Alex Crow
Senior Member
- Joined
- Jul 9, 2009
- Messages
- 10,677
- Reaction score
- 47
- Location
- Super Suffolk
- Your Mercedes
- W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
hfm uses an air mass meter to determine air flow into engine (the sensor on the intake pipe). pms uses manifold pressure and rpm mapping to calculate a value. your engine`s control unit needs this information to help calculate the correct injection period (how much fuel to inject at any given moment).
your regeneration valve is part of the fuel tank evaporative emission system, it allows fuel vapour vented from the tank to be safely and cleanly burnt off during the combustion process. the tank vent line has a pressure relief valve and charcoal cannister before the regeneration, or purge valve. disconnecting the down stream pipe and blocking off is not known to cause any problems for diagnostic purposes.
the correct test for the sensor involves use of diagnostic equipment and live data analysis, or swapping for a known good unit disconnecting and running without will not really tell you much........
so the reason i mention air leaks, particularly new ones where you have been :lol: is this will severely affect the ecu`s ability to correcly meter fuelling, with symptoms most pronounced at low rpm and throttle opening. perhaps check again the oil breather pipe or air temp sensor mounting?
your regeneration valve is part of the fuel tank evaporative emission system, it allows fuel vapour vented from the tank to be safely and cleanly burnt off during the combustion process. the tank vent line has a pressure relief valve and charcoal cannister before the regeneration, or purge valve. disconnecting the down stream pipe and blocking off is not known to cause any problems for diagnostic purposes.
the correct test for the sensor involves use of diagnostic equipment and live data analysis, or swapping for a known good unit disconnecting and running without will not really tell you much........
so the reason i mention air leaks, particularly new ones where you have been :lol: is this will severely affect the ecu`s ability to correcly meter fuelling, with symptoms most pronounced at low rpm and throttle opening. perhaps check again the oil breather pipe or air temp sensor mounting?