Idle problems 90Q (NG engine)

[Eyvind Spangen]

Messed around a bit more today. I found that if I disconnect the DPR (dark 
grey on front of fuel distributor), the car will idle almost normal, just a 
bit high (just below 1000 rpm). If I reconnect it, it will stumble for a 
second or two, almost stop and then settle at about 500 rpm, way too low.

If I disconnect the oxygen sensor, it will usually stay at the almost normal 
idle, but sometimes, having it connected or disconnected makes no 
difference.

Conclusion: I'll replace the oxygen sensor and see how things act then.. :)