Stumble under vacuum and super lean

[fireman2101]

So I just installed grey top 440's, robtune ecu and jecs maf last week. I go to drive my car last night and my wideband is going crazy at idle jumping from the 13 to 15 range and idling pretty rough. I drive it around and under light throttle the wideband is showing numbers in the high 16's and 17's. When I get it up to boost the a/f goes back down to 11's and it runs ok. I searched for a vacuum leak and couldn't find anything. Within the last week or so I have changed the plugs, wires, coil, fuel filter, and fuel pump. I am pretty stumped right now.
I recently have gone over most of the lines with starting fluid to try and find a leak but never found one. I can't find a leak in the intake.

Any ideas or insight would be helpfull. I have searched around but cant seem to find a fix.

[mike-tracy]

Do you have a robtune for 440cc injectors?

[fireman2101]

Do you have a robtune for 440cc injectors?

Yes or at least that's what I was told when I bought it.

[mike-tracy]

If you look at rob's eeprom chip on the ecu, it should have a sticker with the details of the tune, including the injectors size.

Sounds like you have a couple distinct problems going on, but it would be good to have assurance that you have the correct injectors for the tune.

[Legacy777]

I agree with Mike, my first recommendation would be to verify you truly do have a robtune ECU that is setup for 440's.

[fireman2101]

I'm going to double check it but after reading the forums I got intake gaskets, tb gasket, iac gasket, knock sensor and the coolant temp sensor and am in the process of replacing all of them. I'm sure 200,000 mile gaskets and 18lbs of boost don't get along so well so I'm just gonna do everything right now. Next step is I'm gonna pull the motor and rebuild the whole thing but the wife won't be to happy about that one and I really hope it doesn't come to that point yet.

[JDMSLIK]

When I did my swap I had a couple bad mafs. I don't know whats up with the wreckers I go to but we've had issues with used mafs out of there constant.
If your lean I'd try cleaning that maf.

[fireman2101]

I just got another maf yesterday actually. Gonna try and see if it helps. I found out that part of it was caused by a bad ignitor so I was only running on 2 channels out of the 4 from the ej20 ecu. That helped a lot but now I keep blowing intake parts apart.

[JDMSLIK]

Sounds like you got a monster vacuum leak. Does it start lean then go rich under boost? What intercooler are you using?

I made a tool like this to find my leak. I had the same thing, kept blowing the intercooler off. The silicone 90 degree was badly oil soaked and I didn't have any beads on the pipe.
http://forums.nasioc.com/forums/showthr ... ?t=2205161

[fireman2101]

Now it's jumps around the 15 mark on the wideband(was worse before) and goes rich under boost. I am using a 2004 wrx intercooler. It is running a lot better now. I think I may be slowly fixing problems as I go. I changed the intake gaskets, re-did the intake piping, changed most of the vacuum lines, re-gapped the plugs and keep going over things and it seems to be helping. I still want to adjust the tps, get a colder set of plugs and "adjust" the firewall a little more to fit the intercooler better to get a less turbulent flow but life keeps getting in the way.