New to me motor, no start, need help! - N54Tech.com

yak52 · **New to me motor, no start, need help! -** 10-01-2016, 04:32 PM

Hi guys,

New to BMW's. Bought an 07 335xi MT needing a motor. Car ran fine minus crazy smoke and lack of compression. Purchased a 52K mile motor from salvage 335xi w/ MT. Swapped motors, kept same MSD80 box, used harness from new motor, which was identical except for the ******** fix, which I transferred identically.

Swap physically completed, bled the cooling system, new fluids.....go to start and get 5 codes. Flip the switch on the ******** fix and the two O2 sensor codes go away. Other three codes are P1417, P0222, and P0123. All relating to the throttle position sensor, which is DEFINITELY plugged in. Found another thread for and E90 where the guy forgot to plug in sensor, got same three codes. Uplugged and re-plugged it probably 10 times. Also pulled the throttle pedal and checked the connection there. Looked fine. Car cranks, but does not start. Swapped the TPS sensor on intake to the one from the new motor...no difference.

Any ideas? I have INPA, however, didn't have computer nor the DCAN cable. Have never used it before though.

Does anyone have any experience with this kind of problem or can you point me in the right direction?

Thanks for any advice in advance.

Wheeliej · 10-02-2016, 02:21 PM

hey dude, new as well i think i need a new xi motor also knocking like crazy how much did you pay for your motor also did you know where i can get one I'm in NYC thanks

sorry can answer your question though

Texsquirrel · 10-03-2016, 11:05 AM

Check ground straps.
Also confirm you have fuel and ignition.
Fuel fire compression...which is missing?

yak52 · 10-04-2016, 08:02 AM

For anyone having this problem, the fix was to replace the entire harness, or check to make sure that you have the harness plugged in correctly. In my case, there is an issue with the actual harness because I swapped back to the original harness, hit the start button and she fired right up.

WheelieJ, to answer your question, I paid 2900 for a 335xi motor from a 6MT car with wiring harness (which turned out to be bad) and turbos, which I don't need, so I'll rebuild and keep as backups. Motor has 52K on it. The swap was a pain in the @55 though. I found it at car-part.com They delivered it to the dock at my work and I threw it in my pickup w/ a forklift to take home.