*** FOR THE LAZY PEOPLE THAT DONT WANT DETAILS HERE IS A SHORT VERSION AFTER ABOUT 3K CAR COMPLETLY LOSES POWER I THOUGHT IT WAS BECAUSE I WAS RUNNING IT ON A STOCK FUEL SYSTEM THEN I GOT 450CC INJECTORS AND A 255 WALBRO FUEL PUMP BUT ITS STILL DOING IT, PROBLEM CAN BE CUZ THE CAR IS NOT YET TUNED THATS WHAT IM THINKING JUST WANTED TO HEAR THOUGHTS***

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for those that wanna read :

just a side note to the people that are gonna flame with "why are you driving a un-tuned car!?" -answer is becuase if anything is to go wrong i want it to go wrong on my first pull cuz if u take it to a tuner and it blow up u still gotta pay him and hes not responsible.




It probably isnt but i have never ran into this problem before in my entire life

heres basically the build

junk yard turbo kit home fabbed and ****


i built a b20vtec and decided to turbo it cuz it was low comp so i finish the motor and slap on the turbo kit and decide just to take it for a few spools to make sure it was all correct tho at this time i ran using stock fuel pump and stock injectors, when i would hit about 3-4k RPM the motor would just go face down lose all power almost as if the fuel pump just completly shut off. so i ended up cracking ring glands on the piston. so i go back to the fort and this time pick up some manley pistons, ported the head and i did a few other things ARP rod studs etc.. and this time i put on some 450cc DSM injectors with a walbro 255 fuel pump
and i just noticed that my 94 integra LS does not have a resistor box for the injectors so i picked one up. I do have FMU it might be a 1:1

anyways too much bullshit im talking too much, has anyone herd of anything like this happening?

to sum it all up im thinking its only doing this cuz its untuned & or i might need to get a fuel pressure regulator even tho i have a FMU.

 

needs tune... besides you have no way of troubleshooting it without some electronics that you can read stuff off of (i.e. tuning software package)

 

the tune is coming 100% sure and im not driving the car anymore until its tuned but i mean with the fuel system i have i figured the car should atleast be able to pull thru the gears maybe not sounding/feeling so great but atleast pull thru..

 

It will not "pull through gears", especially with 450 injectors AND an FMU, before it is tuned. You'll do nothing but flood the engine with fuel, and destroy the new internals that you had installed.

Best bet. Get the injectors out, throw away the FMU, either put the stock injectors back in and drive to the tuner, and install the RIGHT injectors. Or Tow the car to your tuner. No more "pulling through the gears" for you, sir.

 

you stated completly the obvious and no help at all, theres nothing wrong with DSM injectors and a FMU. a FMU is just to pump fuel pressure per pound. all it is is a "boost senstive regulator". so thanks for nothing

 

he did just help you out. The dsm injectors are far too big for the stock fuel tables you are running on your current tune. that's the reason the why the car runs like crap. If you don't get a another chip for the parts you added you will wash the cylinders and you be right back to pulling the engine apart again.

 

thats not a good way to get any help.....especially from a man who knows his stuff......and if what he stated is completely obvious then why is it on your car in the first place??? lose the attitude or lose the help

You want to know why FMUs are the fail. Ill explain it to ya. they add fuel based on boost pressure. It doesnt matter what rpm you are at. Engines will consume more fuel at higher rpms, so if your getting the same amount of fuel at both low and high rpms, your gonna run the motor rich down low and lean up high.

For example: If you are at 10 psi and 3000 rpms it will add "X" amount of fuel. now if you are at 10 psi at 6000 rpms it will still add "X" amount of fuel.

Now explain to me why thats not bad????

And to top it all of you dont have a wideband or any other way to even moniter whats going on....good idea, let us know how that turns out

It sounds like you already know what the problem is you just dont want to admit it ..."PROBLEM CAN BE CUZ THE CAR IS NOT YET TUNED THATS WHAT IM THINKING"....

take care of that then come ask us for help if its still acting up

 

yeah i mean thats what it seems to be coming down to, and i didnt mean any disrespect. i come here to learn its just that i felt like what he said was the DSM are no good and to throw away the FMU.. obviously im gonna get rid of it. YOUR explination was helpful tho.

 

back in the day when i ran a fmu with dsm 450cc injectors i had to cut the base fuel pressure in half otherwise its going to be way rich

 

well its going to a tuner pretty soon for that reason id rather go to the tuner having more fuel then needed then not having enough you know what i mean?

 

if your tuner is any good, he will tell u to ditch the FMU and just run the dsm 450cc. take out ur fmu, run the stock injectors ONLY to drive to ur tuner, swap out injectors to 450cc n tune

 

im gonna tow it to the tuner i really dont like how to car is driving.

i drove it for one day i didnt see past 4k rpm and im hoping i didnt crack and ring lands or screw the rings a bit or something