07-02-2011, 04:03 PM
Join Date: May 2010
Total Cats: 1
What can cause me to be leaning out?
The car is tuned on an AEM F/IC piggyback with 305cc Supra green top injectors. Running about 10psi on my GT2554R. A few weeks ago the car ran like crap and would misfire. Today I finished putting on the test pipe, getting a recirculating blow off valve on, and fixing the leaving idle air control valve. I thought this might solve my problems (high hopes), but nope. The car run smoother now, but still lean.
I bought the car boosted and it would always have a steady 10.5-11 AFR in boost at WOT, but now it fluctuates around 12-15... obviously a bad thing. So what could cause this?
-Poorly gapped plugs?
-Bad O2 sensor?
-Bad crank angle sensor?
-Bad crank position sensor?
-Tune gone bad?
The car sometimes doesn't even turn over, I noticed this seems to happen after I fill up (maybe a coincidence). But if I let it sit for a minute or two, it'll start right up. It still randomly will run on what seems like 3 cylinders, but will correct itself. It's still good enough to daily drive, but I'm not sure what to do. I need to rule things out and check things that could be the culprit. I want to throw in some 550cc and MS, but not unless I can find someone to tune it or be sure it'll fix my problem.