Ive got a 2008 Transit Connect 210 1.8Tdci with 172k on the clock. A couple of years ago I blanked off the egr valve. Last weekend during the heavy rain the engine misfired and went to idle mode. Initially I suspected damp, but everything seems dry. Engine was going but no power and black smoke out the back. I let the van sit for 20 mins and it started and got me home.
Ive been reluctant to take the van out on the road since then and have been starting the engine on the drive and after about 8 - 12 mins the engine runs rough and lots of black smoke.
Ive traced the issue to the butterfly valve in the egr valve. Butterfly valve is normally wide open. When started engine runs fine and then after 8-10 mins, the vacuum pipe makes the butterfly valve close and starves the engine of air, causing lots of smoke and rough idle. If I disconnect the small vacuum hose that goes to the bellows mounted on the egr valve, the engine runs fine.
So after all that, any idea whats causing the butterfly valve to close starving the engine of air?
Any advice would be appreciated.
Thanks