1 Jetronic Airflow Sensor Question Wed Feb 19, 2020 2:15 pm
Point-Seven-five
Life time member
I have a 1989 K100RS SE that I'm putting back together to put on the road. Everything is ready to go, but I'm having problems with the fuel system.
The engine is very hard to start, and when it finally catches it only runs on two then three cylinders for a while until it can catch and run on all four. It is dumping fuel out of the header joint with the silencer. The spark plugs are very sooty black and damp when I pull them. Cleaning them will give me one, sometimes two starts before they need to be pulled again.
Obviously, it looks like the engine is running very rich. Fuel pressure is correct, and the water temperature sensor is good and giving accurate readings. Fuel is fresh, only a week old.
I am checking Bert's troubleshooting information and took resistance readings on the MAF. The readings at the Jetronic connector(with tank disconnected) are as follows:
Pins 8-5 363 ohms which is correct
Pins 8-9 200 ohms which is correct
Pins 7-5 120 ohms According to Bert's guide, approximately 80-85 ohms is correct
Pins 7-8 375 ohms According to the guide this should be about 334 ohms
Has anyone here experienced a similar problem with overly rich mixture and high resistance reading on the MAF wiper output? If so, is there a repair that can be done, or must the MAF be replaced. I have searched for an answer, but there doesn't seem to be anything documented beyond a thread that goes into doing an almost complete rebuild.
The engine is very hard to start, and when it finally catches it only runs on two then three cylinders for a while until it can catch and run on all four. It is dumping fuel out of the header joint with the silencer. The spark plugs are very sooty black and damp when I pull them. Cleaning them will give me one, sometimes two starts before they need to be pulled again.
Obviously, it looks like the engine is running very rich. Fuel pressure is correct, and the water temperature sensor is good and giving accurate readings. Fuel is fresh, only a week old.
I am checking Bert's troubleshooting information and took resistance readings on the MAF. The readings at the Jetronic connector(with tank disconnected) are as follows:
Pins 8-5 363 ohms which is correct
Pins 8-9 200 ohms which is correct
Pins 7-5 120 ohms According to Bert's guide, approximately 80-85 ohms is correct
Pins 7-8 375 ohms According to the guide this should be about 334 ohms
Has anyone here experienced a similar problem with overly rich mixture and high resistance reading on the MAF wiper output? If so, is there a repair that can be done, or must the MAF be replaced. I have searched for an answer, but there doesn't seem to be anything documented beyond a thread that goes into doing an almost complete rebuild.
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Present: 1991 K100RS "Moby Brick Too"
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175