Results 1 to 2 of 2

Thread: BMW E36 M50B25TU Throttle and power issue

  1. #1
    Join Date
    Apr 2019
    Location
    Greece, Attica, Koropi
    Posts
    10
    My Cars
    '91 318i, '97 316i 2.5l

    BMW E36 M50B25TU Throttle and power issue

    Hello guys! This is my first post here, i finally decided to swap my M43B16 to a more powerful M50B25TU Engine.


    I bought the engine out of a 1991 BMW E34 518i (Originally the Engine was swapped from an 1994 E34 525i)


    It ran perfectly 6 months now on the E34 that a friend of mine had and about two weeks ago the transmission failed and the car was parked, so i took the chance to buy the engine.


    We sucessfully swapped it to my car last weekend and i noticed that the engine didn't perform as good as it did on the E34 which is a bit weird given the E36 is a lighter chassis.


    The first issue was a rough first start (It cranked for a while and it slowly raised the RPM and then stalled) after few tries we managed to make it idle, which sounded really good without any hicups or misfiring, when i tried to give a small amount of throttle the car would raise the RPM without a problem, but when i floored it, it sounded like it was bogging, it held around 2500rpm and you could hear the intake getting air but it would hessitate and it would not raise RPM as if it was in some kind of safe mode, if i let go the pedal slightly then it would go up.


    I took the car for a spin carefuly at first to make sure everything was bolted and connected properly and the first time i tried to floor it i realised the car didn't have much power.


    At that point i want to clarify that my chassis is a 1997 OBD2 if im not mistaken and the M50 engine is a 1994 OBD1, i read somewhere that you have to connect the VSS but im not quite
    sure.


    The only mod i did on the engine harness was to cut the Pin 7 of the DME Immobilizer.


    I changed the MAF, CPS, TPS, Spark plugs, DME, ICV.


    I removed the O2 sensor but i got the same issues


    With the car idling i gave direct 12V power to the Vanos Solenoid but as seen on a YouTube video the RPMs should go down because the Vanos locks the Camshaft, but mine went slightly up, also i hear some kind of rattle when letting go at around 4000rpm but compared to a failing vanos that i've heard its not that loud.


    I also checked today the ground wire of the engine and it was slightly loose, i tightened it but nothing changed.


    I really don't know whats wrong, i'm looking for a local shop that has a round connector scanner to see if i have any codes but meanwhile i thought to post here in case anyone could help me..<br>


    Thank you.
    Last edited by fanistop; 05-14-2021 at 08:12 PM.

  2. #2
    Join Date
    Apr 2019
    Location
    Greece, Attica, Koropi
    Posts
    10
    My Cars
    '91 318i, '97 316i 2.5l
    My car seems to run a little rich especially on low RPM, i came to the conclusion that due to bad oil in the engine the VANOS might be stuck open cause it rattles even on low RPM which is strange cause its supposed to be closed, the car over 4000rpm seems to be okay, not perfect, but it has some decent power, im still trying to figure whats wrong, i think im going to service the VANOS and work from there, if anyone had any similar issues and could give me his two cents it would be much appreciated.

    P.S.

    I also tried to connect my ECU to a diagnostic but it didn't communicate for some reason.

Similar Threads

  1. E36 M3 3.0L Power Issues
    By Szybki in forum 1994 - 1999 Euro M3 (E36)
    Replies: 9
    Last Post: 06-03-2013, 07:00 PM
  2. BMW E36 318I CONVERTIBLE Tail Light issue
    By cesarhmelendez in forum 1991 - 1999 (E36)
    Replies: 0
    Last Post: 02-23-2013, 12:11 PM
  3. BMW E36 Doors with working power windows
    By M3Alpine99 in forum BMW Cars For Sale / Wanted
    Replies: 3
    Last Post: 04-14-2006, 10:00 AM
  4. FS: BMW E36 Grey Sport Pakage Power Seats
    By infamous in forum BMW Parts For Sale
    Replies: 7
    Last Post: 12-29-2003, 01:14 AM
  5. FS: BMW E36 Grey Sport Pakage Power Seats
    By infamous in forum BMW Parts For Sale
    Replies: 2
    Last Post: 11-15-2003, 05:22 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •