Most people dont worry about the plug behind the fuel pump , even bmw , after cheking plugs as advised ealier , then check fuel filter maybe blocking up & also for air leaks on tank side of pump .
New tyres should be fitted as pairs to the rear axle only , or 4 new one,s all round , avoid odd sise tyres . Why is the above important ? keeps VCU & IRD happy.
Hi , the only thing the Maf does on an L-Series diesel is control the ERG , it performs no other function !. Better off blocking erg anyway , plenty on site re this , Just do a search .
Hi , The haynes manual says that pump failure is usualy indicated by coolant leaking from the gland behind the pump bearing , says that if this symton is evident then the pump must be renewed . Good luck with it