v8vette84

My LT1 that I had tuned by madtuner seems to have an issue where when the car is idling the car will almost stall out and the check engine light comes on. I decided to datalog it to see if I could see the problem and the DTC's. The codes were lean on banks 1+2, and when the car almost stalls out the car goes into Open loop from closed loop and the car is already warmed up.. Throughout the logging the car switched back and forth between open and closed loop numerous times. I'm not sure if this is right or not but I would figure it's not as the car almost stalls or does stall out when switching over. Let me know what you guys think. It's a little annoying when you are slowing down and the car stalls. Would this be a tuning issue or something wrong with the car? The check engine light only comes on when the car goes back into open loop and almost stalls....
Stock cube LT1, new bottom end, ported heads, LLoyd Elliot custom cam (232/240 one), 52mm TB, Long tubes, 3" all the way back, no cats. Car seems to run fine but has idling issues. Ran the car last year with the same bottom end with stock heads and cc503 and it ran great. Any ideas?

v8vette84

When I started the car for the first time the car surged quite a bit and would not idle all that well, almost stalled a lot. Then the next day I started her up and she idled alright. Also when I'm driving the car at ANY speed the car will not idle down, rpms stay at 2k... If I'm going 10 mph and push the clutch in the rpms will go right to 2k and stay there. Once I stop it takes about 15 seconds and the car will idle down. This is quite annoying so any help is appreciated!

v8vette84

Any ideas?

kobraa

iTrader: (1)

Same issue, no idea whats wrong. I am getting a new MAF and possibly a re tune.

F0x Slaughter

Did you get a retune after the cam swap?

The LE cam is a .573/.568 lift to the 503 is a .536/.544 lift.

v8vette84

I most definitely did. I even had the tuner recheck the tune I got. I figured out the problem. The tuner said my O2's were reading REALLY lean so the car would go back into open loop to richer the mixture up as open loop runs rich. So then I started looking for leaks in the intake system. I shot some carb cleaner around the base of the intake manifold and she revved up a little bit with every shot of carb cleaner. So I replaced the gasket and so far so good, stays in closed loop, doesn't stall, idles good, and the O2's read correctly.

v8vette84

So far so good, I guess we'll see what happens.