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-   -   430cc injectors to[o] big? (https://www.miataturbo.net/e-manage-10/430cc-injectors-%5Bo%5D-big-33916/)

94blackmx5 04-12-2009 10:49 AM

430cc injectors to[o] big?
 
i have an emanage blue right now so i can only tune my fuel down 50% of stock size so i would be flowing 287cc's at idle. that's really not a huge difference over stock. my car is a 94 obd1 1.8.
Thanks

Aricjm15 04-12-2009 11:41 AM

The don't flow full open at idle. 50% might be all you need to get a decent idle since they are just a tad larger then twice the size of OEM injectors.

94blackmx5 04-12-2009 12:15 PM

that's what i was hopeing. the only problem with the emb is with injector correction you can only add half of your stock injector size. so to run them i would have to make my stock injector size 287cc and the corrected size 430cc. i really need a clean idle though. i would be willing to idle the car at 850-900rpms if needed

elderc 04-12-2009 12:34 PM

I use to run 460cc with my EMB using the injection correction factor 265cc-460cc
more than 50%. The car would idle fine A/F 14.5 @850 rpm. the trouble you will find is that when triming fuel beyond 50% it will effect your timing (advances it) you will have to pull timing to keep down knock.......... but it can be done if your willing to spend the time.

94blackmx5 04-12-2009 02:21 PM

thanks for the reply. i haven't seen you on the emanage forum for while. my timing is at 14 btc right now i haven't boosted the car yet still gathering parts. what if i just left it at that under idle and then pulled back pretty far down to like 4 btc under full boost. i only plan to run about 8 psi

elderc 04-12-2009 02:29 PM

At 8psi I was pulling -6 from a base timing of +12 A/F 11.00 with no knock I don't know about +14 , just give a try if it knocks pull some timing.

messiahx 04-12-2009 02:59 PM

I'm confused here...is there more of an adjustment you can do do with the EMB than just entering in the correction factor (265cc / 330cc in my case)? My car idles a bit rough right now and I don't know of any way to fix that except maybe increasing idle speed. Off idle it is fine, however. Am I just dumb?

94blackmx5 04-12-2009 05:06 PM

try makeing your correction 255 and 330 see if that helps a little bit

elderc 04-12-2009 05:15 PM

The EMB should be able to control 330's with no trouble............idle issues maybe caused by something else ?

messiahx 04-12-2009 10:18 PM

It idled fine before swapping the 330's in. Seems rich now (exhaust smell is very strong). I'll look into it more tomorrow after work. I was under the assumption a rough idle was normal with larger injectors + EMB.

elderc 04-13-2009 08:11 AM

Not true about the idle ( in my case anyway) my RX-7 460's idle like stock,
but it advanced my timing too much, causing knock.
What are your A/F's at idle ? mine were in 14's .

messiahx 04-13-2009 12:55 PM

Don't know my A/F...I'm still N/A, so the wideband isn't installed (actually, begi is about 3 weeks late on my order :( ). I'm not hearing any knock at idle and the cars runs beautifully off idle. I expect a bit of flaming for no wideband and an injector swap now...but in my defense, they were just cleaned & flowed.

(just curious) When you say your timing is getting advanced, you're saying the EMB is doing that? That seems like a pretty weird behavior to be programmed in. Any idea why?

elderc 04-13-2009 03:36 PM

The stock ecu is advancing the timing. Because the EMB alters air flow meter signal to trick the ecu into thinking less air, the stock ecu thinks (less load means more timing), so as you go beyond the 50% size you will have to pull additional timing because the "stock ecu trys to advance it" because it thinks the load is less. .........thats why the EMU is better it does not need the MAF signal for control.

messiahx 04-13-2009 09:53 PM

That makes sense on the timing stuff. Also explains why so many are pro EMU or other MAP based ECUs. Oh well. Someday I'll make that jump.

Well I double checked everything on the emanage and around the fuel rail. Couldn't find any explanation. I forgot to mention that on warms starts, the enigne revs up and down a few times before settling into idle...it has died twice doing this.

I'm starting to wonder if the EMB wiring isn't right...I bought a boomslang since I don't know much about wiring and didn't want to hack up the stock harness. My only means of testing this is going to be adding copious amounts of fuel to see if I can't affect idle/how it runs since I can't measure AFRs. Blah. I doubt the wiring is the issue, though. The EMB can tell me the inj duty cycle, so I know it's getting something from the ECU. Btw, I do appreciate the feedback you've been providing. Taught me a couple things about the EMB I didn't know.

elderc 04-14-2009 08:55 AM

You can use a map sensor with your EMB through the boost port ( I'am using a E-bay Greddy knock-off 3bar. map sensor I got for $50.00) you can still log your A/F through your second Air Flow meter wire (with 3rd party software) which you don't use anyway, because Miata's use only 1 air flow meter. see link for 3rd party software : I'am also using a Boomslang harness never had any trouble, sounds to me like there maybe something else is wrong, maybe idle control valve ?

http://www.newcelica.org/forums/show...187913]Emanage Wideband O2-logging by Immo - NewCelica.org Forum[/url]

4sfed5 06-11-2009 06:43 AM

the emanage stops reducing the airflow adjustment at a certain point. with the 1600's its at 330cc if you input a bigger number than 330 no more adjustment is made to the afm voltage IT JUST STOPS AT THIS POINT.its just pointless. on the 1800's it may be a bit higher than this such as 360cc. but either way entering in 440 WILL not adjust the fuel correclty compared to entering 340cc

4sfed5 06-11-2009 06:48 AM

oh and if you need to remove even more fuel at idle than you need to look at the "clocking crystal" mod where you change the ecu's clocking crystal to a higher value (either 4.0Mhz to 4.4Mhz or 8.0Mhz to 8.8Mhz depending on model year) this will remove another 10% fuel from your oem ecu maps and advance your timing about 3 degrees.
OH AND IT WILL BUMP YOUR REV LIMIT BY 10% TOO! HEHE


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