# SR20DET Running Extremely Lean at idle **URL:** \ **Category:** SON240sx Automotive\ **Created:** [January 12, 2014, 6:26am UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502 "2014-01-12T06:26:11Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![92NISSAN240SX](https://avatars.discourse-cdn.com/v4/letter/9/8c91f0/32.png) [@92NISSAN240SX](https://forums.speedlife.net/u/92NISSAN240SX)\ **Post date:** [January 12, 2014, 6:26am UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502/1 "2014-01-12T06:26:11Z")
Problem Actually solved completely running as of today, disregard all other posts Problem ended up being the fuel injector seals were leaking, due to the aftermarket intake I bought. One of the seal seats was to large and cause a leak only below 1000 rpm, also causes slight misfires at idle and while revving Problem not solved, I can hear a hissing noise right before the car dies near the intake manifold, I just replaced the injector seals NOTE: YESTERDAY IT WAS RUNNING AT 14.0 AFR Well I just got my car started after almost 2 months of tinkering, ended up being the battery was to low and not providing enough current. BUT NOW! I am running extrememly lean at idle ( i cannot drive the car it is brutal ) 18:1 + when i first start it up it runs fine sits perfectly between 14.5-15.2 @ around 1500 rpm, after a little bit the rpm comes down and then it runs very very very lean and starts to stall. Things I have replaced: Oxygen sensor Coolant Temp Sensor Battery injector cushsions (rubber seals on intake manifold) Wiring harness ( currently have a brand new wiring specialties one in ) Things I have tested: -Injectors ( they were recently sent out due to one of them leaking ) -Fuel pressure ( 3 bar ) - wondering if my fuel pressure gauge is wrong… Things I have checked: All my clamps, couplers and vacuum lines Reset Timing the proper way right now the ECU is showing three codes: Knock sensor ( code 34 ) Ignition signal ( code 21 ) CAS ( code 11 ) -\> just got this one Jan 15th thinking this is the culprit Any Ideas? ---
**Author:** ![sick96gst](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@sick96gst](https://forums.speedlife.net/u/sick96gst)\ **Post date:** [January 12, 2014, 7:17am UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502/2 "2014-01-12T07:17:14Z")
Start by checking for vacuum leaks, best way is to build a boost tester and pressure use the system. Do you have 3 bar fuel pressure while it’s running at 18:1? ---
**Author:** ![240sx\_nismo](https://avatars.discourse-cdn.com/v4/letter/2/3da27b/32.png) [@240sx\_nismo](https://forums.speedlife.net/u/240sx_nismo)\ **Post date:** [January 12, 2014, 10:17am UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502/3 "2014-01-12T10:17:51Z")
Is your bov vented out? ---
**Author:** ![GetARide](https://avatars.discourse-cdn.com/v4/letter/g/e495f1/32.png) [@GetARide](https://forums.speedlife.net/u/GetARide)\ **Post date:** [January 12, 2014, 2:41pm UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502/4 "2014-01-12T14:41:43Z")
Try clearing the codes and have a look again. ---
**Author:** ![92NISSAN240SX](https://avatars.discourse-cdn.com/v4/letter/9/8c91f0/32.png) [@92NISSAN240SX](https://forums.speedlife.net/u/92NISSAN240SX)\ **Post date:** [January 12, 2014, 8:23pm UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502/5 "2014-01-12T20:23:08Z")
ended up being a huge vacuum leak on the back of the brake booster line and the valve cover to intake tube. Idles nicely now at 14.4 - 15.1 afr Thanks guys 🙂 WRONG LOL, it runs fine for awhile at 14.7:1 but then it slowly goes to 18:1 and dies ---
**Author:** ![92NISSAN240SX](https://avatars.discourse-cdn.com/v4/letter/9/8c91f0/32.png) [@92NISSAN240SX](https://forums.speedlife.net/u/92NISSAN240SX)\ **Post date:** [January 13, 2014, 5:47pm UTC](https://forums.speedlife.net/t/sr20det-running-extremely-lean-at-idle/234502/6 "2014-01-13T17:47:48Z")
I have a boost leak tester I will have to pump up the system, The fuel pressure stays at around 36-38 psi with vaccum, I set the fpr to 3 bar