02 S60 engine shudders, stops as if on empty tank + restarts

sergio · Post by **sergio** » 15 May 2015, 07:19

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This car runs smooth like a new one then suddenly, as if the tank was empty, the engine shudders, coughs, stops but restarts. It makes a much softer but similar noise to a pre WWII single engine aircraft! (without the spitting smoke)
It happens after 60-70 of highway, or just few minutes of city driving. Sporadic but very annoying.

Tank is full. Gas filter replaced a year or two ago. I cleaned the Bosch MAF sensor even though it was replaced a year ago. The PCV was cleaned couple of years ago.
Codes don't point to the problem.

Can anyone shed some light?
Thank you.

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Post by **oragex** » 15 May 2015, 13:51

That year had a recall on the FPS - fuel pressure sensor, already replaced?

bigbrain · Post by **bigbrain** » 15 May 2015, 13:52

When this happened to me it was the fuel filter....but I also assumed it was the MAF! Only thing I can think of is a blockage between the tank and the filter if the filter has been changed..maybe there is a way to back flush the pipe....I've never tried though. When my filter blocked I had run the tank right down to empty.

sergio · Post by **sergio** » 15 May 2015, 17:15

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Thanks both of you guys

The recall doesn't affect me, I have checked my VIN against Volvo's recall winning numbers, wasn't there.!!

Fuel filter, as I said was changed couple of years ago. The problem is recent.
I forgot to say that I at my last fill up, I added a double dose of STP for cleaning them 5 candles!

I am going on observation to see what event precedes the incident. Maybe that will indicate a reason.

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mrscullini · Post by **mrscullini** » 15 May 2015, 20:17

"codes don't point to the problem", are you showing any codes or pending codes?

i don't think a double shot of STP would cause the problem.

even though you are not on the vin list, sounds similar to a fps issue. do you have a code reader? good way to monitor live data.

bigbrain · Post by **bigbrain** » 16 May 2015, 07:40

Might have cleaned all the gunk in the tank? Personally given the cost and ease I would maybe swap out the filter again just to be sure. I think when my filter blocked the car maybe thought the drop in pressure was caused by a catastrophic fuel leak and the safety shutoff was kicking in. That might happen if you have a partial blockage...just enough to trigger the shutdown. Its not my area of expertise....that was just my guess based on what the car was doing....it seemed to be shutting down rather than dying due to fuel starvation.

sergio · Post by **sergio** » 24 May 2015, 18:53

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Too sporadic and unpredictable to associate the fault with a practical event/reason

I read
ECM-1600 Boost pressure sensor - Signal too low
ECM-170F Boost pressure sensor - Faulty signal
I disconnect, reconnect the sensor I get the same reading. Erasing all between each reading.

How do I know whether it is the sensor or the wire that should be replaced (or both)?
How do I test the wires? What voltage at which pin.
Would this be at [ 54/1B ] on the electrical schematic?

I have changed a few sensors to consider today that replacing any sensor, when it should not, a criminal act.

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Post by **abscate** » 25 May 2015, 04:41

A boost sensor error won't make your car stall. The ECU will limit or shut off boost and your car will drive like Grandmas Volvo.

I'm not sure your stalling is fuel related. A single intermittent coil will make these cars run very rough. Pull out each coil pack and give them a good inspection for oil, corrosion, carbon arcing. There is also a thread on measuring resistances in the P80 forum, too.

Post by **vtl** » 25 May 2015, 06:50

abscate wrote:A boost sensor error won't make your car stall. The ECU will limit or shut off boost and your car will drive like Grandmas Volvo.

Shut off even if it reads low?

So what if MAP reads lower than the pressure really is? Fuel mixture won't be stoichiometric, that would cause misfires. I'd swap it just because MAP is cheap

sergio · Post by **sergio** » 25 May 2015, 07:54

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@ abscate

Thanks, I actually had to replace one coil, couple of years ago (don't remember why, misfiring maybe?)
I will check them.

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@vtl
I replaced the MAP last year, (new BOSCH from Rockauto). I was getting a low reading, mind you I still do ;-( Maybe I should use the old one to see what happens.
This is one of my reasons to be reluctant to replace sensors just because of bad readings.
The most if not the ONLY important thing is the correct diagnostic which is made more difficult with on board computers.

(God knows how much I miss my brand new 1968 /900 lb /850cc Mini Moke) manual transmission, I shifted without touching the clutch, just by ears.

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