Technical Panda bonfire?

[koalar]

Sorry to bang on about the fuel supply but this is what my bike would do. It's fully electronic inlet port injection system very similar to a car and needs a decent pressure at the injectors.

Thinking out of the box - I presume the revs are rising in time with road speed. Clutch can also cause these symptoms but usually you'll hear the revs rise though speed doesn't increase.

I would never discount anything. So many thing give the same faults.


I would expect hesitation as the revs rise with a slightly faulty fuel pump. With the lambda sensors showing the fuel leaning out.


Both sensors are bouncing all over the place.


If they are bouncing all over the place from cold. It will not be due to fuelling being altered via the lambda as they are ignored initially.

Can still be a lot of different thing and you can go through the route of changing parts till the right part is found. Maybe early on or not depending how lucky you are.


The reason for asking for asking for a photo of the plugs was to see if all are the same as well as there colour.

Ambient temperature sensor also go faulty and bounce all over the place. Should be able to eliminate this quite easy at no cost just by logging its value. Should start at very close the outside temperature and rise slowly.

 

[scott gilmour95]

 

[scott gilmour95]

All have the light coloured hot look about them that the lambas had ambient on the wing wirror reads all right. Intake air temp has always been higher than ambient but have crossed it with other panda owners and doesnt stand out as it will always be drawing in hot air from within the engine bay

 

[DaveMcT]

The hunting I had (not really a problem) was at constant motorway speed almost like the brakes were dragging for a few seconds. It's virtually stopped with the new fuel pump - it's just about detectable. I suspect it was the pressure controller dumping excess fuel back to the petrol tank. I suspect the old pump would take longer to recover the pressure so the effect was more clear.

I didn't have a fuel pressure tester (and the OBD examiner system for BMW bikes is expensive) so swapping the high mileage pump made sense.

 

[koalar]

View attachment 174406

Again useful. Was expecting on to be different. And occasional fuel going down the exhaust causing the strange lambda readings.


Do look like lean rather than rich which is a start.

Try spaying some alcohol or lighter fuel under the air filter left hand side around the throttle body do the revs alter

 

[scott gilmour95]

Tried this before and no and when swapping the inlet manifolds over all gaskets were very flexible and no brittle or cracked rings (rubber ovals they were) this has happened with 2 airboxes and 2 different style induction kits

 

[koalar]

Sorry about the late reply have not been recieving notifications :/ and lambdas are all over the place has had new sensors cat and gasket to eliminate exhaust side. Temp gauage was reading wierd my scanner reads in 1 sec intervals and would go from 81 to 90+ and drop about 10° in a single second! So has been changed and reads normal when ever you reset fuel paramiters lambdas read okay for a while. Usually watched them on a drive home from work and by time i reach the motorway they are all over again esp no2 reading over .45 i know no1 is supposed to go up and down as the fueling is alterd. Has had new plugs but will try another set just to be on the safe side. However before head gasket failure no2 on engine 1 the lambdas would have a white silica film on them enfine no2 uses no water what so ever and runs really nice however when changing the cat took out no 1 lambda sensor so see the damage and again a slight white/grey colouring. So assuming its running lean therfore running hotter. Which would explain a second head failure after 18k in less than a year ?

Post cat should be over .45 normally a steady voltage between 500 to 700 mV

 

[koalar]

Been going on for two years. Maybe a full list of what's already been already tried


Induction kit ? is it back to standard.? Was it an oil type air filter.


You can never be 100% but I would doubt the injectors with all 4 spark plugs the same.


Air temperature should log very close to ambient (within a degree or two) at start up then rise slowly above as the engine warms up. Without correct reading the fuelling will be out.



You asked what the pressure should be. I believe the 8V is 3 bar. Hopefully someone can confirm this.


You say you have tried a new cap. Is that due to a vacuum when removing the cap?


