tomlaw
Probationary Member
- 19
- 0
- Jun 15, 2007
-
Chicago,
Illinois
Please see my profile for upgrades. The motor was built (5 months ago) and tuned (couple weeks ago) professionally.
When I had it tuned a couple of weeks ago it was running perfect, 11.2-11.5 afr (aem wideband and keydiver chip) and 22psi on a 68hta. As of 2 days ago right after running about 15 psi at 70-80% throttle it started sputtering and running super rich all of a sudden. AFR's are 11.0-10.2 while driving normally (partial throttle, 20-0 psi of vacuum) and 10.8-10.0 (and beyond) under any kind of boost. The engine sputters in each case and I am unable to rev past 4000 rpm due to the rich condition. Initial idle (1500 to 1000 rpm) is around 15.0 afr then quickly starts running rich with an afr of 10.5 or less and eventually bogs and cuts off. Had a boost leak done and tps sensor adjusted right before the tune. I also noticed I was steadily running a bit richer than usual (afr's 11.2-10.5) at 80-100% throttle about 5 or 6 days ago prior to this happening.
Things I have checked:
- all spark plugs are getting a spark
- connected stock ecu, still had same problem (rich and rough idle)
- disconnected SAFC 2, still rich and rough idle
- checked vacuum lines
- tightened hoses and clamps and attempted to check for boost leaks by eye and sound
- disconnected MAF while engine was running and there was pretty much no change in engine characteristics (still super rich when idling and when rev'd up)
Does anyone have any ideas of what the issue is? I was leaning toward it being a MAF issue but I would think a broken MAF would be unlikely, anyone have a spare 2g MAF they want to let me use to test. I do not think it's a boost leak issue because with every boost leak I have had in the past the engine would idle fine and drive fine under partial throttle with lean to stoichiometric afr's then run rich under boost or higher throttle %'s.
When I had it tuned a couple of weeks ago it was running perfect, 11.2-11.5 afr (aem wideband and keydiver chip) and 22psi on a 68hta. As of 2 days ago right after running about 15 psi at 70-80% throttle it started sputtering and running super rich all of a sudden. AFR's are 11.0-10.2 while driving normally (partial throttle, 20-0 psi of vacuum) and 10.8-10.0 (and beyond) under any kind of boost. The engine sputters in each case and I am unable to rev past 4000 rpm due to the rich condition. Initial idle (1500 to 1000 rpm) is around 15.0 afr then quickly starts running rich with an afr of 10.5 or less and eventually bogs and cuts off. Had a boost leak done and tps sensor adjusted right before the tune. I also noticed I was steadily running a bit richer than usual (afr's 11.2-10.5) at 80-100% throttle about 5 or 6 days ago prior to this happening.
Things I have checked:
- all spark plugs are getting a spark
- connected stock ecu, still had same problem (rich and rough idle)
- disconnected SAFC 2, still rich and rough idle
- checked vacuum lines
- tightened hoses and clamps and attempted to check for boost leaks by eye and sound
- disconnected MAF while engine was running and there was pretty much no change in engine characteristics (still super rich when idling and when rev'd up)
Does anyone have any ideas of what the issue is? I was leaning toward it being a MAF issue but I would think a broken MAF would be unlikely, anyone have a spare 2g MAF they want to let me use to test. I do not think it's a boost leak issue because with every boost leak I have had in the past the engine would idle fine and drive fine under partial throttle with lean to stoichiometric afr's then run rich under boost or higher throttle %'s.
