Unusual engine idle surge/running lean 6k rpm+ ESS650

[E92///]

Running a 650 ESS supercharger kit with a ESS tune for 4k miles and 84k on the motor all original besides new rod bearings, spark plugs, ignition coils, rear drive shaft and new battery. The car typically idle's at -20 vacum (ps3 guage). However after driving the car hard on the highway I noticed unusual idling while parked. The rpms began kicking from normally approx. 500ish to 1000 as if someone was pressing on the gas pedal on and off and vacum dropped to -14. Pressing on the gas pedal and goes away. Then drove again parked at idle while engine was running and the car was fine for few minutes and started again. This is happening at about half a tank of gas. I did also notice the rpms surging upon filling a full tank of gas. Again it would go away after pressing on the gas pedal a few times and not notice it again until the next refill.

I have no codes for actuators or cel. idle control valve? actuators?

NEW UPDATE: 5/1-2020

Did a dyno run at Turner Motorsports and they stated that at 6K rpm the car started running lean and at 7K vibration and losing power/rough. Made 550hp and was not safe to test further. Sent over the dyno log sheet to ESS and hoping to get some direction on this. Not sure if its S/C kit related or tune...or mechanical.

5/4
Engine shut off while idiling after filling up on a full tank of gas. This is the first occurrence, however idle surging has been present for a while but goes away quickly after. I wouldn't be looking into this if it wasn't for the Dyno results the Lambda is at 0.93 (13.7:1) at 7000 rpm, which seems to be very lean.



Thanks in advance for your help!

[bvrider1]

on cold start what does your vac read at? Also what psi are you getting? Assuming you are running a p3 gauge?

Have you checked for leaks in the throttle body intake boots?

[E92///]

Originally Posted by bvrider1

on cold start what does your vac read at? Also what psi are you getting? Assuming you are running a p3 gauge?

Have you checked for leaks in the throttle body intake boots?

14 15 warms up and gets to 20

[E92///]

NEW UPDATE: 5/1-2020

Did a dyno run at Turner Motorsports and they stated that at 6K rpm the car started running lean and at 7K vibration and losing power/rough. Made 550hp and was not safe to test further. Sent over the dyno log sheet to ESS and hoping to get some direction on this. Not sure if its S/C kit related or tune...or mechanical.

[darkbmw]

Weak fuel pump