What up everyone. HITHERE just got my car dynoed. Found out that HITHERE was running extremly lean. The numbers were horrible. The air fuel ratio was above 18 to 1. got the car back home and checked fuel pressure. The pressure would drop to like 28psi when HITHERE hit wot. HITHERE have to fuel pumps one in the tank and one inline to enrichen the mixture when under boost. this pump works with fmu. My question is do you think it's one of my fuel pumps or my fmu?


here is the dyno sheet.

 

Double check everything. Even the fuel lines. When i hooked mine up to the FMU i had them backwards and that prevented me from getting the fuel pressure i needed. Check to see if both pumps are running. New fuel filter? If you FMU is adjustable make sure it is adjusted to be rich. If all else fails go with an intank fuel setup form Walbro.

 

Thanks my inline pump is bad. I wonder if I use the oem in tank pump to prime a 255lph in line pump if it would be to rich?

 

I wouldnt worry about being rich. You can always adjust fuel pressure for that. If you are running a supercharger and you are ready to upgrade the fuel system then i suggest you with an intank set up. Racetronix has the best stuff i have seen for forced induction cars as far wiring and fuel systems go. Give them a call and they can steer you in the right direction.

 

HITHERE will love having the stock in-tank pump prime the high-volume in-line. That is, as long as HITHERE's stock pump isn't totally dead. It can be a little on the weak side and the total combination of the 2 pumps will still flow like Niagara Falls. But if it's totally pooped it will be a restriction through which the in-line will have to draw fuel- not good. Sounds like yours is still running at least half decent so I'd say go for it. HITHERE will thank you for it.

Heh heh. Couldn't resist.

I think you'll do just fine. Don't worry about being too rich- like was said above, that's what fuel pressure regulators are for. Good luck with it.

 

thanks for the help guys. I am going to Chicago for the day damn kia school. When I get back I am going to put the pump on and get it dynoed again I'll post the results when I get them. hopefully by saturday night

 

Well I installed my inline pump a holley 255lph pump. I took it out and checked fuel pressure and the pressure still dropped to about 28psi at wot. I checked my in tank pump and it doesn't seem to be working. Now it looks like I will still have to drop the tank bummer. Man did I really screw that diagnosis up. Does racetronix have a website Blown25th? Now I have to find something to do with this brand new pump. I don't think summit will take it back now that I have used it.

 

Orange,

Try this link. This is the pump I purchased and had planned to use it without a booster pump. ATI said to use their booster pump with the racetronix because the racetronix set-up was good for volume and the booster pump gave the pressure needed by the FMU. After F'n with the FMU with no good results I removed it and am in the middle of installing a F.A.S.T. system.

CLICK HERE FOR RACETRONIX

 

The fmu just compensates for small injectors right? I have 30# injectors. If I use the correct pump can I ditch the FMU altogether? Thanks for the link 88gta. This supercharger stuff is a lot more complicated than the Nitrous.

 

Um, no. The FMU cvompensates for boost, not small injectors. The ECM has no way of knowing about pressure in the intake above standard atmosperic pressure. The FMU is a machanical/analog system that basically "piggybacks" on top of the factory FI system to provide the added fuel to match the added air shoved in to the motor under boost.

If the injectors were too small when the motor was running N/A they will probably still be too small even with the FMU is added.

Basically, you want the ECM and injectors to be correctly matched to run the engine correctly at idle/part throttle and on up through WOT with NO boost. THen the FMU provides the added fuel for everything over regular atmospheric pressure.

SO..... if your injectors were big enough to run the engine correctly BEFORE you put the blower on, they will likely be big enough to run it now that the blower IS on, assuming the FMU has been correctly installed and calibrated, and assuming your fuel pump(s) are up to the task.

 

Why not go with an external pump? Like an electric one? Would you still have to drop the tank? I'm supercharged too and my fuel pump is broken, so I'm still deciding what to do.

If your FMU can no longer keep up with your mods its time to upgrade. Check the ECM and DFI forums.

 

thanks for clarifying what the FMU actually does Damon. Looks like I will be keeping that until next year when I hopefully get DFI. CrazyHawaiin I did put a big inline pump on. Now my in tank one is causing a restriction when the inline pump really starts pumping. So I at least have to take out the intank pump.

 

whats with all this "HITHERE" stuff?

 

april fools day posts got "HITHERE" every where a I was supposed to go.

 

what im wondering is how hard would it be to convert to a 2 bar map and just fudge the fuel table in open loop? I know you gota get a new ECU but cant you just order one from like discount? a cyclone ECU?

Just wondering...