Thread: Cyl #3 NOT HAPPY =(

So I had my ecu retuned ( JWT ) this past spring and went to a bigger injector ( 72lbs ) I didn't buy MSD injectors but new Siemens MSD "style" injectors. The body was shorter and I had to double up on the injector bushing in between the injector and mani to make it fit. Well all summer long I had problems leaning out ( the plugs looked ok though and it felt fine) . It was creeping up into the 12's in the upper RPM's. I kept trying different things to correct it. Did the basics.. fuel filter, boost leak test ( to make sure it wasn't leaking form the injector bushing ) and tune up. I had installed a new Aeromotive FPR when I did the injectors. And a new Walbro 255. I couldn't figure out what was wrong and I ended up just cranking up the fuel pressure to compensate. I was at 3.5 bar instead of 3 bar. Then my wideband took a shit and I was thinking it was just my wideband the whole time. So I turned the fuel pressure back down to 3 bar cuz it was idling like crap at 3.5. So I went to an auto-x in august and after that I had a knock and blown up clutch. So I just got around to doing the bearings yesterday. #3 bearing was SMASHED! I mean SMASHED! 1,2 and 4 looked great. ( side note I had done new bearings about a year before ) So obviously # 3 injector or something is not working right. Should I just get real MSD's and throw them in? Just currious what you guys think. Any info is appreciated. On to the pics...

Good and bad bearings for comparison



GOOD!


BAD!

yeah, id imagine the crank is pretty beat up from that one. Definetly looks like oil starvation.

Even though the bearing looks terrible it didn't realy hurt the crank. Thank god...

If it was oil starvation wouldn't they all be chewed up?

Nope

#3 starves first and spins first.

ahh gotcha.. thanks for the info. I'm currious why #3 goes first. any explination?

Design of passageways to ensure that #4 doesn't starve prematurely.

On jwt programs you must run the correct injector or it will run lean. I have run into this before even when the injector flows the correct amount the lag time can be off causing it to run lean. As for the number 3 cylinder I have heard may different explanations. 1) All stock awd nissan manifolds have a issue that relates to the number 3 runner causing back pressure and extra heat. 2) when using the stock manifold the turbo is placed right in front of the #3 cylinder causing heat soak in that area. I know motoiq has a article that mentions the second issue. the first one was discovered by Andreas Miko.