bimmerd00d
01-08-2007, 05:21 PM
1990 525i 5-spd. Black/Tan, Big pile of crap right now to be honest....but it has a straight body and new brakes/suspension. The motor has issues, any of you M20 guys have some insight? All I have experience with is the M50 and M62.
Initial problems i've found so far are this.
* Upon startup, it takes a LOT of cranking to get it going
* Once running, while code the idle bounces up and down
* When trying to drive it, it jerks its way through first and some of 2nd gear...like i'm tapping the gas pedal.
* When moving, all seems well, it just doens't have a whole hell of a lot of power.
First things i plan on checking:
* Air leaks (intake boot, vacuum, etc)
* AFM (unplug and see if it improves)
* Coolant Time Switch
* Throttle Position Sensor (no idea how to check this, searching)
* Idle Control Valve (could cause nasty idle, but doesn't explain rough start through 1st gear)
* See if the cap and rotor have any cracks or anything, and bad plug wires.
Initial problems i've found so far are this.
* Upon startup, it takes a LOT of cranking to get it going
* Once running, while code the idle bounces up and down
* When trying to drive it, it jerks its way through first and some of 2nd gear...like i'm tapping the gas pedal.
* When moving, all seems well, it just doens't have a whole hell of a lot of power.
First things i plan on checking:
* Air leaks (intake boot, vacuum, etc)
* AFM (unplug and see if it improves)
* Coolant Time Switch
* Throttle Position Sensor (no idea how to check this, searching)
* Idle Control Valve (could cause nasty idle, but doesn't explain rough start through 1st gear)
* See if the cap and rotor have any cracks or anything, and bad plug wires.