Engine stops in heavy stop/start traffic
Discussion
It's showing OK now, and I'll say the engine is running OK now.
When they heat up, I guess due to cracks inside, something seems to move and the signal drops out. The ECU sees this as a stopped engine, and fuel and ignition stop too.
If your code reader can read the RPMs of the engine, try something like pulling the fuel pump fuse so you know it will just crank without starting, and have a check to see you can read a cranking speed, 300-500rpms.
Then, if it cuts out again, do the same thing and if you see no cranking RPMs, it's the crank sensor.
Tachos tend to have a dead spot at the start so cranking usually isn't enough to lift the needle from the stop, but at the same time, if you ever see the tacho needle kick about wildly, that is also a good sign that the crank sensor is playing up.
I can't say this is your problem, but it is something that turns up on BMWs a lot, and crank sensors usually are a similar design.
When they heat up, I guess due to cracks inside, something seems to move and the signal drops out. The ECU sees this as a stopped engine, and fuel and ignition stop too.
If your code reader can read the RPMs of the engine, try something like pulling the fuel pump fuse so you know it will just crank without starting, and have a check to see you can read a cranking speed, 300-500rpms.
Then, if it cuts out again, do the same thing and if you see no cranking RPMs, it's the crank sensor.
Tachos tend to have a dead spot at the start so cranking usually isn't enough to lift the needle from the stop, but at the same time, if you ever see the tacho needle kick about wildly, that is also a good sign that the crank sensor is playing up.
I can't say this is your problem, but it is something that turns up on BMWs a lot, and crank sensors usually are a similar design.
To get a plug lead off a plug with the Volvo 5 cylinder engine you need to take a boost pipe off, then remove the cover that goes between the cams - 8mm socket and a Torx T30 driver needed. It's not something I had the tools to do in traffic.
I have, however, ordered a new coil, which I'll swap in with the crank sensor.
I have, however, ordered a new coil, which I'll swap in with the crank sensor.
Changed the coil and the crank sensor today for new units.
Cleaned up the old crank sensor and dropped it in a cup of boiling water - resistance went from 294 ohms (room temp) to 360 ohms (90 degrees or so).
These sensors are meant to be ok if the reading is between 200-500 Ohms, so this one is theoretically ok.
However - the fault only occurs when the engine is HOT, how hot could this sensor expect to get?
Yes - I am still hoping that it's the cause of the issue.
Cleaned up the old crank sensor and dropped it in a cup of boiling water - resistance went from 294 ohms (room temp) to 360 ohms (90 degrees or so).
These sensors are meant to be ok if the reading is between 200-500 Ohms, so this one is theoretically ok.
However - the fault only occurs when the engine is HOT, how hot could this sensor expect to get?
Yes - I am still hoping that it's the cause of the issue.
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