Arbelac Posted November 2, 2007 Report Share Posted November 2, 2007 On my 01 V70 T5:I pulled a code the other day, P1171 Long term fuel trim, bank 1... did some searching, looks like it could be the MAF. Car has a bit of a stumble at high RPM/WOT. Idles fine...Take MAF out, clean it good with MAF cleaner, reseat and clear code. Seems okay, but still has a stumble at high load sometimes.Sure enough, CEL came back on today, just pulled the code. P1171 is back, but there is also a P0234 Overboost code set as pending.Any ideas where to look now? The MAF appears to be changing correctly, I took it for a spin with the scantool hooked up and the MAF lb/min reading was changing (what appeared to be) appropriately.Apparently the O2 sensor could also be a culprit for the P1171 code as well...the scantool shows it changing between a range of values, anyone know what the range should be?Any ideas on what to look for in regards to the overboost code?As an aside, the car idles and runs fine below 2500RPM, the stutter is only noticeable above 3000RPM and not every time. I almost want to say it's turbo lag, except I'm not really familiar with what that would feel like... most of my cars have been N/A except for these two Volvos I've got now. Link to comment Share on other sites More sharing options...
smokin' T5M Posted November 2, 2007 Report Share Posted November 2, 2007 make sure the breather isn't clogged. will cause the Air Mass to act up. get a surgical glove and put it over the oil fill opening. This requires 2 people. 1 to hold the glove do it doesn't get sucked in or blow off and one to start the car. If after the car is started if the glove begins to inflate your breather is clogged. If it flutters or gets sucked down then all good there. Link to comment Share on other sites More sharing options...
Arbelac Posted November 2, 2007 Author Report Share Posted November 2, 2007 make sure the breather isn't clogged. will cause the Air Mass to act up. get a surgical glove and put it over the oil fill opening. This requires 2 people. 1 to hold the glove do it doesn't get sucked in or blow off and one to start the car. If after the car is started if the glove begins to inflate your breather is clogged. If it flutters or gets sucked down then all good there.Is the Breather box different than the PCV oil trap? Or is this yet another term... searches don't seem to clarify. Link to comment Share on other sites More sharing options...
Arbelac Posted November 3, 2007 Author Report Share Posted November 3, 2007 I've got vacuum at the oil cap. Just checked it.Wondering if it's actually the O2 sensor, as that's listed as a cause code for P1171. Wonder if the P0234 is spurious because the fuel was running lean and the ECU cut it, leading to too much boost for the fuel/air mix. The P0234 is also listed as pending, which means it hasn't happened enough to set the CEL on it's own...Anyone have a good vacuum line diagram for this engine? I can't see any cracked lines but some of them are hard to see where they go... Link to comment Share on other sites More sharing options...
Arbelac Posted November 3, 2007 Author Report Share Posted November 3, 2007 Further research shows that some people have resolved this by replacing the check valve/purge valve by the radiator...it's a cheap part, so I'll probably try that next...I'm open to any other suggestions... Link to comment Share on other sites More sharing options...
Arbelac Posted November 3, 2007 Author Report Share Posted November 3, 2007 Purge Valve replaced... still stutters/jerks when you pop the throttle. Link to comment Share on other sites More sharing options...
Arbelac Posted November 3, 2007 Author Report Share Posted November 3, 2007 I'm wondering if this might actually be a worn spot in the ETM, as it does it in any gear if you pop it past 3K RPM, it'll drop, then recover and continue accelerating... Link to comment Share on other sites More sharing options...
