Guys, having a bit of a prob with the car at the moment. Its missing a bit at low revs, and is using more fuel than normal. I thought it could have been the coil, as it has caused problems in the past, so i replaced that, but it was no better. I should have realised that this wasn't the problem, as the tacho was still moving smoothly, not jerking about like it would if there was a coil problem.
Now, i think ive worked out that the problem is the oxygen sensor, or its connector. My reasoning is as follows:
The FI computer on the car (Bosch MonoJetronic) has a set of base maps, and it stores updated maps in static ram (not flash
). This means that if you disconnect the battery for a while, it forgets all it has learned, and goes back to the factory defaults. Obviously, when i hooked the new coil up, i had to disconnect the battery, and so when i got it all back to gether, the computer was setup on base maps, and while it took a little while for the idle to settle down, the car was pretty good (no misses, much more power).
However, as time goes by (couple of days) the misses are coming back, and its getting more and more like it used to be.
Now - if the oxygen sensor is reporting lean all the time (which i suspect it is) this would mean that the ecu goes "fark, inject more fuel", which in turn would cause missing at low revs (A/F much too rich) and fark with my fuel economy.
Can anyone see any flaws in this reasoning?
Cheers Ken
Now, i think ive worked out that the problem is the oxygen sensor, or its connector. My reasoning is as follows:
The FI computer on the car (Bosch MonoJetronic) has a set of base maps, and it stores updated maps in static ram (not flash
). This means that if you disconnect the battery for a while, it forgets all it has learned, and goes back to the factory defaults. Obviously, when i hooked the new coil up, i had to disconnect the battery, and so when i got it all back to gether, the computer was setup on base maps, and while it took a little while for the idle to settle down, the car was pretty good (no misses, much more power).However, as time goes by (couple of days) the misses are coming back, and its getting more and more like it used to be.
Now - if the oxygen sensor is reporting lean all the time (which i suspect it is) this would mean that the ecu goes "fark, inject more fuel", which in turn would cause missing at low revs (A/F much too rich) and fark with my fuel economy.
Can anyone see any flaws in this reasoning?
Cheers Ken
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