I just bought a 2000 S40 1.9 Turbo. It was idling very rough and died when you turn on the AC. The car ran great at speed. I changed the Fuel Pressure Regulator and now it idles fine but when I touch the accelerator it starts to cough and sputter and will not rev up. Not sure what to do next.

 

 

+1. check the small S shaped tube on the bottom of the regulator

 

Thanks for the response! The Fuel Pressure Regulator came as a complete unit that included a new S shaped hose. Based on your recommendation I went back and made sure the metal line on the manifold wasn't clogged. Still no change.

So far I've changed the Coolant Temp. Sending Unit, the Mass Air Flow Sensor, Fuel Pressure Regulator and cleaned the Idle Control Valve and it still will not rev. beyond about 1200 RPM. It Idles really smooth at about 900 RPM but bogs down badly when I press the accelerator.

The Check Engine Light is on but the scanner I used showed no code. I've ordered one that says it will read vehicles from '99 and on.

 

Sounds like a vacuum leak. If you can get a scan tool that reads fuel trim, see what it says with the engine idling. If you have a large positive short term fuel trim like 15% or more, then you probably have a vacuum leak.

 

I put my scanner on it and came up with codes but when I tried to read them is said no codes stored in module. I checked for a vacuum leak but can't find one anywhere. Not sure what to try next, do you think I got a bad Fuel Pressure Regulator?

Thnaks,

 

Check the S shaped hose between the intercooler and the throttle body. It tends to crack and make strange driveability issues.

 

Hudini, Thank you. Yes, mine was completely gone, I got a new one from Volvo and replaced it right after changing the fuel pressure regulator.

Thanks again,

 

 

Wow...that could be it, I don't remember seeing it in the box. I'll dig into it.

Thanks,

 

Thanks to all who offered advise. I found the problem, I mistakenly thought the fuel pipe connecting to the FPR was supposed to come away from the rubber hose and crimpted it when I tried to get it off. Super bad mistake, now I have to replace the entire fuel line.

 

Ouch, as I recall that's not a cheap pipe. You might want to get one at the junkyard.