smokin' T5M Posted November 4, 2007 Report Share Posted November 4, 2007 On my 01 V70 T5:I pulled a code the other day, P1171 Long term fuel trim, bank 1... did some searching, looks like it could be the MAF. Car has a bit of a stumble at high RPM/WOT. Idles fine...Take MAF out, clean it good with MAF cleaner, reseat and clear code. Seems okay, but still has a stumble at high load sometimes.Sure enough, CEL came back on today, just pulled the code. P1171 is back, but there is also a P0234 Overboost code set as pending.Any ideas where to look now? The MAF appears to be changing correctly, I took it for a spin with the scantool hooked up and the MAF lb/min reading was changing (what appeared to be) appropriately.Apparently the O2 sensor could also be a culprit for the P1171 code as well...the scantool shows it changing between a range of values, anyone know what the range should be?Any ideas on what to look for in regards to the overboost code?As an aside, the car idles and runs fine below 2500RPM, the stutter is only noticeable above 3000RPM and not every time. I almost want to say it's turbo lag, except I'm not really familiar with what that would feel like... most of my cars have been N/A except for these two Volvos I've got now.The air mass should read between 13-15 Kg at idle with A/C off any higher and the air mass is bad or you have a vacuum leak. Injection time should be 2-2.3 ms any higher and that shows vacuum leak tooIs the Breather box different than the PCV oil trap? Or is this yet another term... searches don't seem to clarify.yeah it's the same. The purge valve is only for Evap syst emmisions has nothing to do with drivabilitly. Make sure you turbo vacuum lines haven't come loose near the turbo or at the Turbo Control Valve. They are color coded so make sure the lines are going to the correct port on the TCV Link to comment Share on other sites More sharing options...
Arbelac Posted November 4, 2007 Author Report Share Posted November 4, 2007 13-15 Kg/sec? or /min? Link to comment Share on other sites More sharing options...
Arbelac Posted November 5, 2007 Author Report Share Posted November 5, 2007 I'm getting 0.4lb/min from one scantool software, and 4 grams/second from my other scantool software... seems low?I checked the vac lines as much as I could...anyone have a routing diagram for this engine?Guess I'll bite the bullet and replace the MAF... Link to comment Share on other sites More sharing options...
Ihatespeedbumps Posted November 5, 2007 Report Share Posted November 5, 2007 On my 01 V70 T5:I pulled a code the other day, P1171 Long term fuel trim, bank 1... did some searching, looks like it could be the MAF. Car has a bit of a stumble at high RPM/WOT. Idles fine...Take MAF out, clean it good with MAF cleaner, reseat and clear code. Seems okay, but still has a stumble at high load sometimes.Sure enough, CEL came back on today, just pulled the code. P1171 is back, but there is also a P0234 Overboost code set as pending.Any ideas where to look now? The MAF appears to be changing correctly, I took it for a spin with the scantool hooked up and the MAF lb/min reading was changing (what appeared to be) appropriately.Apparently the O2 sensor could also be a culprit for the P1171 code as well...the scantool shows it changing between a range of values, anyone know what the range should be?Any ideas on what to look for in regards to the overboost code?As an aside, the car idles and runs fine below 2500RPM, the stutter is only noticeable above 3000RPM and not every time. I almost want to say it's turbo lag, except I'm not really familiar with what that would feel like... most of my cars have been N/A except for these two Volvos I've got now.I've seen overboost codes when the Turbo control solenoid acts up. It lets boost pressure get too high, then the ECM relizes it and retards timing and attempts to open the wastegate immediately. This may explain your jerkiness under high RPM and high load. Try a new TCV and let us know what happens. I've seen/replaced lots of faulty ones. Link to comment Share on other sites More sharing options...
Arbelac Posted November 5, 2007 Author Report Share Posted November 5, 2007 This might sound dumb, but where is the TCV and what does it look like?EDIT: Searching seems to reveal the TCV is also called a Boost Control Solenid? Judging from a pic from a 2000 S60, it looks like the valve that is sitting on top of my tranny in my 2001... Part number on mine is 9473212.Yes/no? Link to comment Share on other sites More sharing options...
Arbelac Posted November 5, 2007 Author Report Share Posted November 5, 2007 Just called the closest dealer and checked the AMM/MAF value...the spec is in Kg/HOUR... 13-15 Kg/h = ~4 grams/sec which is what I'm getting from my scantool, which means it's almost certainly the TCV then... Link to comment Share on other sites More sharing options...
smokin' T5M Posted November 5, 2007 Report Share Posted November 5, 2007 Sorry I forgot to add that important bit of info..... my bad!!! I would check the TCV it's located at the air box. It looks identical to the Evap Purge valve you have already replaced as well by the cooling fan. Link to comment Share on other sites More sharing options...
Arbelac Posted November 5, 2007 Author Report Share Posted November 5, 2007 TCV ordered it's going into tomorrow. Mine appears to sit on top of the tranny in an open space, with a little plastic hook holding in it the spot.Hope this fixes it! Link to comment Share on other sites More sharing options...
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