Looking for help trouble shooting the EVAP emissions controls on my 1998 4.0 litre supercharged V8. This is a UK spec car with the single canister system. The issue is a smell of raw fuel under the car and drawn into the cabin with windows/roof open.
I replaced the purge valve LNC1515AA (form a salvage dealer) and the Rochester valve a little while ago but no improvement. I am now trying to get to the bottom of this once and for all.
I have just visually checked the hoses and lines and all appear correct. With engine off there is no flow through the charcoal canister; at idle there is flow, so I assume the Rochester valve is OK. This makes me suspect the purge valve. The wiring connections are purple and white. I get fluctuating voltage readings by back probing both with the engine running but don’t know the correct voltage values so am only guessing the readings mean that the signal to the PV is OK. There are no codes stored which again suggests to me that the electrics are within tolerance.
I took one of these apart recently to try and figure out how it works (see pics). As I figure it out, inlet vacuum acting on the diaphragm is insufficient in itself to open the purge lines but the added pull from the electromagnet is sufficient.
Any tips on trouble shooting/repair would be much appreciated.