Running lean and low idle

Howdy peeps, i have an issue you can hopefully help me with. I recently put an AEM AFR, a Blitz SBC-R ID3 boost controller and a HKS FCD on my vvti TT to finish my BPU. I thought it would be all an easier job to connect it all at once, probably should've done the FCD and BC separately. The issue is that once started the car leans out to 16.9-17.2. I thought it was as the ECU was re-learning idle but once it warmed up nothing happened. You can blip the throttle and it'll go safe but then return to lean. It also is idling around 450-550rpm which is low for a facelift. I didn't take it for a spin as i was afraid of running it like that.

Anyway i believe i have everything connected correctly.

• I hooked the FCD as per instructions on this site and the HKS manual giving me the correct wire to cut and connected the pos/neg both to the ECU as per HKS manual, its set to 9.
  
• I connected the the boost controller as per the MKIV.com (why isn't that site working right anymore?) sites instructions (capping off the VSV over the alternator, the pipe that runs from it to the top of the engine and also capped the bottom of the actuator). Connecting the IN to turbo 1 and OUT to the top of the actuator. Boost reading is taken from the boost pressure sensor tee'd off. I used all new (ebay) silicone pipes (3mm/6mm) and blanks (6mm) for it. Pipes to the solenoid are 2-2'.7" long. Power is taken from the cig lighter fused off along with the AEM AFR gauge.
  

Prior to this the car has been running fine with very good pull. It has had new coil pack connectors, IK22 spark plugs, a K&N drop in, 2.5" first decat, Whifbitz RR, 3" second decat and a 3" exhaust.

Updated on post 25

Have you replaced the o2 sensor? Could be that mate.

Sounds like you've connected the fcd up wrongly, we've seen this a lot ok the vvti's, disconnect it and see if it cures the problem.

Could be the HKS FCD is scaling the airflow signal rather than leaving it unchanged but clamping at about 4.4v.

Ill post up exactly how i connected it later today thanks peeps, it could be that im wrong lol. Would be like that to get everything else done and taken apart and the easy part i f*ck up lol.

So i checked and it seems to be the AFM mine is connected to as per the HKS manual pictured below (its "P" in the pic below). Looking in another thread though the MAP sensor is just to the right of this and is what someone else used. So is the HKS manual a f*ck up and should i change over to the MAP wire?

http://www.2jzgarage.com/wp-content/uploads/2012/01/Supra_2JZGTE_VVTi_ECU_Pinouts.pdf

Yes swap the wire over.

If you've plumbed it into the MAF instead of the MAP, then yes it'll cock things up if it's the HKS scaling-style FCD. Sounds like it is, the good news being a MAF based car is the only one that works properly with this FCD

Right only got around to tinkering with it tonight as i want to drive it for the weekend. I put the car back the way it was before the boost controller install and plugged the FCD back to original (power and ground still connected). No change so i took a pic of where the wideband sensor is placed in case its an issue, its on the second decat, a 3" Apexi. Im not sure if it should be in the exhaust flow like it is and if it may need an expander. Also it goes back to normal when i blip the throttle. Im still afraid to drive it jic. I also have a Blitz iVit connected to the OBD2 port and there is no issues with engine check lights.

This little/big ba$tard ran at me while i was taking the pic, i literally kicked him out of the shed and he was fine.

Right i haven't gotten around to doing work on this until a day ago due to a lot of personal issues cropping up, on a side note Kings College Hospital in London is a great place. Anyway i put the car back to standard (in the case of FCD and boost controller) and tested it and it was still the same. As per tonytt i did a quick inspection of the O2 sensor connection and i dont seem to have damaged it. Read the iVit OBD2 reader and it showed the O2 sensor running .02-.8v on warm idle which according to this site it should be .4-.8v and it its below it then it will run lean. Getting somewhere, anyway cleaned it and still the same. I provided a vid for people to chime in if im wrong. If not please let me know where i can get a proper O2 sensor as i want to use the car before the tax runs out at the end of the month! Cheers.

