fuel pressure regulator

[jdhogg]

you guys have told me a few times that this is a critical thing.what wood i buy to replace the stock one and where do i get it.what pressure do i need to run,sorry for all the dumb questions but im trying to get stuff done this winter

[KRUZER1]

your runnin a NA 4.3 in an mg right? if so you only need a stock fuel pump and youll be fine. are you tryin forced induction?

[rat]

your runnin a NA 4.3 in an mg right? if so you only need a stock fuel pump and youll be fine. are you tryin forced induction?
I think he was talking about the regulator, the fuel pump doesn't have any thing to do with fuel pressure, except when it doesn't pump enough fuel, then it will be lower than set at wot generaly. The regulator is what sets the fuel pressure. It generaly on a return style system(i think the stock tbi is right?) it pinches the return line, and restricts the flow of un used fuel back to the tank. Installing an adjustable one can be used as a tool for tuning.



As far as installing an adjustable regulator i am sure someone with more experience can chime in with exactly how to do it. Tbi's should run around 9-13psi of fuel pressure i think. If you find that you are running lean, then you could raise the fuel pressure, and the same for the other way around. A scanner would be handy to check your fuel trims to see if it is running lean or rich. The only real way to do wot though is with a wideband, or some sort of exhaust anylizing equiptment. Or, dyno/1/4 mile time could be used to fine tune the wot a/f mix.

[T Man]

Actually on a tbi there is a diaphragm with a spring that holds pressure on it. Diff. spring=diff presure. There are good adjustable ones avaliable out there. IF you look at your TBI unit, it is the small gold looking bowl on the Injector pod assembly

[rat]

It should probably also be mentioned that you should figure out how your engine is running before doing this. You may find that the stock fuel pressure is fine. It will also help when determining what way to go should you decide you need to raise or lower fuel pressure.

[T Man]

TBI Should be at 13 psi. Bump it up and you risk running rich on a stock engine. TBI's HATE richness, kills the o2 and makes it a turd

[Maximus]

If you are gonna get a an adjustable regulator also get a gauge.Every TBI engine is different and depending on what is done to them will need different fuel pressure.If you get the gauge you can see what yours is running at stock and go from there.Most TBI 4.3's will like a little more pressure even on a stock engine.But don't go over kill.I raised mine in small increments till it started running a little rich then backed it back off to were it was running at its best.As you do more to the engine that requires more fuel you will have the flexibility to adjust for the changes.And a gauge is a must have once you start making those adjustments.

[jdhogg]

well i been checking on how its been running and shes a little rich now,i was thinking of retarding it a bit.its almost she floods just a bit when i first get on it until the rpms come up

[RinksRides]

I ponder if the stock reg can be boost referenced? hmmm Lemme see here....

To Be Continued!