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2012 Mercedes SLK Falls on its face under heavy acceleration
Hey guys. I’m a bit stumped on a 2012 Mercedes SLK350 with M276 engine. Car came in, running exceedingly rich, barely could idle. On second start the next morning idled better. Took for a test drive, seemed to drive fine, but under wide open throttle around 4K RPM fuel rail pressure drops from 3000 PSI to 120 PSI instantly, then recovers. Because of the rich condition I have replaced the high pressure fuel pump and injectors, and now it idles fine without any misfiring. Cylinders 1 and 4 injectors were visibly leaking upon removal, but again, now that fault seems to be corrected. The car still falls on its face at WOT though. My logical next step (which was actually my original thought) is to consider the low pressure fuel delivery, but low pressure PSI barely even wavers 1-3 PSI when the high side dumps. I have verified with manual fuel gauge that scan data is accurate on low side. It stays within spec. So I thought I had verified that the low pressure side wasn’t the issue. Is there something else I should be considering? Just for fun I replaced the rail pressure sensor when I worked on the high side as well. Could a low side volume issue manifest in an immeasurable way? Thanks guys!
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