I disconnected the rubber hose off EGR valve and plugged it with a small screw. Unfortunately the problem continues. I know that the thermo valve between EGR valve and the throttle body opens at 50 degrees Celsius so that the vacuum can open EGR valve. That's the exact temperature at which hesitation starts and the engine bogs down until it reaches 80 degrees. I don't know of any other temperature sensor that opens at 50 degrees. If the problem was fuel related (fuel starvation) , I guess the engine would stall, right?

Could the problem be related to the catalytic converter?
Is this engine supposed to have warm up regulator (WUR)? I could not find it.

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Zorin

'88 Benz 420 SEL
'79 Porsche 911SC ('87 Carrera Engine)
'00 BMW 540 Sports Package
'99 Land Rover Discovery

86 300E - Manual (sold)
88 260E (sold)
84 944 (sold)