Volvo Repair: Diagnostic Codes, fuel pressure regulator, volvo engines

Question
My Volvo is a 1989 240(gas). The check engine light came on and the codes that I retrieved are 2-3-1 and 2-2-1. Both indicate rich/lean or extremly rich/lean running condition.
If the spark plugs and plug wires are good, what else should I consider as a possible problem for this condition. The system is an LH 2.4
Thanks,
Bill


Answer
Hello Bill,  First off, Volvo engines hate a vacuum leak.One area to check is the small vac hose,that comes from the firewall,it feeds vac to the flow buttons on console.Others are the two at the throttle body.Repair as needed.Also check the o2 sensor,use volt meter,set to d/c take red lead to the single wire conector of o2 (its on the pass.sd. by the wiper motor.)peel back the triangle shaped black cover.Keep it connected.Take black lead and ground it to the cylinder head. It should variate volts between 0.90 to 0.20 With HOT engine,with no more than 5/7 seconds between changes.If not it could be sending false sigs to the computer.Take off the hose to the fuel pressure regulator,if ANY fuel present,it failing Thank You and good hunting!  PKD