TOPIC:

what the hell ports are for what???? i know which ones vaccum...which piece of fuel line goes to which port??? and which way reduces pressure/increases pressure??? Damn thing came with no instructions:huh:




Post edited by: tnutz, at: 2007/03/06 18:33

I would venture a guess that the barbed end thing receives vacuum, which opens it up. Fuel probably can flow either way once that happens.

well i knew which one was vacuum.

tnutz wrote:

well i knew which one was vacuum.

Hi tnutz
Would you think that if fuel flow were directional, it would have an arrow or sumpin'? I would, as everything I know of that is _not_ bi-directional is marked somehow.
I don't know, obviously, but you should could orient it for most convenient connection configuration.
I would test it by connecting your vacuum source, then blow or suck in both directions. If you can pass gas in both directions, then you can pass gas in both directions.

It's not bidirectional, the port on the side is the fuel return port, the one on the end is the input port. Normal practice on EFI systems is to mount the fuel pressure regulator after the injectors, it regulates the pressure by returning excess fuel to the tank.

Reverse the connections and it won't work.

Oh yeah, screw in the barbed fitting to increase pressure, unscrew it to decrease pressure.

Post edited by: steell, at: 2007/03/06 21:13

thanks, i knew someone would know forsure, figures it has to be backwards of stock...or so thge pics in my book say.

Post edited by: tnutz, at: 2007/03/06 22:54

Why are you installing an adjustable fuel pressure regulator? No other injectors available to fit the ports in the head and engine mods require more fuel? A programmable controller would be better.

to see if can get a bit more fuel in the mix. not alot. but enough to compensate for straight pipe.

If I recall correctly, that bike has a mass air flow sensor that should compensate for the straight pipes, have you put an AFR meter on it to determine that the EFI is not providing enough fuel?

Spark plug reading will get you in the ballpark, but you just can't beat a wideband sensor with controller and a gauge.

Take a look HERE

i thought 81's didn't have that. only an idle sensor, airflow meter and WOT switch.

No. he's asking if you've had the exhaust tested for your air-fuel mixture. The mass air flow sensor is that ugly chunk of aluminum with all the wires attached to it that's between your air plenum (black plastic "box" just behind the throttle bodies) and the air cleaner box under the seat. That should be able to compesate for a different pipe, but mine, with an aftermarket 4-1 always pinged under full throttle, and if I did a full-throttle chop, the plugs showed lean. If he's going to stick with the stock system an AFPR is really his only choice.