Question about a car being rich or lean?
Question about a car being rich or lean? In most cases after a cam is installed in a car with the factory tune will the car be rich or will it be lean. I'm still trying to figure out why may car felt faster before the tune. Maybe the car was very lean with the factory tune and I didn't know it. It's a mailorder tune but the car did dyno at 365hp and 351tq. I still think the torque is on the low side. Next time I will listen when you guy say dont get a mailorder tune. It also feels faster for the first few minutes of driving then it does when it warms up. Maybe he has the car tuned to cut some timing when fully warmed up or something by mistake. I wish I would of got a dyno tune in the first place so the tuner could know exactly what the car is doing.
The AFR started at about 13.2 and steady went up to about 14.0 at 5500 RPM and steady dropped to about 13.4 at 6300 RPM at max power. I sent the computer back and he added more fuel to richen the tune up. I haven't been to the dyno since he has added the fuel. The car still felt faster with the stock tune. He told me my timing maxed out at 28 degrees. Like once every other month I get the knock codes I'm thinking maybe this cam likes the stock timing better. I also don't know if the knock is false or real I just delete the code and it doesn't come back for 2 months.
OK, that info is a good start. Two common reasons why your AFR is off 1) Airflow 2) fuel if you haven't changed your injectors lately, then it's most likely related to airflow. Sounds like you are flowing more air than the PCM thinks (which makes sense considering cam and LTs) and therefore it's running leaner at WOT. Which brings me to my second point, if the WOT fueling is off there's a good chance the part-throttle is off too.
Try this and see if it helps any. Unplug your MAF, yes you'll get a few codes but other than that you should run fine. Drive it around for a while (to reset the fuel trims) and see how she feels. If it's allot better then you MAF cal is probably off. This isn't a permanent fix, but should give you an idea of which direction to look.
Try this and see if it helps any. Unplug your MAF, yes you'll get a few codes but other than that you should run fine. Drive it around for a while (to reset the fuel trims) and see how she feels. If it's allot better then you MAF cal is probably off. This isn't a permanent fix, but should give you an idea of which direction to look.
