I just got my Stage two FMIC upgrade on, and my car idles really rough now. So I thought its time to get some new injectors, with a calibration kit.

I called Hahn and asked for the stage two injectors which are only 26 # or 270cc. My question is isnt 270cc too little for running
8 PSI? should I get anything more than that?

BTW this is what the Hahn guy said on email:

"Not at all, as remember the more fuel pressure put through the injector the more fuel it sprays. Doubling the fuel pressure from say 40 to 80psi will make a 270cc injector like a 500cc injector size wise. These are good to 14psi with a built motor.
Thanks
-----Original Message-----"

My car's Mod:
hahn stage 2 FMIC kit
afc-2 (untuned)
stock internals
msd coil and ignition with new plugs

I ran 8 psi on stock injectors. 270's are fine.

Anything bigger than stock. 110 PSI of fuel at the rail with stock injectors is not cool.

Get some 440's an SFMU and call it a day.

hahn has a recalibration kit to put in their cartech unit for the 270cc injectors
so the pressure doesnt go as high as it would without the kit

Originally posted by baxsom
hahn has a recalibration kit to put in their cartech unit for the 270cc injectors so the pressure doesnt go as high as it would without the kit

The problem being that the POS Cartech is still being used. SFMU or bust. But then again, in the Cartech's defense, maybe it works better at lower fuel pressures. I only worked with it when I was running Stage 2 out of the box and I couldn't get it to keep the desired fuel pressure. :shrug

The thing about the Cartech is that it's a Fuel Pressure Riser, not a Fuel Pressure Regulator. That is why it has problems keeping the same fuel pressure from day to day. It needs to be used in conjunction with some other kind of regulator which maintains your idle fuel pressure.

Yeah, that's my point. Why bother when an SFMU will do exactly what you need it to do and you can drive worry free.

your car is not idling rough because your stage 2 with a front mount intercooler??? im running 10psi on stock injectors with a regular fmu if i try to go above 10 psi i get fuel cut but anything lower im fine. if your car idles fine before adding the stage 2 kit id look to see what you did while installing cause to the best of my knowledge installing an intercooler should do nothing to your idle unless there is a blockage in there somewhere. and you will only know if your injectors are not doing their job while under boost not at idle so im not sure your injectors have anything to do with your problem.

no no, my car is idling rought after i got my stage two kit on,
and my BOV sounds really different from before.

also, what is this FMU or SFMU or cartech that you are talking about?
is it a device that is included with the hahns kit?

Im not sure but i dont think the hahn kit comes with an fmu (fuel managment unit) it does but i dont believe its a vortech like the one we all use. but non the less what i was saying is going from stage 1- stage 2 should not effect your idle, not that i know of?? someone help me out here, as for your bov sounding different thats possible cause your now pushing added boost, and its intercooled. This is the reason i decided to customize my turbo kit, i used mostly hahn equipment but a different fmu,fuel pump, and bov.

Do I have to adjust my fuel pressure after I put on the stage two kit? could that be the thing affecting idle?

Im gonna say no, for the simple reason all you added was a device to cool the air down a bit (intercooler) im assuming since its hahn you also went from a 5lb actuator to a 10lb actuator and a few pipes to connect it all together? unless im seriously missing something here its as simple as that, what you did should not have changed the way your car idles?? now im not an expert on this whole turbo thing but ive got a year hands on an 2 years on top of that in the books, hahns kit does come with a different fuel set up as mine so there might be a chance you need to adjust fuel pressure but i doubt it and even if you did have to i really dont see where it would matter at idle. im gonna research what all comes with the stage 2 upgrade kit and see what is causeing your issue cause this is getting to me now, i could only imagine how you must be feeling, it just doesnt make sence to me??? ill be intouch, and btw this post should really have been in the turbo section
joe

The "stage two" is just a intercooler and pipes right? If so this should not effect your idle at all. Did you make sure the pipes and intercooler were clean? Did you take the plugs out of the intercooler in and outlets? I think hahn sends them blocked off. I heard another person on this site that did not take them out and had trouble. A motor wont run well with out air you know.

