LEAN at idle! - Hyundai Performance Forums

rab71 · 05-27-2004, 10:42 PM

I don't understand. For months now, I have been battling gremlins in my car. I can't figure this out...

It is running massivley lean at idle!!! I don't know why! I have changed the O2 sensors, the injectors, the bypass valve, my BOV(turbo'd) The plugs, and checked over and over for vacuum leaks.

I don't know what to do anymore... Please, does anyone have any ideas?

Thanks
Rob:ermm:

MJBTV · 05-27-2004, 11:26 PM

MAF Sensor? Clean it. Computer is getting bad info on air flow and trying to adjust timing and fuel pressure to compensate.

rab71 · 05-28-2004, 12:00 AM

Oh yeah, I changed that too... I have three to choose from. Two X3 MAF's and one Beta1 MAF... Is their any way to check them? Also what do you clean them with? Soap and water? Or brake cleaner type stuff? Thanks for the input!

ROb

pare_john · 05-28-2004, 01:42 AM

are you using the Beta MAF? if you are try putting your X3 MAF back in. But first test it to make sure it is within spec.

is your car throwing a CEL? if so what is the code?

as for cleaning the MAF don't use brake cleaner. it is not sensor safe. they have sensor cleaners that you just spray on. Don't use compressed air that wil hurt the sensor. Also make sure that you have your MAF pointing in the right direction. there is a little arrow that shows which way it should go.

also is you IAT installed properly?

rab71 · 05-28-2004, 11:34 AM

I have tried both the beta1, and my X3 MAF... As for the IAT, it is dangling in the wind... It has ALWAYS been dangling in the wind. Ever since the first time I put on a CAI. But now, I am turbo(been for a while with no problems till' rescently) No codes as of late, but when I did get a code it was 1127 (over rich... yeah that make sense) I have changed my O2 sensors, to the ones from my parts car. My down stream O2 sensor was CRACKED! Dunno... I am going to check the wiring for my MAF, I had to extend my wires to move it. I did solder everything. I just don't get it. When I first redid my turbo setup(new manifold and pipes etc.) it ran perfectly. Then I changed how my air intake to the turbo was, and thats when the problems started. Now I have changed it back, and still have the same problems...:ermm::cry:

I am seriously considering getting rid of the car... And starting with something new...

Thanks for the help, any more ideas?
Rob

stickshift · 05-28-2004, 11:49 AM

How do you now it's running lean? Do you have an a/f gauge?
How's the air/fuel ratio at higher revs?

grimmy · 05-28-2004, 02:38 PM

detonation usually denotes a lean mixture, if an a/f gauge is not present.

Stock fuel pressure on the X3 is 44.3 psi per webtech. Turbo app. pressure should be higher - at 44.3 or slightly better at stock by figuring.

-Grimmy

rab71 · 05-29-2004, 05:25 PM

Yes I have an air/fuel gauge.... By the way, I fixed the lean problem at idle. It was the MAF, or at very least the connection... I out the beta1 MAF back on. Now it is just lean under boost... Starts around 7 psi... I have Beta1 injectors, and I have run this much boost before. I am wondering if it isnt my RRFPR... But it doesnt seem to be running lean under boost any more, so that would be a timing issue... I also have 36lb injuectors I am going to try... I have a new up stream O2 sensor comming now too, cuz I thought they were bad, so I might as well use it... First I will try the injectors, or buy and MSD ignition. We'll see...

Thanks for your help... If any more ideas please post..

Rob