Posted by Andy Broomhead on May 17, 2013, 12:59 am
Year of Manufacture *: 2005 Engine Size and Code *: 1.6 ( Optional ) ECU Type: mems 3 ( Optional ) Scanner Used: Dec ( Optional) Fault Codes: Modis
Hi. I looked at this for a garage, it came in with a reported misfire, they previously fitted a new front O2 sensor. Vehicle reported random misfire and fuel trim limits exceeded. Engine was running in open loop. Ltf was about -3.5% I stored and cleared the codes and watched the o2 sensors and noticed every 4 secs or so there was a 65v peak seen on the front sensor trace? I checked in EOBD but couldnt see it? I hooked up a modis and found the same result. I checked an earlier 25 and found it working correctly. I swapped over the coils and the front O2 sensor but with no change, I havnt proved this is why is is throwing the system into open loop and /or causing the misfire, but it seems like a probable clue, so I went away to think about it. Have done so but havnt come up with any ideas yet. Anybody seen this before? Thanks.
Re: Rover 25
Posted by Pete Mutlow on May 17, 2013, 8:27 pm, in reply to "Rover 25" Peter Mutlow
Hi Andy,
What were the fault codes? I am assuming PO300 was one of them. 65v peak...typo? Do you have any gas analyser readings? What is the driveability like and can you notice a misfire at all?
Regards
Pete M
Re: Rover 25
Posted by Andy Broomhead on May 17, 2013, 10:24 pm, in reply to "Re: Rover 25" Andy Broomhead
No typo 65v! And to add to the confusion, I checked a 56 plate 25 today and found the same result! So as to the misfire, the 65v is just a red herring, although an interesting one eh?
Fixed #
Posted by Andy Broomhead on May 20, 2013, 9:31 pm, in reply to "Re: Rover 25" Edited by board administrator May 23, 2013, 12:17 pm
Ok This is done and dusted. 65V o2 trace was indeed a red herring. Compressions all equal at about 25 percent less than others I have tested. It transpires they had a 2nd hand engine fitted last month....and declined the extra cost of having a new cam belt done whilst it was on the bench!! I just wonder if they will just fit another 2nd hand engine or do the belts?
on May 17, 2013, 8:27 pm, in reply to "