Weird bucking issue in low rpms
Posted: Sat Apr 14, 2007 5:28 pm
I am in the process of tuning a motor with these specs
-k24 block
-cp 12.5:1 pistons
-k20r head
-some very large skunk2 cams(not sure what they are called, but i believe my friend is testing them for skunk2)
-rbc manifold
-410cc injectors
-rcrew header
-2.5" exhaust
...cant think of anything else at the moment
Anyways skunk2 sent him a map to use as a base. Even on their maps the car would buck like crazy if you give it any gas below 3k rpms with closed loop enabled even. I didn't like how some of the stuff looked in their maps so i started my own. Even after tuning out the fuel the car would buck like crazy at low rpms no matter what i did with fuel. I messed with fuel cut some too and it does make it run better on and off the throttle, but it still does the bucking.
Looking at the datalogs I see that when he steps on the gas in those rpms (below 3k) it will barely inject in any fuel and sometimes none at all for a second. The car just goes lean. Its acting like its something weird related to the fuel cut not kicking in right in those rpms, but i cant figure out what the deal is. Also his tps is set just fine. Any ideas? The car runs great after those rpms and idles great too.
-k24 block
-cp 12.5:1 pistons
-k20r head
-some very large skunk2 cams(not sure what they are called, but i believe my friend is testing them for skunk2)
-rbc manifold
-410cc injectors
-rcrew header
-2.5" exhaust
...cant think of anything else at the moment
Anyways skunk2 sent him a map to use as a base. Even on their maps the car would buck like crazy if you give it any gas below 3k rpms with closed loop enabled even. I didn't like how some of the stuff looked in their maps so i started my own. Even after tuning out the fuel the car would buck like crazy at low rpms no matter what i did with fuel. I messed with fuel cut some too and it does make it run better on and off the throttle, but it still does the bucking.
Looking at the datalogs I see that when he steps on the gas in those rpms (below 3k) it will barely inject in any fuel and sometimes none at all for a second. The car just goes lean. Its acting like its something weird related to the fuel cut not kicking in right in those rpms, but i cant figure out what the deal is. Also his tps is set just fine. Any ideas? The car runs great after those rpms and idles great too.