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Hi, I’m really hoping someone here can help me figure this out. My 2005 Land Rover LR3 with 126,000 miles started acting up a couple weeks ago. It began with just a poor idle. I’d describe it as an occasional rhythmic “BLURP”…??? Kind of like a mini backfire that you can’t hear but you can feel. That progressed after a couple of days to a full blown rough idle with loss of power and rough acceleration. Thats when I started getting the DTC’s. Cylinder 8 at first. Changed the coil from 8 to 6 and drove it a bit. That’s when I got codes for 3, 4, and “RANDOM MISFIRE” followed shortly there after by the dreaded “REDUCED ENGINE PERFORMANCE” message on my dash. BTW, cylinder 8 never threw a code again. So I changed the MAF, reset the driver adaptaion log and reflashed the TCM. That seemed to fix the issue until I let it sit for a few hours. When I started her up… Same thing. Rough idle, random misfire and REDUCED ENGINE PERFORMANCE. I let it be for a bit because I’m trying to avoid throwing parts a the car in the hopes of fixing it. So over the past week I noticed that if I drive the car long enough the symptoms go away completly and it runs perfect. So I started collecting live data via the torque app and I came to find that when the engine approaches 170 degrees the engine starts to smooth out. by full operating temp of 190 or so it runs and performs perfectly. this is leading me to suspect a sensor that gauges temperature. I’d really appreciate it if anyone has any input on the subject because from what I’ve read anything gauging temp usually results in bad performance when hot rather than cold.
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OK, I did some running around this morning and I took the opportunity to experiment with the FREEZE FRAME. This is what I was able to get. All I did was tap on “capture freeze frame” right after it threw a code.
Vehicle VIN: SALAG25435A348067
Vehicle Manufacturer: Rover
Vehicle Calibration ID: 6H23-14C204-FAAFreeze frame information:
——————
EGR Commanded = 0 %
EGR Error = 0 %
Fuel Level (From Engine ECU) = 60 %
Barometric pressure (from vehicle) = 14.504 psi
Voltage (Control Module) = 14.042 V
Engine Load(Absolute) = 33.725 %
Commanded Equivalence Ratio(lambda) = 0.996
Relative Throttle Position = 5.098 %
Ambient air temp = 57.2 °F
Absolute Throttle Position B = 33.333 %
Accelerator PedalPosition D = 14.902 %
Accelerator PedalPosition E = 14.51 %Here is one once she was warm.
Freeze frame information:
——————
Fuel Status = 0 byte
Engine Load = 49.02 %
Engine Coolant Temperature = 73.4 °F
Fuel Trim Bank 1 Short Term = 0 %
Fuel Trim Bank 1 Long Term = 6.25 %
Fuel Trim Bank 2 Short Term = 0 %
Fuel Trim Bank 2 Long Term = 4.688 %
Intake Manifold Pressure = 6.672 psi
Engine RPM = 1,086.75 rpm
Speed (OBD) = 0 mph
Timing Advance = 1 °
Intake Air Temperature = 64.4 °F
Mass Air Flow Rate = 16.03 g/s
Throttle Position(Manifold) = 16.863 %
Run time since engine start = 0 s
EGR Commanded = 0 %
EGR Error = 0 %
Fuel Level (From Engine ECU) = 60 %
Barometric pressure (from vehicle) = 14.504 psi
Voltage (Control Module) = 14.042 V
Engine Load(Absolute) = 33.725 %
Commanded Equivalence Ratio(lambda) = 0.996
Relative Throttle Position = 5.098 %
Ambient air temp = 57.2 °F
Absolute Throttle Position B = 33.333 %
Accelerator PedalPosition D = 14.902 %
Accelerator PedalPosition E = 14.51 %BTW… I’ll do the water test on Monday or Tuesday. My wife threatened me with bodily harm if I screw around with the car on Christmas weekend
‘Here is one once she was warm.
Freeze frame information:”engine Coolant Temperature = 73.4 °F?
parameters look normal when engine cold at 73.4 F‘All I did was tap on “capture freeze frame” right after it threw a code.”
Supposed to auto log a freeze frame when error code sets.
Looking for a hint that would cause misfire,
High positive fuel trims = vacuum leak, lack of fuel/sparkJust performed the water spray test as per ScannerDanner with no results. I also tried using another OBD2 APP and only found one freeze frame recorded and it’s the same as I posted which on this app is associated with a misfire on cylinder 4. Since I already have the codes, would it be advisable to clear them and read the next one that pops up which should result in freeze frame data?
Also, I’m still learning about fuel trim and O2 sensors. One thing I realized is that all or some of my O2 sensors are heated. Could it be that the heating function is not working? And if so, could that be causing my issues?
Good idea clear codes see what you get. Guessing the JLR SDD must have info on individual cylinder misfires?
The O2 sensor heater error normally sets right off.
The JLR SDD is a little different. Being symptom driven software it’s not straight forward as to how I access that information. I was meaning to sit down with it today and try to figure it out but I left it at home and now I’m stuck at the firehouse until tomorrow. Basically the way I’ve been using it is I click on a myriad of symptoms from drop down menus. Then it reads the stored codes and gives you probable options. The misfire codes resulted in a 66% probability of CAMSHAFT POSITION SENSOR BANK 1. I tested it as per the instructions that JLR SDD gave me and it checked out fine.
See if you can isolate an individual cylinder misfire. Would be in the live data portion of the scan tool.
If so then suspects are coil/plug/injector/ intake gasket/cylinder.An intake gasket can leak air or can leak coolant both could cause misfire at startup.
If no air leak then coolant leak may show up as one spark plug cleaner than the others.
You have removed inspected plugs?I haven’t due to the Chicago cold. But that was my plan since the weather is going to be in the 30’s tomorrow
If vehicle new to you, besides plugs, fuel injection could be a source of stumbling/misfire on startup.
Maybe a good throttle body/ fuel injection cleaning(cleaner run as fuel supply).
Lots of info out there on doing this.I’ve had her for almost 6 years. As is my routine I replaced the plugs when I got her as well as the battery (now on my second). I fully remove and clean the throttle body as well as replace the throttle body gasket every oil change. Knowing that this model has issues associated with the throttle body. Initially I had a stalling problem when I first bought it. So I removed all the injectors and built a pressurized fuel injector cleaner operated by a momentary switch and my compressor. I run 93 Shell ONLY and every couple months I throw a bottle of techron in the tank
Also the PCV was changed out about 4 years ago and I give that a spray with carb cleaner when I do the throttle body
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