Fuel injection Questions on a 93 3.1

[DeathScythe]

I was thinking about upgrading the fuel injection setup on my 3.1 since I'm rebuilding it. I was wondering what the lbs/hr is on the stock injectors. I searched the forum and read that it was 16.7 but was wondering if someone could confirm this. Also is there an adjustable fuel pressure regulator for the 3.1. I know there is for the 3100 but have yet to find one for the 3.1. If there isn't is there anyway to make the 3100 fuel rail and 3100 adjustable fuel pressure regulator to work on my 3.1. Thanks.

[SappySE107]

Unless you are boosting it or doing a hybrid setup, there isn't much reason to upgrade your injectors. They are 16.6#. The only way to use the 3100 rail is to use the 3100 heads and manifolds.

[DeathScythe]

You know if anyone makes an adjustable fuel pressure regulator for the 3.1.

[SappySE107]

Not specifically, but there used to be one that went after the stock regulator. You could probably do the same thing by taking the return line off the stocker and routing it to another regulator that is adjustable, and then to the tank.

You will need to tune if you do this.

[mickaz]

the real question is Why you do this? it is a useless mod ( if you have done nothing to your engine.)

[LeftVentricle]

Stock 3.1 injectors are 15 pounds. If you really want more flow you could get injectors and fuel pressure regulator from a turbo Grand Prix engine. They should attach to the stock rail and flow 22 pounds. But I'll second mickaz, it's not really necessary on a stock engine.

[SappySE107]

Where do you find that they are 15#?

[DeathScythe]

The reason I was looking to upgrade is because I'm installing a cam. getting a chip from Ben, installing a WAI or K&N drop in with a modified air box; and doing 2.5 mandrel bent exhaust from the down pipe back. I'm not going crazy with the fuel injectors, I was just going to upgrade to 17lbs injectors to get a little bit more fuel and have new injectors than the ones I have that have that have 250k on them.

[SappySE107]

What cam? I am pretty sure you are going to be better off with stock injectors if you want me to tune it. The 260 grind is fine with stock injectors. The manifolds are too much restriction to give you enough HP to require larger injectors. That is just how it is and the main reason the hybrid setup is so highly recommended (3100 top end).

[DeathScythe]

Thats fine the main reason was that I didn't want to rebuild the motor and put 250k injectors back in and have them go out in 30k. I figured that the .4lbs more would make that much of a differance and the stock injectors cost more.

[bszopi]

While you are doing the rebuild (or cam swap, whatever), just send the injectors off to a company like Witchunter to get cleaned and balanced. Then you will have basically new injectors for a fraction of the cost.

[LeftVentricle]

Where do you find that they are 15#?

I don't recall. I think it was the Siemens website? They sell fuel injectors...? I'll have to check some older posts over at A-body, one of the guys there linked to the info.

[Superdave]

nobody really knows what they are.. the bin file says 16.5 lb/hr but that's just a marker.

Stock 3.1 injectors are 15 pounds. If you really want more flow you could get injectors and fuel pressure regulator from a turbo Grand Prix engine. They should attach to the stock rail and flow 22 pounds. But I'll second mickaz, it's not really necessary on a stock engine.

um, not quite. the FPR is the same between the turbo 3.1 and the LHO. the TGP injectors are larger @ 22lb/hr but run at the same 43.5 PSI.