Stalling when coming to a stop, need help

Post by **FireFox31** » 19 Dec 2023, 20:05

Hello, what could cause a 2000 V70 to start and run fine over 60 mph, run rough under 60 mph, then stall out when coming to a stop? I need a solution urgently yet can't access the car, so I'll have to guide the driver, my girlfriend, through the diagnostic and repair. What diagnostics could my girlfriend try to help identify the problem?

This is affecting Geronimo, a neglected 380k mile 2000 V70 NA automatic. My girlfriend drove it on her highway commute to work, but a few minutes in to her drive home, it stalled in an intersection. She got a jump start and drove it home on the highway. The car stalled out again when she came to a stop on the highway off ramp, then she got a tow home.

Sounds like a fuel delivery problem, but only at low speed. Could it be the fuel pump relay? Unfortunately, the Volvo 9434225 is backordered. FCP recommends a Stribel/Meyle 9434225 "multi purpose relay" with apparently filed off "Volvo" branding. Is that a good replacement?

Thanks for any help you can provide. The car is needed for work and I'm stranded far away for a long time, unable to help.

Post by **scot850** » 19 Dec 2023, 23:40

Fuel pump relay is a possible, but I'd expect it to be bad at all speeds not just lower speeds. I'm assuming there are no codes thrown?

MAF is a possibility, it could be failing or dirty.

A vacuum leak somewhere could be another possibility along with the fuel pump. But like the fuel pump relay not sure it is the issue.

VVT timing issue/failure?

Neil.

Post by **abscate** » 20 Dec 2023, 04:25

Not fuel delivery, I can send a fuel relay but that’s pretty sparse chance.

Vacuum leak is more likely, I think Geronimo is an NA? Throttle body is another candidate but usually the ETS light will warmly glow.

1999-2000 have to have a solid good 12.5 volt at rest battery or they will get snarly. The Silver Kat just reminded me of this with a start , stall, long crank, then a couple of spurious ETC codes , a fuel gauge which read inaccurately......all cured by a new battery

jmartin919 · Post by **jmartin919** » 20 Dec 2023, 05:45

So when it stalled out at the intersection she needed a jump start to get going again? Sounds like battery or alternator.

Post by **volvolugnut** » 20 Dec 2023, 07:09

jmartin919 wrote: ↑20 Dec 2023, 05:45 So when it stalled out at the intersection she needed a jump start to get going again? Sounds like battery or alternator.

Or high resistance wiring from battery to loads. Easy test for GF is a new, strong battery. Keep the old battery if you need a spare for other use.

Fuel and air problems not likely if runs well at higher fuel and air flows.

volvolugnut

Post by **FireFox31** » 20 Dec 2023, 11:53

Thanks for the input. On the first of each month, I check the battery voltage at rest before driving. It was ~12.25 V in Sept-Nov. It was 12.06 V in Dec four hours after having been driven so I thought the reading might have been off. The car starts fine but interior lights looked a little dim to me. I'll try to get a new/warrantied battery.

After the first stall, I don't think she tried to restart it, so the jump may have been unnecessary. On the second stall, I think she did restart it and it worked fine. It was towed due to the risk of stalling at the next stop. This is behavior I haven't experienced.

With a new battery, I'll have her drive around town to test before going too far afield.

jmartin919 · Post by **jmartin919** » 20 Dec 2023, 13:49

Not familiar with the V70 but I had a similar problem with my 93 850. It would just cut off when I came to a stop but start right back up and run fine. Turns out the problem was the accordion type plastic pipe running from the air box to the throttle had a crack in it and when stopping things would move just enough to cause it to open up enough to draw in unmetered air and cause the stall.

Post by **FireFox31** » 20 Dec 2023, 20:43

I had my girlfriend test the battery with a multimeter. It read only 9.86 V. I'll have her pick up the new battery tomorrow.

What could have killed the battery aside from age? My girlfriend recalled that the idle has had some slight fluctuation and running had some vibration for weeks. The alternator is a parts chain brand, but these symptoms don't match my experience with a non-charging alternator. Back in April 2022, the battery would die overnight, I never found a parasitic drain, and the dying stopped once the car was driven more.

My girlfriend was unable to pull the DTC codes because the OBD2 reader failed to connect. The ignition was in position 2, interior lights were on but a little dim. We'll try again with the new battery installed.

Thanks again for your input.

Post by **MoVolvos** » 20 Dec 2023, 20:58

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Clean the ETM in place. I have the 2000 S70 SE Base / NA. Just remove the piping and get a thin rag not thick or linty and first spray sparingly and directly on the butterfly and wipe down. Open the butterfly and mist more in and wipe the back of the butterfly besides the port. Careful not to strain the swivel points of the butterfly but do clean that area. During startup the engine will cough due to the residue and fumes but should smooth out. This fixed the low RPM roughness and stalling.

Also, while idling remove a coil wire and see if it runs worst or the same. Swap coils and test if you find removal did not make it run rougher.
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Post by **MoVolvos** » 20 Dec 2023, 21:02

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When it ran really rough at low mph the cause was two bad coils. Cleaning the ETM help the car not stall when started. Code for cylinder / plugs / coils but none for ETM.
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