Hi everyone,

I have a 1998 V70 AWD.

I have been out of town on business a couple of weeks and my wife said the car mostly worked great - which was a relief.

Then yesterday the car stalled while she had it out. There was no time to look in to it then. We had to go out briefly this morning and it stalled again while I was driving. It only happened once so I don't have much in the way of details, but basically it just shut off. The car was not totally cold and not fully warmed up.

I've been chasing a fuel mileage problem for months now, and have been slowly finding problems and solving them, so I'm surprised at this new stalling behaviour.

I've got a lot of confidence in the integrity of the intake/vacuum/evap system. I found a hole in an evap line, found my purge valve leaking, and found my compressor bypass valve diaphragm leaking. All fixed. I have been over the intake side of this engine a bunch in the last months and I'm pretty sure everything is working well.

I tested the MAF a few months ago using the method which back-probes the connector. I forget the specifics but I know the sensor tested perfectly.


Anyway I'm not clear on what the cause could be or what to check for, so I'm asking the board and I'll continue my own research while I await some advice.

These stalls are dangerous, and I'm reading a lot of reports of these cars (850s/S70s) stalling.

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1998 V70 AWD->FWD->AWD Turbo 225k+

A bad mass air sensor will cause stalling at lights and after a brief pause, a restart and resumption of normal driving until the next stall.

I have been considering the MAF as well, but as I said earlier the tests I've done on it seem to indicate that things are working well with this component... I will have to test some other things I guess.

I took it for a spin yesterday afternoon and gave it a bit of an italian tune-up once I felt like the oil had warmed up. It did not act like it was going to stall once all day after the initial incident.

I will probably get a fuel pressure guage and test that out next to make sure the FPR is working as it should. It's 15 years old and has 225k miles on it, and when I tried to test it with my hand vacuum pump (by applying vacuum to the vac line) I could build up a vacuum but it didn't hold very long - it seems plausible that something could be wrong there. I should probably have a fuel pressure gauge anyway.

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1998 V70 AWD->FWD->AWD Turbo 225k+

I gather that the car was subjected to mostly short/local trips while you were gone. If you still have a vacuum leak, however small, it could cause the plugs to foul while the ECT sensor is still reading cold. I assume there is no CEL.

You could check the wiring connectors, the fuel pump relay, but I would first check the spark plugs for dirt.

Klaus
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My name is Klaus and I am a V ♂ lv ♂ holic

thanks for the advice.

Yes mostly short trips.

No CEL.

Fuel pump relay is new (1 month).

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1998 V70 AWD->FWD->AWD Turbo 225k+