96 Volvo 850 turbo rough running/no CEL

[Thatbluegsx90]

Came out the other day and noticed a roughness in the running of my 96 850 Turbo, at idle it is more prominent in drive but is there in park/neutral, idle holds at 840-800, while driving it it noticeable on acceleration, it almost feels like a bad motor mount to a point. Also have been getting faint smells of fuel on shut down and every once in a while it takes instead of 2 cranks to start it takes like 5 and stumbles for a second but steadies right away... I've replaced Cap/rotor, Injectors with rebuilt bosch (had suspicion due to issues when i first bought the car), bougicord spark plug wires, swapped the coil with a known good one, i changed the plugs from the autolites that have been in the car for 3 years with new ones and changed the PCV (All was planned already and done AFTER this issue started) with no change. it isn't a typical misfire feel, more of a rough running. 43psi fuel pressure, 155psi compression across all cylinders. I'm leaning towards a dying Cam or Crank position sensor but looking for someone who may be more familiar with the specific vehicles

[scot850]

Somewhere on your car there is a fuel pressure valve. It may have failed so it is not holding pressure when you switch the engine off. The other favorite is the fuel pump relay failing. It may be on the fuel injector relay for your year of car.

The fact you get a smell of fuel, there could be a vacuum leak somewhere in the evap system allowing fuel vapor to leak out. Also check the top of the fuel pump and check the seal on the fuel pump and under the edge of the access port in the trunk for rotted or mouse chewed pipes.

Neil.

[matthew1]

Any codes? Sounds like a vacuum line or elbow.

FWIW my 850 T always had a faint smell of fuel... faint.