Murph4 1 Report post Posted August 8, 2023 Hey guys, I've recently upgraded my E36 328i to a newer E91 335i but I'm having issues with it i was just driving around and all of sudden lost cylinders 45&6 I've checked the coils they are all fine, replaced all spark plugs and changed bank #2 O2 Sensor but no change its still only firing on 12&3 cylinders. any help on what this might be or is it a common issue? much appreciated. Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted August 8, 2023 its also only done 135000ks Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted August 9, 2023 also i should mention apparently its got a stage 1 MHD tune done by the previous owner. Quote Share this post Link to post Share on other sites
elias 253 Report post Posted August 9, 2023 would need to read codes, but could be DME mosfets if its MSD80. Fairly common issue. Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted August 9, 2023 yeah the more i look into it the more it looks like thats the issue, whats the best way to fix it? just replace it or... Quote Share this post Link to post Share on other sites
elias 253 Report post Posted August 9, 2023 can get the mosfets replaced which is significantly cheaper than replacing the entire DME. 1 Quote Share this post Link to post Share on other sites
Driftit 2079 Report post Posted August 9, 2023 @promo will be able to help with the repairs. Based in wellington. 2 Quote Share this post Link to post Share on other sites
promo 93 Report post Posted August 9, 2023 Ah the old MSD80. once its got a tune on it the MOSFETS run at a higher voltage. Courier the ECU to me and I'll replace all MOSFETS with higher voltage ones so it doesnt happen in the future. 1 1 Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted August 9, 2023 thanks for the reply promo, How much would i be looking at the get the MOSFETS replaced with higher voltage ones? Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted August 17, 2023 hey guys ive just had confirmation that its not the injectors and that it is the MOSFETS in the ecu 1 Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted August 21, 2023 On 8/10/2023 at 7:44 AM, promo said: Ah the old MSD80. once its got a tune on it the MOSFETS run at a higher voltage. Courier the ECU to me and I'll replace all MOSFETS with higher voltage ones so it doesnt happen in the future. do you know how much higher the voltage needs to be on the mosfets so this doesn't happen again? Quote Share this post Link to post Share on other sites
Murph4 1 Report post Posted October 16, 2023 Hey guys, looks like the issues I was having was caused by the MOSFETS so I had them replaced with higher voltage ones thanks again for the advice, however when it was getting it diagnosed the garage I took it to swapped around injector #6 with #1 to rule out the injectors (which it did) however when they refitted the injector brackets they fitted the one that holds injectors 1-2 and 5-6 upside down so they weren't secure. as a result it has caused #5 injector to bounce around snapping the bracket holding injectors 5-6 and also snapped the metal fuel feed tube to #5 injector. I've managed to get another fuel feed tube however I'm struggling to find a injector bracket. would anyone on here have one I could buy? Cheers in advance Mark 1 Quote Share this post Link to post Share on other sites
Ooonst 4 Report post Posted January 19 On 8/10/2023 at 7:44 AM, promo said: Ah the old MSD80. once its got a tune on it the MOSFETS run at a higher voltage. Courier the ECU to me and I'll replace all MOSFETS with higher voltage ones so it doesnt happen in the future. Learn something new every day! Quote Share this post Link to post Share on other sites
