running rough at 3400 rpm
 

i had to change my alternator in my x5, when i hooked the battery back up and started the car it wouldn't hardly run,it has cleared up some but at around 3500 rpm it starts cutting out and my battery light is still on,,can someone help

probably some adaptation issue, give it a little while and the ecu should readapt.

thanx for your reply,,i hope that is the issue,,,thanx again

the car seems to running ok but when i try to use passing gear it still boggs down and the battery light is still on any ???????

Battery light indicates a problem with the charging system. Have you thrown a digital meter on the battery terminals while the vehicle is running? Should be 13 to 15 volts MAX. If its not you need to find out why. Where did you get the alt? was it new, reman, aftermarket, oem. Just because its "new" doesn't mean it works or has the specific internals for YOUR vehicle (aftermarket etc.). How do you know your battery is not past its half life and the internal impedance monitor in the vehicle doesn't know this? Need a little more info to really help you nail it down. The lag is most likely limp mode on the PCM letting you drive but not to the vehicles potential because your vehicle "thinks" it needs a repair even though you've already done one. The other thing, what did you have to take off to do the repair? Are all the vacuum lines back and in the right place? Is the boot btw the MAF and throttle body secure and not letting unmetered air through (I'm not 100% positive of your specific intake design). Basically what changed between the vehicle working and not working. Sometimes stuff getting unplugged and plugged back in will cause the pins indie the connectors to push apart letting the connectors click together but not completing the circuit, retrace your steps double check everything if you think of any other details I'll try to help. Good Luck

the alt. was a rebuilt for the x5,,had the bat. and the alt. checked, both were up to specs. i did not do the work so im not sure what was removed. he did say some of the vac hoses looked dry and brittle. i plan on changing those asap the car is just weak, not like a 4.4i should be. i just dont trust the car on long drives.....thanx so much for your help...