Ok im back, well after looking at what all is involved with the stage 1 to stage 2 kit i still stand my ground on what i said before there should be no reason why you are having a change at idle, i also read the hrc install instructions as wekk again and all it says is that when you first install kit you set the regulator at a certin setting i think like 45psi at idle or something, this you would have done with the initial install and to the best of my knowledge should not change when you upgrade to stage 2? again your idle issue is not related to your new upgrade, retrace your steps and you might find your problem. When you finsd out what it is let me know id love to see what it was
joe

Originally posted by joeck76
Ok im back, well after looking at what all is involved with the stage 1 to stage 2 kit i still stand my ground on what i said before there should be no reason why you are having a change at idle, i also read the hrc install instructions as wekk again and all it says is that when you first install kit you set the regulator at a certin setting i think like 45psi at idle or something, this you would have done with the initial install and to the best of my knowledge should not change when you upgrade to stage 2? again your idle issue is not related to your new upgrade, retrace your steps and you might find your problem. When you finsd out what it is let me know id love to see what it was joe

The kit came with a 8psi actuator to replace my 5psi actuautor, so that might messed with fuel pressure. I had this kit professionally installed for me, so I mite take it back to have them check it out.

I see what your saying and although hahn claims its an 8lb actuator its actually an 8-10 pound actuator and this part will do nothing to your idle, your not understanding what im saying and i see now why, you didnt install it someone else did, now that you mentioned that i would definatly tell you to take it back and have them fix what ever they messed up. to better explain to you what i mean, you telling me installing an intercooler and 8 lb actuator messed with your idle is like me telling you me changing my wiper blades messed with my idle, one thing has nothing to do with the other. take it back and have them fix what ever they done wrong , could be as simple as a vac line but somethings not right for sure.

it turns out that, my mechinic tuned my S-afc2, and thats what caused my idle to be rough, but the car really runs fine under full boost or little boost... so that solves that. Thanks for all the help guys!!

I do plan to upgrade my injectors but what size should i run anyways? (for 8 pounds)

and I really dont know what is all that carfax crap and fmu and smuf

It is simply weird to have the car run rough after a intercooler upgrade, unless your fuel system was not re-adjusted for the additional boost that a stage 2 kit runs.

Just as a precaution, check yor compression.

are you serious about not knowing what a Cartech or FMU/SFMU functions?

Originally posted by eclipsekaiser
It is simply weird to have the car run rough after a intercooler upgrade, unless your fuel system was not re-adjusted for the additional boost that a stage 2 kit runs. Just as a precaution, check yor compression. are you serious about not knowing what a Cartech or FMU/SFMU functions?

This is only true under boost conditions not at idle. his problem is at idle, so there should be no adjustments needed, idle fp should be the same unless you changed injectors or fmu? according to him all that was done was an intercooler and a 8lb actuator, neither of these two mess with idle fuel pressure.

He did not specifically indicate the car was boosted after the stage 2 upgrade. If for some strange reason the car was driven hard by either him or the shop without carefully monitoring the EGT/Fuel pressure, the chance of a cracked ringland is likely a contributing factor to the rough idle. Beside, if he is running the Cartech, he needs to readjust his fuel pressure... Just ask all HRC users that made the switch to SFMU.


"Not at all, as remember the more fuel pressure put through the injector the more fuel it sprays. Doubling the fuel pressure from say 40 to 80psi will make a 270cc injector like a 500cc injector size wise. These are good to 14psi with a built motor.
Thanks"

- if you believe this shit, you deserve to have a rough idle.

i agree with you on the quote, that was a bunch a bull that hahn told him , however i still dont see where putting an intercooler and 8lb actuator on a car will affect the idle? this is what the whole argument is about, no matter what the case my be, he said his idle is messed up, never mentioned anything about running the car, boostin or anything, i know you need to re adjust the fuel pressure but that will only affect while under boost it will not do a thing to the idle initally. the way i read it was he installed an intercooler and higher actuator cranked it up and it idled funny, to me thats crazy cause one thing has nothing to do with the other. but than he mentioned someone else did the work that changes everything cause like you said anything could have happened from point a- point b. all i know is his rough idle is not related to the actuator or intercooler initally! whatever happened after it was all installed started and tested i dont know but an intercooler will not mess with your idle, you did or they did something else.
joe

P.S this is exatly what was said "I just got my Stage two FMIC upgrade on, and my car idles really rough now. So I thought its time to get some new injectors, with a calibration kit."
i guess the first response should have been more info needed