FPR setting
 

do you set the fuel pressure regulator with engine on or off? what about the vaccum line that connects to the FPR is it connected or not or plugged-up? what about the vaccum tee on the FPR, plug it or not? i know you set it to 38-40 for best results. this is a used regulator so thats why i am asking questions. thanks in advance....

with the engine at idle pull the vacuum line and check it, and then set if with the line disconnected.

take care,
adam

I've got 30# injectors, 190 intank fuel pump, Edelbrock aluminum heads, TFS track heat intake, 70mm TB and 75mm MAS, I've got an aeromotive frp which I'm about to install. What should my fuel pressure be set at? :confused: A friend of mine said it should be @ 60psi.........but that seems high to me.

no way!! not that high. start out at like 42 or so (i would). and try it.

take care,
adam

The best way to set your fuel pressure is with the engine off. You can turn the fuel pump on by jumpering the fuel pump test lead to ground when the ignition is in the on position. Here's a diagram that I hijacked.

http://www.shotimes.com/pics/eec.gif

Once the pump is running you can easily set your pressure. Set it to 39 psi. You don't have to worry about the vacuum line since the engine is off.

Setting it with the car off and pump on makes no sense to me. Set it with the car running and warmed up, pull the vacuum line and turn the reg with the allen key to the psi you want. Setting it w/o the vacuum is setting it for wot cause there is no vacuum at wot. It will drop when you put the vacuum line back on and thats normal.

mysweetlx, try 35psi with your combo and tune from there. You'll probably need less psi, but the dyno or track will tell you.

Why wouldn't it make sense? You'll have vacuum in the cylinders and the injectors opening constantly (meaning that the system is not closed) with the engine running, not to mention working around a hot engine can be painful sometimes.

Also, with the engine running and the vacuum line off, the engine isn't going to be idling properly anyway since fuel pressure will be too high causing it to run richer than it should.

There is absolutely no reason why the engine would need to be warmed up to set your fuel pressure. The FPR is basically a pressure relief valve that you set to open at a specific PSI.

You'll get better measurements, its easier since you don't have to disconnect anything, and it will be safer.

The engine will be running fine when the vacuum line is pulled off to set fp. I have set it many times. Engine at idle with vacuum off is the way to set it.

I guess you do it your way and we (99.9% of the fuel injected Mustang population) do it our way ;) Take care.

Thanks guys. I'll give it a try - starting at 35psi and work up or down from there. I'll see what happens. Could not having a fpr installed yet be hurting my performance? Do you mean that the car will run even stronger than it is now? If so, that's awesome. :D

whatever you do, dont set it to 39 psi. I always find these engines run better with less pressure, even when modified, try like 36-37 psi, or even lower

There's a lot of things that 99.9% of the fuel injected Mustang population does wrong which is why this board is so busy. :D

Seriously, though, I'm not saying that your way is wrong, I'm just saying that my way is easier and probably a bit more accurate.

Mach 1's recommendation for pressure may be correct, but I think it would depend on the order that you do things. Set the pressure to 39 first and drive it for a few days to let the computer adapt and then lower it to 37. This minute adjustment may be small enough that the computer will not make any fuel delivery adjustments and may give you the results that Mach 1 is talking about.