Ok. Car has been in shop for 5 days and we cannot find the issue. Here are symptoms:
- no codes excepts misfires in 1 or more pistons. its totally random and seems to affect the whole engine.
- it runs rich and eventually stalls when the problem happens
- we cannot make the problem happen often, but it never does it when engine is cold and only sometimes when engine is warm.
- I think we can rule our vacuum leak, intercooler, ETM or turbo hose, PCV system, PEM, coils and plugs (checked these)
I am left with a few options that are thermally (changes as the car heats up) related to the the fuel mixture- O2 sensor, MAF, Coolant Temp Sensor, Fuel Pressure Sensor (not thermally related to engine temp I think).
I need your brains for how to diagnose the what the issue is. How can I isolate these? Could it be something else? If I can't which one would you replace first?
Grateful for the help.
engine floods, stalls, randomly, s60R 2007
No thoughts?
Here is latest update of what we are trying: Clean MAF, replace ECT ($30), Replace FPS ($75), replace MAF, replace 02s. Sound like a good plan? missing anything?
Also this happens only when driving/under load, not while idling.
Here is latest update of what we are trying: Clean MAF, replace ECT ($30), Replace FPS ($75), replace MAF, replace 02s. Sound like a good plan? missing anything?
Also this happens only when driving/under load, not while idling.
John
-
JDS60R
- MVS Moderator
- Posts: 3532
- Joined: 21 February 2009
- Year and Model: 2007 S60R 2016 XC70
- Location: Mount Juliet, TN
- Been thanked: 3 times
I don't know anyones diagnostic skill level so I will try to explain basics ( not talking down to anyone -just trying to be clear)
You need data to move forward.(both at idle and under load) I prefer VIDA.
Look at codes freeze frame data.
Look at fuel trims both short and long
Oxy sensor reading and cycling
Boost pressure sensor readings at idle and under load
and put a vacuum boost gauge on to assure you haven't melted the cat.
A load sensitive issue is usually load sensitive ( sounds stupid but often overlooked) . The 07 R is going to use the pressure sensor (between the intercooler and throttle body ) along with other sensors to determine this.
An intermittent fault needs to have a component that "can" fail intermittently. This is usually in the electrical field after warm up but can be physical ( spark plug center ceramic breaks and falls down , egr (on cars that have them-yours does not) sometimes close fully and other times do not, fuel pressure regulators work correct for a while and then show odd signs or complete failure, fuel filters clog and unclog as the dirt moves on the media.
A rich condition is usually easier as it ruled out air leaks (95% of the time) already. You can run rich because the car thinks it should ( sensors - need the data for this) or because it can't lean itself out enough ( ECT reading wrong temp,fuel injector stuck open, Pressure sensor incorrect, MAF wrong, fuel regulator incorrect, return line blocked,cam sensor intermittent.
The data above will lead you to it. Start with those variables on the screen and get it to fail. Share what you found. Always start with cleaning the grounds. Diagnosing a car without proper voltage and good grounds is a waste of your time as your data will be incorrect.
I do not replace components that are within their normal service life without reason. If the oxy sensors or pressure sensor are more than 100K miles in use then replace them as maintenance.
It hurts me to hear of an R not at full operating potential. Driving a Volvo turbo ( especially an 07R) is one of the things that still makes me smile all day. I wish you were here. We would get it sorted today. ( and put on a downpipe and exhaust after we call Lucky)
You need data to move forward.(both at idle and under load) I prefer VIDA.
Look at codes freeze frame data.
Look at fuel trims both short and long
Oxy sensor reading and cycling
Boost pressure sensor readings at idle and under load
and put a vacuum boost gauge on to assure you haven't melted the cat.
A load sensitive issue is usually load sensitive ( sounds stupid but often overlooked) . The 07 R is going to use the pressure sensor (between the intercooler and throttle body ) along with other sensors to determine this.
An intermittent fault needs to have a component that "can" fail intermittently. This is usually in the electrical field after warm up but can be physical ( spark plug center ceramic breaks and falls down , egr (on cars that have them-yours does not) sometimes close fully and other times do not, fuel pressure regulators work correct for a while and then show odd signs or complete failure, fuel filters clog and unclog as the dirt moves on the media.
A rich condition is usually easier as it ruled out air leaks (95% of the time) already. You can run rich because the car thinks it should ( sensors - need the data for this) or because it can't lean itself out enough ( ECT reading wrong temp,fuel injector stuck open, Pressure sensor incorrect, MAF wrong, fuel regulator incorrect, return line blocked,cam sensor intermittent.
The data above will lead you to it. Start with those variables on the screen and get it to fail. Share what you found. Always start with cleaning the grounds. Diagnosing a car without proper voltage and good grounds is a waste of your time as your data will be incorrect.
I do not replace components that are within their normal service life without reason. If the oxy sensors or pressure sensor are more than 100K miles in use then replace them as maintenance.
It hurts me to hear of an R not at full operating potential. Driving a Volvo turbo ( especially an 07R) is one of the things that still makes me smile all day. I wish you were here. We would get it sorted today. ( and put on a downpipe and exhaust after we call Lucky)
Retired
Thanks JDS60R- I am at 100k miles. I don't think the O2 sensor going out could flood the engine plus it is not showing any codes. I have no access to a Vida accept 150 miles away at a dealer (unless there is someone in NW Arkansas that has one!). Today I replaced the FPS and still nada. So here is where I am at. I can't wait to smile again either.
Checked coils, plugs, cleaned MAF, replaced coolant Temp, and now FPS. Nada. Still starts running rich and dies after reaching operating temp. no codes. Should I reset the ECU by unplugging the battery for a few hours for the new FPS? any other thoughts welcome.
Oh, and my cat does not sleep in the engine compartment. I would have smelled that.
Checked coils, plugs, cleaned MAF, replaced coolant Temp, and now FPS. Nada. Still starts running rich and dies after reaching operating temp. no codes. Should I reset the ECU by unplugging the battery for a few hours for the new FPS? any other thoughts welcome.
Oh, and my cat does not sleep in the engine compartment. I would have smelled that.
John
Ok. Latest- in driving it and watching my scangauge2. The IGN numbers are jumping around like crazy. Fine at idle (about 12). I will accelerate a little, it goes up to 25 or 30. I let up on throttle. Then it drops to a negative number and engine starts stalling. It hovers at 1-4. I read the manual on the scangauge and it says "shows the amount of timing advance or retard." High is good, low is not. It says a low number might indicate wrong octane. My question: could I have some bad gas? Wouldn't that affect it all the time (not just when engine is warm). Anything else cause the IGN number to drop into negative numbers? Thx
John
-
- Similar Topics
- Replies
- Views
- Last post