i just installed a set of 450cc dsm fuel injectors with a resistor pack on my civic, im running 5psi non-intercooled, tonight after putting the new injectors in the car obviously idled really rough, and bogs down slightly up until the boost starts to balance things out....

what should be my next approach to help out this rough idling or bogged driving?
ive heard of fmu's n stuff, but how do they work exactly, and will it help me?

please let me know any useful advice or helpful links.
thanks!

 

you need the FMU, its a fuel management system. check the one that vortech makes for your car there some on ebay right now. what it does it allows the air fuel ratio mixture to run richer when engaging in higher boost. i think its 1 psi of boost per 12 psi of fuel, i might be wrong on the math, but you definalty need to be looking for one.


[Modified by ELUD THS, 9:54 PM 5/16/2002]

 

You need a VAFC or Hondata to run 450's. I'm suprised it even idles the way you have it now, you'll probably end up throwing a fuel system rich/lean MIL/CEL soon. Read up on the "AFC hack" and "calibrating a modified fuel system". I think thats the direction you need to go.

310's is about as big as you can go without some type of electronic intervention. You'd need an FMU with 310's or lower but not with 450's. 450's will supply enough fuel at stock fuel pressures, no need to raise the fuel pressure to get more fuel in, which is what an FMU or RRR does.


[Modified by 5 Liter Eater, 11:58 PM 5/16/2002]

 

oh ps - i had to drop the fuel psi to 18psi - it pegs 30 full throttle, hehe - just to get a '500rpm' idle....

i got the injectors for FREE, and the resistor pack for FREE too, so upgrading from my stock sohc vtec ones (whatever they are) was inevitable - especially since im running turbo...

i tried doing a search on the two topics u mentioned, but didnt pull anything up
is there any web site or article u can think of that i should check out?

thanks


[Modified by SolidSpruce, 6:11 AM 5/17/2002]

 

i thought that with the 450 injectors, an FMU wasn't needed anymore. i was under the impression that an FMU is needed with stock injectors because the FMU will increase the amount of pressure needed for the car to run right. with stock injectors, along with the FMU, an in-line fuel pump is needed. with the 450's, of course you need the resistor pack, but since they have a greater flow than the stock injectors, the 450's don't need an FMU, but i heard you do need an in-tank fuel pump. i just got into the whole turbo thing a short time ago so i've spent most of my time asking questions and do some research, but to be honest, i'm still a little confused on some things. as far as what i just said though, i've read things like this over an over again, but if i'm wrong, by all means, correct me.

 

Again, I'm suprised it's running. 18 PSI is below where the injectors can atomize the fuel well. at 18 PSI it's kinda of just dripping out, well not really, but its not good.

You'll never be able to get the 450's to work right throughout the RPM/vac/boost range just by altering the fuel pressure.

The search function here is really picky. The only way I found info on the AFC hack was by searching the FI forum for "AFC hack" using archived posts.

 

You guys are missing the whole point here. The program in the ECU can not controll the 450cc injectors. Max would be 310cc. Now you either need the Apex VAFC hack or some sort of stand alone like hondata. You cant just put those injectors in your car with the stock OEM Ecu program and expect it to work.

art

 

http://www.autospeed.com/A_0008/page1.html
http://www.theoldone.com/articles/regulator/

The first article is on how to modify the MAP signal in order to run larger injectors. (Autospeed is the ****)
Second article is on lowering idle fuel pressure.

I'm going to be doing both of those in the next week or so and see how things run...I may end up getting a VAFC (probably will anyway in the future) but, I think this should run pretty well. I'll be sure to post the results, unless they suck

 

http://www.thedropshop.tv/vafc.htm

setting up your vafc to work with 450cc injectors

 

http://www.thedropshop.tv/vafc.htm

Oh yea, I forgot about that site already!

 

http://www.thedropshop.tv/vafc.htm

You're welcome!