Sorry i also performed the rag test on the AEM wideband sensor to rule that out and it was fine, went fully rich to fully lean.

Do you still have the stock O2 sensor in place or you using just the AEM wideband?

Do you still have the stock O2 sensor in place or you using just the AEM wideband?

Wideband is just a guage being used for monitoring and safety. Any other suggestions before i buy a new OEM O2 sensor?

I bought a new O2 sensor for mine and it still idles low bud. My idle is around 400rpm

The thing that doesn't make sense and to me excludes the O2 sensor is the fact that you say from cold start it runs lean and doesn't change once warmed up, the O2 sensor is not used during warm up, so the AFRs should be rich, becoming progressively leaner until warmed up, not staying the same this would indicate another problem to me.

The thing that doesn't make sense and to me excludes the O2 sensor is the fact that you say from cold start it runs lean and doesn't change once warmed up, the O2 sensor is not used during warm up, so the AFRs should be rich, becoming progressively leaner until warmed up, not staying the same this would indicate another problem to me.

Sorry I should've been clearer, from cold starts it is fine (13-14afr) but as she warms up she runs towards lean which seems to be what you're saying. She still wouldn't be fully warm (by temperature guage) when she goes fully lean though..... I also took her for a spin (off boost) and she seemed to run fine without the tubbies except what the AFR guage was telling me lol.

So warm up is fine, but gradually getting leaner when warmed up, do the AFRs stay lean or do they vary? its still pointing to another problem to me as a faulty/failed O2 sensor will not normally show up as running rich AFRs due to the ECU fail safe.

My afrs are fine from cold start up running rich and as it gets warmer it drops to a very low idle. Changed the O2 sensor and made no difference. I thought it could be an air leak but the car boosts perfect and pulls hard. I'm at the stage now where I'm just going to turn the idle screw at the throttle cable so it's slightly higher. I've no idea at all why it's running low on idle as far as mine is concerned. TuneR hope you get to the bottom of it mate.

Just to check your not t ing off the vac pipe from the fuel pressure regulator on the inlet manifold, been told big no no and can cause problems

Just to check your not t ing off the vac pipe from the fuel pressure regulator on the inlet manifold, been told big no no and can cause problems

Nope, Map? Green sensor on inlet is tee'd off for boost gauge reading. Anyway have some watchmakers screwdrivers to make sure any connectors haven't gotten loose.

Only other thing I could've done to cause it.

I always make sure MAP and fuel regulators have there own feeds, two of the most important connections

I always make sure MAP and fuel regulators have there own feeds, two of the most important connections

Straight 12v? What about the fuel pump too? Pity i dont have a fuel pressure gauge, might get one if i still cant sort it.

Straight 12v? What about the fuel pump too? Pity i dont have a fuel pressure gauge, might get one if i still cant sort it.

I was referring to vac feed from the inlet manifold.

I was referring to vac feed from the inlet manifold.

Ill take a pic of what i've done with it later but iirc i basically tee'd off just below the turbo pressure sensor....

Im afraid i never got around to sorting this until now as i want to use the car soon and i had to get another car ready for sale. Anyway i have looked at it again. It stays fine until the oxygen sensor warms up and then idles lean. I decided to test it at boost for the first time and she pulls just fine (i missed that so much!). It goes from lean to normal and then waaay rich on full boost with the second turbo (i didn't get boost figure). Idle only went to about 450rpm once and that was normal driving before full boost.

This is how she stands atm, no FCD connected. AEM AFR connected to the Apexi second decat in the hole provided. The boost controller is hooked up as the following pictures show:

3mm silicone pipe connected to the boost pressure sensor on intake manifold using a y tee to get a boost reading.

Boost solenoid connected using the method found on MKIV.com. I used 6mm silicone pipes (less than the max length) and stoppers with clamps on them.

So far i have no solution so im going to put in a cat and have an emissions test done to see how the lamda reading is (this also needs to be done anyway for the NCT test). Afterwards ill decide whether to replace the O2 sensor and hope there isn't another sensor gone too but we'll see. If anyone else has any ideas feel free to post, cheers.