Hey everyone! I recently bought an '89 325is with an M52 swap and had it shipped up here from Arizona. I had 2 friends down there spend a couple hours inspecting/driving it, and everything looked great. The swap was professionally done in 2010-2011 and it's had about 10k put on it since then.
Since I got it here 3 weeks ago though, it's had a couple major issues:
1. Runs very rich at idle, like it's stuck in open loop. I measured HC's at 1300 last week.
2. Pings under part throttle from about 3k to 4k RPM.
3. The temp gauge never gets above 1/4, even though laser temp readings of the radiator are at 180. (It does have a "low temp" thermostat for AZ weather, which I plan to replace with OEM soon.)
Current plan of action.
(Please let me know if there are steps I'm missing or could improve on here, as I'm a bit of a newbie with these motors)
1. Replace low-temp thermostat with OEM unit.
2. Check ECT sensors to see how they are wired up, since the motor was originally OBD2 but it's currently OBD1.
3. Run a continuity check to the ECT pinouts to verify proper resistance at the DME
4. Swap in a known-good 413 DME
Engine specs here in case that helps:
M52B28 from E39 528i
OBD1 conversion
413 (silver label) DME with TRM chip
540i MAF
VAC injectors (24 lbs/hr)
M50 intake manifold
Sport cams with 268 D .411 lift (Schrick maybe?)
M54 pistons (10.8:1 CR)
TIA for any help! If you're local and want to come by to help me troubleshoot, I'd greatly appreciate it.
Since I got it here 3 weeks ago though, it's had a couple major issues:
1. Runs very rich at idle, like it's stuck in open loop. I measured HC's at 1300 last week.
2. Pings under part throttle from about 3k to 4k RPM.
3. The temp gauge never gets above 1/4, even though laser temp readings of the radiator are at 180. (It does have a "low temp" thermostat for AZ weather, which I plan to replace with OEM soon.)
Current plan of action.
(Please let me know if there are steps I'm missing or could improve on here, as I'm a bit of a newbie with these motors)
1. Replace low-temp thermostat with OEM unit.
2. Check ECT sensors to see how they are wired up, since the motor was originally OBD2 but it's currently OBD1.
3. Run a continuity check to the ECT pinouts to verify proper resistance at the DME
4. Swap in a known-good 413 DME
Engine specs here in case that helps:
M52B28 from E39 528i
OBD1 conversion
413 (silver label) DME with TRM chip
540i MAF
VAC injectors (24 lbs/hr)
M50 intake manifold
Sport cams with 268 D .411 lift (Schrick maybe?)
M54 pistons (10.8:1 CR)
TIA for any help! If you're local and want to come by to help me troubleshoot, I'd greatly appreciate it.
Comment