S60 T5 (MY2005) Intermittent rough idle & stalling ( replaced fuel sensor 0261230110 Topic is solved

[keng]

Need help. S60 T5 (MY2005) 201,000 km

I have intermittent rough idle problem for few seconds in last 3 weeks. It is about 1-2 times a week while stop at traffic light. There is no fault code in VIDA.

I cleaned the throttle body last week, however, the throttle body was pretty clean indeed since the last clean was about 3 years ago (160,000 km) There is no vacuum leak or air hose loose issue.

The above problem becomes more serious this week. I have 2 times of stalling problem. 1st time happened while driving and 2nd time while stop at traffic light. I was able to start engine after 2-3 attempts. After engine start back, the engine was kind of hesitating to accelerate and the RPM was unstable for few seconds.

Please help.

[oragex]

the fuel pump is solid on these cars, what goes bad is the FPS and the PEM - last one especially on models with metal gas tank

[abscate]

Once you rule out loose induction hoses ( you have to remove, inspect and replace to do this)

Pull plugs and inspect. If ignition coils are original, test by unplugging them while idling

Finally, the CVVT solenoid a have shown to fault without codes and give poor running. Recent thread

[mrbrian200]

You really need a VIDA-DICE or a good OBD tool for this one.

I'll also point out that the Bosch throttle body uses nylon gears inside, when they wear the throttle plate will sometimes stick in certain positions at roughly multiples of 7% (spacing of teeth on the internal gears). But not all the time. Sometimes the throttle plate will get stuck while trying to open. Sometimes it won't close to the idle stop (terrible idle because it's way lean). There's no way to repair/replace the gears as far as I know.

But without being able to look at live data/TPS position while the engine is running it's sort of a shot in the dark to say it could be this or something else. If this were the case though this is exactly how I would expect it to act. Nearly identical behavior to what my '06 was doing when I first bought it (same Bosch throttle body P/N on your '05 T5). However I was sometimes getting a CEL with DTCs for rich or lean O2, and codes indicating a MAF problem but interestingly never a DTC for the throttle body itself. It's a moderately expensive part, as is the PEM and other potential causes already mentioned.

You don't want to go blindly shelling out for these miscellaneous expensive parts without being pretty sure which one(s) are the cause.

[keng]

Plug, coil and fuel filter were considered new and only run for 25,000 miles, i changed it when I bought the car few years ago.

update: i cleaned MAF yesterday and problem still unsolved - rough idle for few seconds at traffic light today.

Good News!!! i got code!!!! VIDA show CEM290C fuel pressure. Signal too high.

VIDA:
Possible source
Damaged fuel pressure
Damaged fuel pump control module.

any idea how to fix it?

[abscate]

Confirm by measuring the fuel pressure at the rail.

There is a fuel pressure sensor on the rail which you can monitor the voltage to see if it's reporting correctly.

I'll try to find data on this

[abscate]

This is for my 2005 V70 but I guess they are the same

[precopster]

I just replaced a fuel pump on a plastic tanked 2005 XC70 with only 218,000 kilometres that had totally died.

Pig of a job.

[keng]

update: problem gone with replaced fuel pressure sensor bosch 0261230110

[hu5ker555]

Nice. That sensor is easy and cheap.