New 750 injectors now runs crazy rich

[godfather75]

I just finished a fresh stock rebuild.I upgraded to 272cams and 750 injectors,I set my maf translator according to there instructions and now the car runs so rich it clouds the whole garage.I changed back to stock injectors and everything runs fine.What could it be the injectors are brand new fuel injector clinics.I haven't changed the fuel pump yet but have one just wanted to break it in before I changed it.

 

[freeman 188]

you need something to control these injectors and the maft translator isn,t a good way to try and do it . dsmlink or maybe a keydiver chip .

 

[jrohner]

Did you compensate for the injector size change?

 

[godfather75]

I set the translator for 750,I even tried to go leaner by setting it to a bigger injector.I rechecked it about a thousand times with the maf manual.Could it be that I don't have enough fuel pressure,I haven't installed my pump or afr yet?Also I removed the fiav and blocked it off.

 

[rEclipserGST]

How about doing it all at once??? It makes sense to try and tune fuel mods all at the same time. Not to mention... your going to use it ANYWAY. So try that and get a fuel controller or something. Doesnt the MAFT just control the amount of Air and NOT controlling the pulsing of the injectors? If thats the case, thats the reason your running to rich. Your injectors are staying open the same amount of time but the injectors are bigger so more fuel is entering. Telling it more or less air wont make a correct tune at idle because the ECU still thinks there are 450s in there.


Fix it.

Wideband, Fuel Controller, Bigger Fuel pump.

 

[godfather75]

I'm kinda out of money(no job unemployment).I thought the whole purpose of the maf translator was to compensate for different fuel injectors.

 

[godfather75]

I just read up on the neo and it does the same thing adjust fuel curve by air.The maf translotor says you don't need safc when using it.It does the same thing.

 

[muckerpuck]

I'm kinda out of money(no job unemployment).I thought the whole purpose of the maf translator was to compensate for different fuel injectors.

No, fuel injectors need a AFC-Air fuel controller, or An Ems-Engine managment system . Or a Pcm Tuner like Dsm link.

 

[Colt4G63 also]

I know, it sucks not having the cash to do the mods you need, but if you're going to try to tune with the larger injectors you need to get a wideband (and log it).

If you want to tune it to run on the street, you'll probably need more than a MAFT as well.

 

[zhjiln]

How about doing it all at once??? It makes sense to try and tune fuel mods all at the same time. Not to mention... your going to use it ANYWAY. So try that and get a fuel controller or something. Doesnt the MAFT just control the amount of Air and NOT controlling the pulsing of the injectors? If thats the case, thats the reason your running to rich. Your injectors are staying open the same amount of time but the injectors are bigger so more fuel is entering. Telling it more or less air wont make a correct tune at idle because the ECU still thinks there are 450s in there.


Fix it.

Wideband, Fuel Controller, Bigger Fuel pump.

actually that is the only way to tune with the MAFT and SAFC ...and they work great by changing the values of the incoming air flow.... thus you can compensate for bigger injectors... the OP just needs to get the right settings down....

 

[godfather75]

I've got a pocket logger but can't keep the car running long enough to get any info.I can hardly get it started with the 750s in,I gotta keep it floored.

 

[jrohner]

if you're going to try to tune with the larger injectors you need to get a wideband (and log it).

It's nice to have a wideband, but I wouldn't say it's necessary.

 

[snowborder714]

What do you tune with then if you don't use a wideband?

 

[banshee04]

If i can recall, when I put my 750cc Inj in, I set the AUX to 2.

 

[godfather75]

I'm running the stock injectors for now.I really haven't had to tune much only running 15lbs of boost.I just go off my fuel trims.It just bothers me that yet I have to buy somthing else just to make injectors work.I just bought a new fuel pump and afr.

 

[7"exhaust_tip]

Maybe you should slow down and take a look at the "upgrade path" or something...

 

[selmerguy]

You sir need to read more. 650's are about as high as you can go with a maft. For these cars they are really a waste of money unless you use dsmlink. I would check out dsmap if you have or can get a eprom. you can sell your translator and pay for dsmap and you get control ov everything. Moats ostrich is only like 150 I bet you paid about that for the translator. The only person you should be mad at is yourself for buying injectors tht are really to big for you tuning system. Good luck.

 

[godfather75]

Im not gonna be mad at my self I didn't post here to be ridiculed mr perfect.Slowboy sold me the setup to go with there 60trim turbo.I plan on getting DSMlink thanks for your help.

 

[toofast82]

750cc is a little too much for the MafT to compensate properly. Did you try to tune your fuel trims at though? I would recommend getting a wideband as soon as possible. Work on getting a eprom chip for the 750cc so you can use the translator effectively.

 

[tkelly27]

If you want to keep your MAFT, you could try burning yourself a chip to compensate for injectors

hwnd.org - 1G DSM EPROM Editing

Or go with speed density which can also compensate for injectors

http://www.dsmtuners.com/forums/tun...l-free-speed-density-tuning-software-1gs.html

And if you are unemployed I'd consider DSMlink a last resort. @ $600 it's not going to offer you anything the other two can't already do for the cost of an eprom burner and a few eproms (~$40 on ebay) or an ostrich and speed density sensors will (~$200-$250). Link is plug and play, the others you need to learn, that's the only bad part really.

Good idea to stick with the stock injectors until you get it all figured out.

Before wideband O2's were popular people were still able to tune. Not as safely or efficiently. Guy on the board here just ran 12.3 @ 118 with an EIII, AFC, 2G mas, and bigger injectors.

 

[godfather75]

I might try and get a chip and wide band also.Just breaking it in now so I have some time I might look in to speed density sound like a good setup,Thanks.