If its fuel starvation which I am not 100% sure. Plugs normally go quite white or glazed. There's still a few possibility

Fuel pump. Pressure test should conform this
Fuel filter. Remove and check flow through it
Tank breather. Normally heard when removing cap or difficulty fuelling up.

 

[scott gilmour95]

No difficulty fueling up but a few forums mentioned the evap system so replaced The after market cap for peace of mind. It has been the standard air box with numerous paper/after market filters however due to being fed up of the code threw an induction kit for abit of enjoyment. Lambas have has white crusting tho ? However no fuel loss and not had change to see if i can get fuel pressure yet as my diagnostics kit is in work and was rushed off my feet today will check tomorrow lunch time

 

[koalar]

Strange post cat indicates rich running or normal but plugs show not?? you say over .45v but not exact figure.


You could reset the trim. Disconnect the post cat lambda and take it for a drive of 10 miles and re-examine the plugs


If that's the same you could try it the other way round. The system will recognise the lambda isn't working and use standard settings.


At least it would eliminate the sensors even though they are new.


You could do the same with the MAF sensor. This would be my "guess" as fits the symptoms and when they are only slightly faulty the fuel trim will run out of adjustment. As its just a "guess" I would temporary disconnect and see if things improve.

 

[scott gilmour95]

No maf sensor only a map sensor on the inlet manifold and its been swapped out twice as that was the first thought

 

[scott gilmour95]

 

[scott gilmour95]

No idea why it posted so many pics haha but i have a new code now since putting the new cat on and using a genuine pre cat sensor that came with it

 

[irc]

Quick couple of questions:
What was the actual ambient temperature when you took the photo?
Is the inlet temp sensor a genuine part?
20 degrees seems high, especially with coolant temp at 17. Possible, but slightly susicious.

 

[koalar]

Quick couple of questions:
What was the actual ambient temperature when you took the photo?
Is the inlet temp sensor a genuine part?
20 degrees seems high, especially with coolant temp at 17. Possible, but slightly susicious.

Sensors will be a few degrees out there not spot on.

Ambient temperature sensor is built into the MAP


I found the ambient fairly close to what Google says my location temperature is before I start the car but a few degree would not worry me.

P0130 from memory Is the code when you disconnect a lambda sensor. Same as if the heater element has blown in the lambda. Check the wiring and test for resistance across the heater element of the senor pins.

 

[irc]

koalar I reckon ambient should not be more than a degree or so different to underbonnet temp (which should be close-ish to outside temp before starting engine). However, I have had a temp sensor over read and make engine run ok but uneconomical.
Changed sensor for a genuine part and difference was instant.
Pattern part never threw an error, but there's a big difference between 35mpg and 50mpg.
Not suggesting that this is the problem, but would hate to overlook the possibility.

 

[scott gilmour95]

Lists ambient and an iat (intake air temp) i believe assumed the iat was in the trottlebody and thats an expensive part and map is genuine ill switch it with the other one i have in my box somewhere at dinner and see if it reads any different. I assumed ambient was atmospheric so would be the one in the wing mirror as i know that is the case with vw its the sensor in the front bumper and they throw up engine lights when they are down

 

[irc]

Just had a chance to check invoices for parts I changed. It was the MAP sensor, but it was only the temperature part which was giving strange readings. The pattern part was under £10, the genuine part was £28. We discovered the problem when we swapped a secondhand throttle body to try to eliminate it. Temperature read way higher on pattern part, so we swapped throttle body back and installed genuine MAP sensor.

Leads me to another question... Are you still using your original throttle body? The secondhand one we tried had a leak. Found the leak after fitting it, but the car it came off was running ok-ish. Donor was accident damaged at rear so not caused by that.
Not suggesting you change it yet, but knowing may help to narrow down problem.

 

[scott gilmour95]

Still on original it has been off a few times cleaned and soaked for a few hours but the gasket still seemed nice and flexable put my donor map sensor on today is a genuine bosch unit amd pretty much same reading

 

[scott gilmour95]

Oh and my p1172 has come back but just not triggered engine warning light yet