next to the nipple I would see gas on the towel if it leaked, right?

Possible. Does the vacuum hose coming from the regulator after running engine smell like gas?

It doesn't seem to. I might have to go on a longer drive though. I unhooked it again and instantly the butt-dyno results were astonishing. I thought these vacuum operated FPUs didn't do anything at WOT? Very confused on how these operate. Found an image of that my regulator looks like on the Interwebz, if anyone can tell me why this would be installed on a mostly stock NA SR20DE

You need an oem regulator for a stock DE. Without a fuel pressure gauge, you don't know what the pressure is set at with that turd. Proper fuel pressure is critical to good operation, power, and fuel economy.

That's what I figured. I just sold my Mustang so I have the cash to throw around for a stock regulator. Looks like I'll be out about $40 on eBay, which isn't too bad for the peace of mind. Hopefully it'll get here before the next autocross.

I dont have one,but if you post a wanted thread here I bet someone has a used on for like half that ebay price