AEM goes full lean at idle

[kinger]

Anybody else have this happen? The gauge just goes full lean at idle, I tried adding fuel with the gems just to see and it did nothing on the gauge but just made the sled stumble.

She purrs ar idle around 1100 rpm, so I need to increase the idle to get enough fuel to go through it?

Other then that it works perfect during WOT runs.

 

[TT]

x2

Mine has done this since it was brand new. It will go full lean when sled is warmed up and idles . Sled runs fine through all RPM ranges. AEM guage works fine as soon as I apply some throttle. I have a feeling that is caused by the sensor beeing located before the turbo (read too close). This is on a mcx rear mount setup.

 

[crippledncrazy]

I would try testing the o2 sensor before doing anything. Im not sure if you guys already read this or not but its worth a shot.

http://www.youtube.com/watch?v=1mb4VmDd0ao

 

[347strokin]

My AEM did the exact same at idle on my TNytro. I had it about 14" downstream of the turbo. Any throttle and it would start reading accurate again. But you can also test it out too.

 

[kinger]

I dont really care I guess just wondering if its normal? I dont spend much time idling so its not a big deal. I will test the sensor sometime, although its BRAND new.

 

[347strokin]

It is normal depending on the placement of the sensor. An exhaust leak can also cause weird readings.

 

[kinger]

FIXED! My exhaust was cracked, got it welded and she purs at 12.5-13 at idle now.

 

[gsxr]

camshaft overlap at idle will pull fresh air into the tailpipe and show lean (numbers) ,conditions, be happy !!!!!!!

 

[ProstockBenji]

probably the o2 sensor going bad . had it happen to one already same way .

 

[rxrider]

To my knowledge the GEMS box is not adding fuel until it sees 2 lbs of boost. It may not add any fuel at idle, I think. Glad you found the problem buddy

 

[insane]

My dynojet wideband commander does the same thing at idle. I put my bung on the can part of the exhaust and I believe that at idle the can gets flooded with air as there is not enough exhaust pressure. Just as soon as I hit the throttle it goes up to 13. I should have put the bung on the exhaust pipe, thought that the can would give a better reading because of all four cyl. are flowing through there. I just use my ear and watch the rpm to set idle. Is that safe?

 

[Ski-Dooin' it]

I have mine about 8" post turbo and had a leak in my flange on my downpipe, so it was leaking a little air in, blip the throttle and she comes right up to where its supposed to be.

 

[rxrider]

I was mistaken according to Mac at MPI, he's the programmer of the GEMS boxes. The GEMS start adding fuel at 0.5 lbs of boost.

 

[gsxr]

The Gems will switch on at a preprogramed point , Mac says .5 lbs but , bassed on program will only add a preset percentage of fuel at a given boost.

eg The 2010 xtx Gems was preset to add fuel from 1-11 lbs , minimal at 1-2 lbs , but then ramp up to max added at 11 lbs. ( a larger percentage from 2 lbs and so on , on a parabolic curve)

Since our mid range lean issuse , the Gems now adds fuel from 1-6 lbs(max fuel at 6) , the yellow is now active all the time , not timed as it was ( on 1 second only on previous program ) , allowing us to feed the middle.Works well.

 

[kinger]

In case everyone missed the post above my exhaust was cracked and leaking once fixed my AF gauge works now at idle.