Derex'8

iTrader: (4)

Okay this has been an ongoing problem for about 11mos now. I even had the engine replaced, (not because of the issue but because I blew a seal) and I'm still having the same exact idle issues. That right there tells me, it is one of the components that were swapped from the old engine and put on the new one. I've ruled out any kind of vac leaks and the symptons don't indicate a improperly functioning MAF housing period.

My idle will jump from 500 - to around 1200 rpm back & fourth & then sometimes it will eventually stall, and in any kind of sustained heavy load conditions it goes completely rich, driving up hills you can watch the AFRs slowly start creeping up (Richer) and once I hit about 2 psi It'll go stupid rich as well.

Swapped OEM coils for BHR kit
Replaced all plugs
Checked & rechecked over & over for Vacuum leak
Fixed crossed fuel injector wires
I've replaced the MAF
Rplaced front 02 sensor
I have tried several different MAF configurations & still same result
Replaced turbo with Garret unit
Replaced blown cat with midpipe

11/8/09: Had all injectors Clean & Flow Tested & Replaced all Seals
KG Parts paperwork states my stock yellow injectors flow 440cc not 380cc. Not quite sure how relevant this is but my tune is for 380 injectors in the P1 & P2 position



The only thing I'm left with now is either I have a clogged, malfunctioning, or leaking injector.

What are you guys suggestions?

Please need advice

Derex'8

iTrader: (4)

Need some advice here fellas?

invasion08

iTrader: (7)

How many miles on the car? Put some fuel injector cleaner in and see what happens. I like BG44K. Also it could be your tune.

Brettus

iTrader: (2)

I'm leaning towards the intake setup . What are your LTFT's like ?

dannobre

iTrader: (3)

Give us a bit more info..Injector types/sizes, EMS..turbo etc....

MazdaManiac

iTrader: (3)

it still seems to me that you have incorrectly sized or mismatched injectors, or incorrectly positioned.

Derex'8

iTrader: (4)

I premix with Lucas UCL/Fuel injector cleaner

@ idle they fluctuate

Factory yellow 380cc injectors in the primary position, on the fuel rail that holds 4, I have the 2 yellows on the outside and the 750cc RC injectors on the inside. I'm using the Cobb Acessport w/MM calibrations

Unless all I've been told is a lie then I beyond a doubt have everything not only wired but positioned correctly. Oh and disregard that 1st bit about my car idling fine on the stock map, once I fixed those crossed fuel injector wires, put the coil connectors in the right order, and retightened a loose spark plug, I had the same issue across the board.

The car runs perfectly fine under normal conditions but once I apply some heavy load the AFRs start rising until it eventually bogs down, or if I'm cruising on the highway lets say @ about 68-72 mph and I hit a hill it will stumble, go completely rich until I'm on level ground or descending. and @ idle my tach just jumps back & fourth.

Could it be possible that maybe on or two of the injectors are possibly shorted or not working because I did have the wires to the 750 injectors crossed & just noticed it last week. After installing them almost 11mos ago.

dannobre

iTrader: (3)

Are the RC 780's low or high impedance injectors??

Derex'8

iTrader: (4)

Oh SNAP!!! I just went to check their site to find out what impedance they were and I saw this; I have the 750cc installed in the P2 position!!! So this is probably the problem anybody have any explanation to why they're only compatible in the secondary position.

Oh & they are high resistance...

dannobre

iTrader: (3)

Might not be able to scale them properly? I can't see why not though....If they fit it`s not the size

Secondary would be a better position though...they are much more useful there...

The high impedance is a good thing

Derex'8

iTrader: (4)

Well I'm a have my mechanic swap the injectors and while he's at it go ahead and replace all the seals & o rings

dannobre

iTrader: (3)

You are going to need an alteration to your tune as well..............

Can`t just chuck them in there and expect them to work

What EMS Access Port......

Brettus

iTrader: (2)

I assume you had MM supply a tune for that exact injector setup ?

Derex'8

iTrader: (4)

Yup jeff supplies my maps, but looks like I'm back @ square one. Was informed not to swap those injectors in the secondary and to do so was a bad idea, as those injectors would not even come on till about 3800+ rpm.

I guess I just need to hook up a pressure gauge and check for either clogging or leakage per FSM.

Brettus

iTrader: (2)

kinda looks like something funky with the injectors allright but just to eliminate easy stuff - what does your intake look like ?

Derex'8

iTrader: (4)

3.5" 90 DEGREE PIPE from turbo inlet w/screens to eliminate compressor turbulence, then a 3.5" maf housing roughly 6-7" long w/a screen pre Maf and then a 3.5" 45 degree pipe exiting out the engine bay, where oem vfad is located.

so 45 degree pipe, maf housing, and 90 degree pipe to compressor.

Brettus

iTrader: (2)

that does sound like it could be problematic if not 100% . Why did you say you could rule out the maf housing in your first post ?

Derex'8

iTrader: (4)

IDK, just from what I have experienced myself and have seen from others. When watching my maf on the AP the numbers are not erratic, they are fairly nsync with throttle response and load. I will post a picture of my setup and a datalog, maybe that will help narrow things down

Brettus

iTrader: (2)

/\ good idea .
Do a chart showing maf , afr , rpm , timing , throttle posn. and load

something like this would help .....

MazdaManiac

iTrader: (3)

Incorrect.

The secondary intake runners only see airflow some of the time, so the injectors there would only be useful above 3800 RPM.
A well-designed turbo system will see boost WAY before that.

The P2s are in the same runner as the primaries, so they always see air.

Huh?
Your "11 Deadly Questions" say you have a stock MAF housing, which is 3.375".

Derex'8

iTrader: (4)

Yup I do have a stock maf housing w/the rest of the intake 3.5" OD, not ID.

I've also forgot to mention that I'm also experiencing a strong fume odor inside the cabin whenever I turn the A/C to blow from outside.

I just went ahead and sent off my injectors to KG anyway
I'm refreshing all the fuel injectors and ordered new seals & orings. I'm going to also rearrange my setup & use an actual wire harness adaptor vs. splicing in.

My new setup will be;

380cc Primary 1
650cc Primary 2
750cc Secondary

Brettus

iTrader: (2)

/\ jeebus that is a lot of fuel - You plan on makeing 500whp ?

Derex'8

iTrader: (4)

Damn it I don't know what to do. Received my injectors back from KG parts today and reinstalled them back to my original setup, (for the time being until I can get a new startup Calibration). I start her up and after warming up it still does the same damn thing but not as bad. I also seafomed the engine while I was at it. Maybe I need to let the car settle in or something but as of right now I still have the same symptons but not as severe.

The sheets I received back from KG parts state my stock yellow injectors flow
440cc not 380cc, could this possibly be my problem? Because my calibration is for 380 injectors in the P1 & P2 position

Brettus

iTrader: (2)

just a heads up
im using 280/380/480 injector combo making 330whp . Why do you need all that fuel you have there ?

MazdaManiac

iTrader: (3)

uh, yeah. WTF?
A 15% increase in fuel at the P1 is MASSIVE.