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General Category => Engine Management => Topic started by: marcj on June 18, 2009, 10:15:56 PM

Title: 780cc injectors.. halp
Post by: marcj on June 18, 2009, 10:15:56 PM
I know I've been posting a lot of problem threads lately.. more than any single user should ever have in 1 week, but i'm having bad luck this past week.

Alright, I finally got my 780cc injectors in and sealed (fuel rail studs stripped out on me), and now I'm having a problem getting the new injectors to idle. I spoke to a friend that tunes cars, and he told me to use my tune from the 450cc's that ran my car perfect, and just change the injector size in the settings, which will change the multiplier. 

I made a map today that went lean in boost, and broke up.. scared the shit out of me and I don't want to mess with the tune again until I have a solid basemap. any suggestions??
Title: Re: 780cc injectors.. halp
Post by: ryan89crx on June 18, 2009, 10:22:56 PM
do what your friend said. use your old map and change the injector scaling. then adjust the injector fuel multiplier to get the idle/part throttle close and fine tune from there
Title: Re: 780cc injectors.. halp
Post by: bouncinofftherevlimiter on June 18, 2009, 10:24:13 PM
could you try upping the compressor efficiency if you are using crome? my basemap went lean in boost and i upped that and it seemed to help alot. dont know if that is the correct answer but it could be a place to start.

i kept upping that in my basemap till a majority of it was close to 11:1 or so and then fine tuned the other spots.

not to hijack but is that how the CE is supposed to be used. i ended up at around 210% to get it in the right range for my car.


 
Title: Re: 780cc injectors.. halp
Post by: ratcityrex on June 19, 2009, 12:50:14 AM
What ems system u running? Crome? ectune? turboedit?
Title: Re: 780cc injectors.. halp
Post by: marcj on June 19, 2009, 09:05:27 AM
crome pro
Title: Re: 780cc injectors.. halp
Post by: ratcityrex on June 19, 2009, 10:12:52 AM
Whats your setup? My b18a idles like a champ with my 750cc injectors on crome free.
Title: Re: 780cc injectors.. halp
Post by: BoostForLife on June 19, 2009, 11:23:32 AM
Whats your setup? My b18a idles like a champ with my 750cc injectors on crome free.
http://www.realhomemadeturbo.com/forum/index.php?topic=3493.0 (http://www.realhomemadeturbo.com/forum/index.php?topic=3493.0)
Title: Re: 780cc injectors.. halp
Post by: marcj on June 19, 2009, 11:27:12 AM
i'm having crazy problems with this shit. I tuned multiple configurations with my 450's, but these new injectors are kicking my ass.. i'm starting to think a problem is elsewhere. 

the 10watt 10ohm resistors work with all peak & hold injectors?

can someone make me a basemap? maybe i'm doing something wrong here.
Title: Re: 780cc injectors.. halp
Post by: Joseph Davis on June 19, 2009, 12:04:09 PM
One basemap is as good as another, you need to tune what you have.
Title: Re: 780cc injectors.. halp
Post by: ifly87 on July 08, 2009, 03:11:09 AM
When I start tune with larger injectors (like 550's and up), I make a fresh basemap, then change the injector scaling, you know.... old-240 new-750 (or whatever). Then add fuel tools, start the car and adjust the offset under the advanced tab of the fuel multiplier window. Then if it still idles goofy I just use the generic injecor battery offset values in the "more" drop down menu of the injecot battery offset (stock) in the advance tables.
Title: Re: 780cc injectors.. halp
Post by: d-rail on July 08, 2009, 06:05:43 AM
You need a quardrajunk carb that's bored out to 4000 cfm with a lead float in the bowl to make sure you always get awesome amounts of fuel but still get 59 mpg
Title: Re: 780cc injectors.. halp
Post by: onlyflash944 on July 08, 2009, 02:21:46 PM
You need a quardrajunk carb that's bored out to 4000 cfm with a lead float in the bowl to make sure you always get awesome amounts of fuel but still get 59 mpg

clown, stfu





i'm no tooner, but the larger injectors will probably need alittel fine tuned after you scale them up from the 450s.  thats because even tho the math is right, the injectors are made a bit different because of the difference in size
Title: Re: 780cc injectors.. halp
Post by: jagojon3 on July 08, 2009, 02:35:54 PM
I don't understand what the problem is? You said that your map is lean in boost, so add fuel. You might have to mess with the injector battery offset values as well so do that first.

edit: Just re-read about the idle issue. Have you tried changing your crank and post fuel multipliers? Injector offsets as previously mentioned can also affect this.
Title: Re: 780cc injectors.. halp
Post by: marcj on July 11, 2009, 11:10:29 PM
i'm undergoing many revisions to my projects right now. these injectors are now going in my 240sx and 450cc's are going back in my coupe along with my old tune that runs perfectly. thanks for all your help though