Any smoke? Same happened to my old MB3 and saw a light smoke coming from the exhaust, barely noticeable but told me it's been running lean so I changed the fuel filter and fuel pump as my electrics and relays were fine. I think in a previous life it was turned over on an empty tank and damaged the pump. I first looked to see if the pump was getting the correct consistent power and there were no shorts occurring.
After changing the filter, still occurred, changed the pump and all started to run fine.
