2007 V70 2.5t SSS (start studder stall)

zanzabar · Post by **zanzabar** » 15 Jan 2016, 14:40

http://forums.swedespeed.com/showthread.php?40300

My car has nearly identical symptoms as this thread, which appears to apply only to S40/V50 T5s. I start the car, it doesn't want to catch, will start if I hold the key at the ignition position long enough, but usually I end up letting it go by habit and it doesn't actually run. Always starts great on the next try and runs fine.

I am going to start exploring fuel pressure and pump activity, but do I also need to get to the dealer and have this software update done or what?

zanzabar · Post by **zanzabar** » 31 Jan 2016, 17:02

Haven't experienced this for a week or more, but just now got a P0600 and P0683 codes and "service transmission" warning. Don't have a very good feeling about this.

Any chance these are related?

zanzabar · Post by **zanzabar** » 01 Feb 2016, 13:54

Warnings and the P0600 and P0863 codes are probably a result of cheapo chinese ELM327 OBD2 connector and Torqe Pro monitoring app. So now I guess I need to monitor fuel pressure, etc, the old fashioned way.

Like I said I haven't seen the engine hesitate to start, or studder, or stall at all for maybe two weeks now. But occasionally the tachometer needle does bounce around up to 3k or so and then back down very quickly while starting. Does that indicate an issue with the engine speed sensor/crank position sensor?

zanzabar · Post by **zanzabar** » 03 Mar 2016, 16:18

Followup for posterity:
Cold starts are still vaguely slow, but have not seen the tach bouncing at all for the last month, and have not had it studder upon startup anymore either. The "repairs" that I suspect have cured this are a new MAF and three tanks of gas with full bottle of Lucas fuel system cleaner additive.

Post by **abscate** » 04 Mar 2016, 06:43

Thanks for the followup. My guess is the MAF was the culprit. Bad gas is really a pretty rare phenomenon unless the car has sat for years or something pathological

zanzabar · Post by **zanzabar** » 09 Mar 2016, 23:18

Agreed, I think it helped. I'm going to throw a set of cleaned/remanned injectors at it and see if there is any further improvement.

zanzabar · Post by **zanzabar** » 09 Sep 2016, 01:04

SSS is back. Tach jumps around occasionally, even sometimes during normal starts, but almost always during harder starts. Seems to happen especially in very warm weather after short trips? Drove it across the country this summer and didn't seem to be a problem at all. Got back home and SSS started happening again.

Might be octane related? Leaning towards trying to get the dealer to update ECM software and see if that helps like it did for all the V50 T5s in that SweedSpeed thread I linked up above.

zanzabar · Post by **zanzabar** » 21 Sep 2016, 10:39

This is definitely an octane related thing. I filled up twice with 89 instead of 91 and haven't had the SSS once.

Post by **abscate** » 22 Sep 2016, 07:59

Im not on board buying that it is an octane issue. Fuel is fuel. There is a fuel delivery problem of some kind. How about monitoring fuel pressure at the rail while experiencing the symptom?

zanzabar · Post by **zanzabar** » 22 Sep 2016, 11:10

Yeah, I think that would make sense. Can you recommend a good pressure tester gauge? I am tempted to get a Harbor Freight or cheapo Ebay unit but not sure if I trust the quality. Don't want to spend a lot of $.