Engine surge 50 RPMs at 1200 to 1800
2006 E350 with 250,000 miles. Trans went in to limp mode, needed new valve body, car sat for a year before I had this done. Once fixed there was an issue with the Gas fill vent but it seems to have gone away after one tank. Immediately noticed a strange engine surge, very slight at about 1200 - 1800 rpms, not dependent on what gear, but only under load, goes away if going down hill. The surge is less than 50 rpms, can see it in the tach and feel it in the car. If you accelerate aggressively it will stumble then catch and be fine. This seems to happen cold or hot. Also recently getting the hard 1-2 shift.
I was getting "too rich" codes on 1&2, I replaced all 4 O2 Sensors, the MAF and I just did the swirl door linkage. Codes cleared after this repair
Tank and associated fuel system replaced within last 3 weeks by MB, Warranty. I have done the adaptive transmission reset as well.
All these repairs have been over several months, and there has been no change. Anyone have an idea what I can try next?
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