As per title on a 1997 V70R. I thought it was located just forward of the fuel filter, but seemingly not..
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As per title on a 1997 V70R. I thought it was located just forward of the fuel filter, but seemingly not..
should be on the fuel rail for that year afaik, the same as the 850's
The FPR was relocated down the back of the engine (on the late 850s onwards apparently).
If you follow the fuel lines from the fuel rail down the back of the engine it should be just visible (on top of the engine subframe by the steering rack).
Thanks Gents - Im going to change mine as a matter of course! I have a lingering 0172 code that won't go away (all the usual stuff has been done, now I have to concentrate on the unusual....)
Then again thinking on about this issue, from my experience on my remapped car it, isn't unusual to see this code as it does relate to long term fuel trim, I get this when cruising on the motorway on long journeys to the drag strip, only seems to occur when high speeds are constant for long distances, regular variations in load and speeds seem to avoid this, I've come to believe that it's more down to a mapping error in the code, than an actual issue with the cars running and I do monitor my afr's with a good wide band gauge.
Strongly agree and I have long considered some error as you say, or the software simply going bad somehow.
I also agree about the load variation thing - It seems to be much better when using a wide rev band, then all of a sudden after a stable period of driving (or idling) it will throw it.
All that said, the car does have a very slight exhaust leak on the turbo flange to downpipe. This was a result of me fitting a 3" downpipe and not being able to get it fully sealed. I never thought this was a reason for the code though as it kept throwing it with the Standard exhaust as well.
I'm assuming when it occurs on your 99 ME7 R the ECU restricts the boost by a few psi?? It certainly does on mine (pre Me7) and the only way to restore full boost is to disconnect the battery for 10 minutes or so. Just cancelling the code with a basic reader doesn't cut it.
How do I read AFR's and what is it/are they?? I have one of those Bluetooth OBD readers that link to a smartphone - but it seems the old Motronic ECU is a bit old for it??!!
The bluetooth reader should work but being an older car the refresh rate is very slow.
And being an older car the O2 sensor is only a narrowband which means you won't be able to read AFR. You have to fit a wideband O2 sensor and separate controller/display to read the full AFR.
As you are the later 4.4 this should help you??
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I get the code on my 855 T-5r (motronic 4.3), but does not seem to effect the performance much if any, but does chuck up the MIL/Lambda light. I just normally cleared the code if the code came up before I was racing or just allowed it to put the light out itself by returning to varied driving over about 50 miles ( i.e. back to normal traffic, not motorway constant speeds). The code normally clears itself then. Hoping to be running data-logging shortly and will then be able to see exactly when this occurs. Lambda sensors could possibly cause this when they start to fail as long term trims are measured as smaller differences over a longer time period before flagged the error, than short term trims which appear to allow larger differences but measured over a shorter time period, before getting flagged, as I understand it and thus why I'm not too fussed by the code on my car, when it occurs from time to time. You may find you still have a very small vac/boost leak, not noticeable under driving to you, but long term your ecu and sensors could be realising that somethings not quite right. It could only need a pin hole in a vac pipe or elbow.
As for OBD readers I go with what Dave says and they are very limited on the data you can get (if the one you have will connect at all, which is normally my problem with obd connection). The installation of wideband air/fuel ratio (afr) gauge with it's own dedicated wideband lambda sensor is a very good move on our cars to really be able to see how fueling is behaving. I am currently using AEM's excellent wideband afr gauge which has the added bonus of being dual display and show boost and afr, in what configuration you set at the same time, the fail-safe version has the added bonus of being able to data-log afr/boost and rpm as well, but will set you back a good few pounds though.
Nice find Keith, I'd be very suspicious of the vac pipe to the fuel pressure regulator and the little rubber elbow into the inlet manifold on left hand end, hidden behind the power steering pump, both are easy to miss when tracing boost/vac leaks and are most probably badly perished by now, if still the original items.
Well, thank you for all the responses! I've just driven around 40 miles and it's thrown the p0172 again (as usual) and this time a p0131 (signal low pre cat 02 sensor). Both lambdas were replaced last year though.......
When I replaced the turbo hoses and NRV's last week (separate thread) I checked the infamaous elbow by the PS pump too. It's good and was replaced as part of a PCV change 30k miles ago in 2012. Spraying carb cleaner around it on idle yielded no increase in rpm. The vac hose to FPR is what I wanted to check, as it's no doubt original. If pulled off the NRV and it leaks fuel the regulator is toast apparently. Rare though so it seems, but worth a shot..
ETA: Just ordered a front 02 sensor and will fit tomorrow. Maybe the new one I fitted last November was faulty..