2001 S40 abnormal starting

S40VolVo01NC · Post by **S40VolVo01NC** » 20 Aug 2016, 11:30

Hello,
S40 Volvo 282,000+ miles. After the car has sat for a period of time 4 plus hours or over night it difficult to start.
The head was rebuilt 12,000 miles ago, Both O-2's and Cat, Fuel Pressure Regulator & filter replaced. Air filter, coil packs, plug wires & plugs as well as, all fuel injectors have been replaced.
Time belt, CamHub & VVT gasket, coolant sensor & thermostat replaced/Serviced within the last 200 - 3000 miles. Oil change just last week.
Fuel pressure test show fuel pump working correctly.
Once the car start it idle a little high/rough, then levels out. Performance is good, and restarts normal. CEL code states P0304, sometimes it will add P0301 or P0303 and I have visually checked each cylinder plug and wiring package and they appear good. Injector tested 8.5 - 8.6 Ohms. Fuel pressure 49psi when the key is turned to position 2, then 40psi when running. Pressure drops to 30psi after 35-45minutes.

Fuel 93 octane from Shell, Issues: After the car has sat for a period of time 4 plus hours or over night it difficult to start.

difflock54 · Post by **difflock54** » 20 Aug 2016, 23:40

Isn't the fuel pressure supposed to average steady about 44 psi.
The drop to 30 psi may be the issue?

S40VolVo01NC · Post by **S40VolVo01NC** » 31 Aug 2016, 11:38

the fuel pressure is holding above 20 overnight at the fuelrail now.
its like there is a gremlin in the car.
Drove it 255 miles yesterday, the CEL came on at 235 miles code P0304. minimal start issues and no run issues, the temp gauge started moving mid point to redline while the car sat still. Taking it in for a compression & link test tomorrow.