I know this topic has been discussed many times, but searching just didn't give me the answer i need.

I put the 850's in the primary and 1300s in the secondary. I udjusted the PFC like it said to 64.5% and .04m/s. That didn't seem to be only thing i had to do. For some reason it's still running rich as hell.

I went into the cell that was idling and leaned it out as much as i could, but that made no difference. Looks like PFC will only let you go down to 50 and that's it. It doesn't seem to have any problems running under boost or stuff like that, but the idle is really rich and it's killing me. You can see black fuel smoke coming out of the exhaust. Under 15psi the duty cycle i got is 62% Which seems to be fine for me.

I also tried playing with the screw under the elbow, but that made it worse.
I don't know what else to do here about this idle. Anybody have any suggestions on how to lean it out anymore?

The battery has been out of the car before i put the injectors in. Then when i connected it i made those changes. I haven't reset it yet. Do i have to do that?

Thanks guys.

Amel

 

Ttt

 

Aren't you supposed to get it tuned if you go past the basic mods and mess with the injectors or ignition

 

Has the PFC been tuned internally (with a Datalogit or a PowerExcel?)

You did reset the injector size in the PFC to 850/1300, right?

 

Yeah i did the injector part, however i didn't reset the ecu after i inputed all that. And Yeah the car was tuned with Datalogit prior to these injectors now.

Amel

 

You don't have to reset the PFC, most changes take effect immediately. You just have to turn the key off and on.

If the internal duty cycle map was modified, I would recommend taking it back to a tuner to have it retuned. IIRC those cells can be locked so that the PFC ignores your changes to the adjustment map.

 

You may also need to turn off idle O2 feedback - you're likely fighting it with those large injectors.

Dale

 

I turned that off as soon as i got PFC.

 

Did you mill the primary fuel rail down before you installed the 850's? 850's are shorter than 550's and won't seat properly if the primary fuel rail isn't modified to accept them. This would cause a very rich condition you are describing since there's extra fuel leaking into the engine past the injector o-rings.

 

There was no leak. I did the fuel pressure test and nothing was leaking. If it was leaking like you said, i wouldn't be able to start the car after 5-6 hours, because it would be flooded. I had that problem long time ago.

 

What's the injector duty cycle at idle? Also, what's your idle speed set at?

 

Duty cycle is at 4.0, 4.1 sometimes goes to 3.9. Idle is set at 930-40 without accessories and 980 with them.

Bare in mind that my engine has a heavy street port, so at those numbers is where it idles fine.

 

He didnt mean the injectors themselves would be leaking fuel out. The 850's are shorter than the 550's in which case the fuel is having to travel farther and not atomizing or whatever as good because the rail isnt milled down. The injectors are now farther away from the ports than they should be. That would be my guess also as to what your problem is.

 

Duty cycle sounds reasonable. I seem to remember mine dropping to like 3.5-4% when I changed to 850 primaries(5-5.5% w/ 550's).

Actually, I did mean leaking past the injector seals. Looks like BoOsTin FD pressure tested the injectors in the fuel rail so that possibility can be crossed out.
Hey, BoOsTin FD, did you mill the fuel rail down though? If you didn't, it's possible o-rings were just barely seated when you pressure tested, but leaking now.

How old are you injectors? Is it possible one of them is stuck open? When my friend had a stuck injector, it was spitting fuel out of the exhaust. I'm running out of ideas. Sorry...

 

I didn't mill it down, i put the extra o-ring. The injectors had 60k on them but were sent to RC for cleaning and balancing etc. They all came out great. I think that the problem is setting up PFC but i don't know what else to set other then the obvious.

Amel