dolucasi

Keep us posted on the progress - Cheers!

190Efan

While I'm glad that your issues seem to be solved for now, you want to be wary of using aftermarket parts. They might initially be cheaper but they don't last as long which means you'll have to replace them more often. In the long run, that'll actually wind up costing you more money. In addition, after market parts weren't specifically designed for your car the way OEM parts are so they're not always compatible with your car. That lack of compatibility with your car may cause your car to have additional issues due to the parts incompatibility. Saving a few $$$ in the short term may not be so cost effective in the long term. Good job on the fuel cap diagnosis BetterDaze.

Isawelvis

Been doing some research on the Fuel Piump relay and what it sends signals too ( if that's the correct term)

Coolant air Temp'
Cold Start valve
kickdown (auto only)
fuel pump
RPM signal

I was able to buy a OEM one from the dealer. Still hoping this is what solves my problem.

190Efan

Given the age of your car, it's possible that it might be a bad fuel pump relay. Do you know if the fuel pump relay was ever previously changed? BTW, the MB Classic Center is your friend. They have a better supply of W201 parts than the MB dealerships have. They're also very knowledgeable about our W201 model. It wouldn't hurt to get in touch with them and see what advise they offer you. I know this from personal experience with my W201 over the years.