Rovergauge Long Term Trim +100% Poor MPG
Discussion
Ok fitted all new plugs last night and the car seemed ok on a little shakedown this morning. AFM is alive again no longer showing 0% direct but a new one is on order. I suspect it's become temperature sensitive but can't confirm yet because my crap work laptop crashes when running RoverGauge so I'm borrowing the girlfriend's laptop to log a full run as I know it doesn't crash when running RG.
Tidied up a few things in the engine bay this morning, cable tied one of the lambda wires away from the manifold as it was touching and I imagine getting very hot. Tried wiggling all the wiring in the back of the AFM whilst running and made no difference so I'm pretty sure the wiring is sound. Can't wait to get to the bottom of this issue finally so I can spend my weekends tarting up my rocker covers and plenum instead of fault finding.
Tidied up a few things in the engine bay this morning, cable tied one of the lambda wires away from the manifold as it was touching and I imagine getting very hot. Tried wiggling all the wiring in the back of the AFM whilst running and made no difference so I'm pretty sure the wiring is sound. Can't wait to get to the bottom of this issue finally so I can spend my weekends tarting up my rocker covers and plenum instead of fault finding.
Ive only ever ordered a stepper from Britparts and that was fine. As far as Im aware you simply cant get new Lucas ones now, but check the stampings on the unit, it should not be marked as Lucas if its a replica. The replica units are not as heat tolerant as the Lucas, that you might not notice on a Land Rover, but the TVR really cooks them so close to the manifold. Ill be interested to see how you get on.
You can make your own heat shield pretty cheaply but they are available to purchase.
http://www.actproducts.co.uk/product/sp005-rover-a...
http://www.actproducts.co.uk/product/sp005-rover-a...
I'll get hold of one of those heat shields too because the AFM seems to be working fine in the colder weather we've had this weekend. Still will log my drives in traffic this week as that's where she's misbehaved.
Logged a run out today and nothing untoward to report. Made the below graph of lambda short term trim percentage for both banks, seems to be fluctuating fine but over the whole 20 minute drive (short fuel stop about 1/4 in) it seems to average around +30%. Is that normal?
Logged a run out today and nothing untoward to report. Made the below graph of lambda short term trim percentage for both banks, seems to be fluctuating fine but over the whole 20 minute drive (short fuel stop about 1/4 in) it seems to average around +30%. Is that normal?
Thanks Blitz.
Ok so logged this evening's drive home still on the old MAF. Was fine on the way back fans only cut in 3 times. MAF worked fine throughout. Car did nearly stall itself again upon startup but sorted itself out after a few seconds- my stepper motor value starts at 100% then drops to c.77% for about a second and a half then rises back up to 99% to stop it stalling, then slowly creeps down as you'd expect. Is this normal, or is this what's causing my near stalls on startup? Water and fuel temp reading 26 and 27 degrees C at that point.
Got home fine, parked up and put the roof on, fuel temp reading at 36 degrees C, water temp at 93 degrees. Went to start the car back up to do a revving video for an uncle, still logging- MAF is dead, reading straight up 0% constantly even when fiddling with the connector. Car runs super rich map and then super lean every half second as it tries to keep the car idling smoothly, wreaks of fuel. Fuel temperature is now registering 47 degrees C where the car has been sitting for a few minutes and the heat soak has I reckon got to the MAF.
I'm going to see how things go with the new MAF but think the heat is cooking it, then compounded by a hot running engine when it does fail due to poor fuelling. It will, I'm sure be fine in the morning as it was yesterday and the day before. I think I'm going to try getting both the insulating jacket for it and the heat shield and see what happens.
Ok so logged this evening's drive home still on the old MAF. Was fine on the way back fans only cut in 3 times. MAF worked fine throughout. Car did nearly stall itself again upon startup but sorted itself out after a few seconds- my stepper motor value starts at 100% then drops to c.77% for about a second and a half then rises back up to 99% to stop it stalling, then slowly creeps down as you'd expect. Is this normal, or is this what's causing my near stalls on startup? Water and fuel temp reading 26 and 27 degrees C at that point.
Got home fine, parked up and put the roof on, fuel temp reading at 36 degrees C, water temp at 93 degrees. Went to start the car back up to do a revving video for an uncle, still logging- MAF is dead, reading straight up 0% constantly even when fiddling with the connector. Car runs super rich map and then super lean every half second as it tries to keep the car idling smoothly, wreaks of fuel. Fuel temperature is now registering 47 degrees C where the car has been sitting for a few minutes and the heat soak has I reckon got to the MAF.
I'm going to see how things go with the new MAF but think the heat is cooking it, then compounded by a hot running engine when it does fail due to poor fuelling. It will, I'm sure be fine in the morning as it was yesterday and the day before. I think I'm going to try getting both the insulating jacket for it and the heat shield and see what happens.
Managed to fit the new MAF in the car park at work and I can say its been working perfectly so far. I have also ordered a heat shield from ACT which is my first step in keeping the new MAF cool. If it gets cooked again then I'll go and get one of Zubak's MAF insualting jackets as well.
Haven't taken any readings on fuel economy yet but in terms of how it drives, the Britpart MAF is fine. Haven't yet tested it's thermal resistance in stationary 30 degree heat but got all of summer to do so. Also the issue with the nearly cutting out just after starting has cured itself after fitting a new MAF, not sure if related but good news.
Haven't taken any readings on fuel economy yet but in terms of how it drives, the Britpart MAF is fine. Haven't yet tested it's thermal resistance in stationary 30 degree heat but got all of summer to do so. Also the issue with the nearly cutting out just after starting has cured itself after fitting a new MAF, not sure if related but good news.
Final update on this issue. Since replacing the MAF with a Britpart one and fitting the ACT CF heatshield she's been perfect. MPG is 30-40% better now and the car is not showing any of the previous idling issues on cold start. As a precaution, once up to temperature I run the fans when below 20mph to minimise the chance of manifold to MAF heat soak. In the 30+ degree heat we've been having recently she's been a dream.
Time for a facelift
Time for a facelift
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