Cranks but no start. Topic is solved

[RickHaleParker]

Here is something that work for me on my S90. Disconnect the camshaft position sensor, see if the engine will start and run in derate mode.

[emtor]

How about the IAT sensor?

Oooops . . . thought you meant idle air control valve. so I went and pulled it off. It's soaking in carb cleaner at the moment.
I'll check the IAT sensor tomorrow.
Tried starting again today by depressing the throttle slightly and it fired up after cranking for some time. Runs very well, just as normal.
After warming up a few minutes I stopped the engine and restarted it twice. These two last times it fired up with no problems without depressing the throttle.
I'll check the IAT and the IAC thoroughly and see what comes out of that.

[emtor]

idle air control valve has been cleaned with carb cleaner and lubricated with WD40.
Boltet the IACV back on using the same gasket. Engine starts without cranking it to death but dies.
Engine runs with a little aid of the throttle pedal and runs with no throttle after being warmed up.
Fan keeps running for a while after engine is shut off, never done that before.
New fault code: P0102, MAF low input.
Replace MAF? -Hold your horses. P0102 may be a result of several conditions.

1)Dirty or contaminated mass air flow sensor
2)Failed MAF sensor
3)Intake air leaks
4)MAF sensor electrical harness or wiring problem

Idle air control valve may be leaking air through the old gasket.
I'll get hold of some gasket cement and see what happens before jumping to conclusions.
Then I'll pull the MAF. measure and clean it and take it from there.

I also tried disconnecting the MAF contact but no improvement.
New fault code: P0113, input air temp sensor. I think the IAT sensor is located within the MAF housing and that disconnecting it threw the P0113 code.

[emtor]

This is getting interesting.
Pulled the idle air control valve once more and made a gasket out of a double layer of doublesided tape.
Pulled the MAF which seems to contain the IAT-sensor as well and sprayed it with electrocleaner.
Engine started right up several times without the aid of the throttle and runs as it has always done.

A sidenote which points a finger towards the IACV: After mounting the IACV and the MAF I tried to start the engine.
Had to keep the throttle pressed down to make it run, so I wanted to see how far down I could get the RPM before the engine died.
I got it down to about 400 RPM. Idle is set to 800 in my car so the IACV was obviously not kicking in at all.
Turned out I had forgotten to insert the contact. Once in place the car starts and runs just fine.