Clearing adaptations with INPA after M54 engine swap

[mrscalex]

Before I embark on further troubleshooting with my misfire errors following my engine swap I want to clear the adaptations. I'm thinking the replacement engine is currently running with the old engine's adaptations. It might just sort things out. The engine was running perfectly in the donor car.

I know my way round INPA but I want to make sure I get the procedure exactly right.

I believe a reset should be done with the engine off but with ignition on?

Do I then just start the engine? Or do I need to withdraw the key before replacing and starting the engine? I know all these things might make a difference.

Also, should I reset all adaptations? Or just selected ones?

 

[Dobiwallah]

This is what youtube says. I can't see it myself, YT is blocked on my work:

 

[mrscalex]

This is what youtube says. I can't see it myself, YT is blocked on my work:

Cheers. But I saw that already and really it just shows you were to find the buttons.

 

[NZ00Z3]

The adaptions reset when you hit the button on the screen, there is no need to turn the ignition off and on again. Have even reset them (by mistake) with the engine running, no problems, just a tone change from the engine.

 

[mrscalex]

The adaptions reset when you hit the button on the screen, there is no need to turn the ignition off and on again. Have even reset them (by mistake) with the engine running, no problems, just a tone change from the engine.

Excellent sir. Thank you.

Realistically do you think the misfire could be caused by adaptations from the old engine? The replacement engine has only been run at idle for about 5 mins a time a handful of occasions so has had no time to adjust itself.

 

[NZ00Z3]

Clearing the adaptions will help. Its more likely to be due to something that has changed during the engine exchange, spark plug, coil pack, injector (dirty or not seated correctly), inlet manifold gasket that fell off one runner during install giving massive air let (I have had the gasket partly fall off, but noticed it at the time, so it was corrected), etc

 

[mrscalex]

I disturbed very little when I put the engine in. It went in with literally everything still bolted on. Including complete inlet system and exhaust manifolds.

The only thing I remade apart from the wet (p/s, coolant, fuel) connections was the air inlet system and some rotted vacuum connections.

I suspect this will be a vacuum leak if not cured by the adaptations reset. It's quite possible I missed some rotted rubber which got disturbed.

INPA was showing a distressed cylinder 6 as well as cylinder 4 which had the DME error (242 burn fail).

The donor engine was running sweet as a nut before it was pulled.

 

[Brian H]

Where are you thinking the adaptations in the new engine are being stored?

 

[mrscalex]

Where are you thinking the adaptations in the new engine are being stored?

I'm not. The point is the adaptations from the old engine are most likely to be the ones still in the DME. The car has not been driven or even run up enough to adjust the adaptations around the new engine - I suspect. I'm no expert on adaptations but the concensus seems to be they take 100+ miles to settle. So clearly not something that happens on the first turn of the key with a new engine.

The DME must surely still think the old engine is still in there and could be applying a completely spurious set of adaptations to the new engine. Which might be causing the misfire.

 

[Brian H]

I'm not. The point is the adaptations from the old engine are most likely to be the ones still in the DME. The car has not been driven or even run up enough to adjust the adaptations around the new engine - I suspect. I'm no expert on adaptations but the concensus seems to be they take 100+ miles to settle. So clearly not something that happens on the first turn of the key with a new engine.

The DME must surely still think the old engine is still in there and could be applying a completely spurious set of adaptations to the new engine. Which might be causing the misfire.

Makes sense now, I read it as your new engine still had the old adaptations

 

[mrscalex]

Mystery solved. And I thought it was worth sharing.

I cleared the adaptations, changed the spark plugs, changed the MAF, swapped the coils, checked the intake boot for cracks, checked the upper vacuum connections for cracks and misfire still there.

I picked up one clue along the way that I didn't get the significance of at the time. The plug on cylinder 4 (the misfiring one) came out with a glistening electrode that quickly evaporated... I'm guessing unburnt fuel.

I thought again about where the error may have crept in. Remembering this engine was running lovely in the breaker. It either had to be a part of the engine that was an unknown commodity not carried over from the donor car but on the project car (which had never run - it came with a dead engine). Or something I bust on the donor engine as it moved over.

So I had another think about the former theory. Fuel pump, fuel filter and DME came to mind as to what could be faulty on the project car. And what wasn't brought across from the known good donor.

So the DME came out with the intention of opening it up to look for a fried component. But I never got that far. One of the pins was corroded. Not easy to see but look for subtly different colour of the bottom left pin.

And further more when I looked up what the pin did it controlled the coil of cylinder 4. The misfiring one! A quick clean up with some emery cloth and now running smooth as you like! Phew.

I guess the petrol on the spark plug was fuel being injected and not igniting due to the unpowered coil. The error was a burn fail. I guess that's exactly what was happening. Hindsight's a great thing isn't it!

I can't help wondering if that corroded pin had been like it when the project car was still running with the old engine before it threw the lump of metal that shot through the sump - the one thing I could tell from the dead engine. Had the previous owner run the car for a long period with a dead cylinder? Can a dead cylinder carried for long enough cause a break up of the engine internally? Possibly from an inbalance and loosening a component like a con rod bolt? I'm struggling to believe that but you never know.

 

[oldcarman]

Rob, I stand to be corrected but my take is that unburned fuel in cyl 4 was not being completely cleared on the exhaust stroke and gradually fills the cylinder completely or near complete which causes a rise in compression in the cylinder and that puts unreal strain on the con rod which shatters and takes out your sump. Had this happen on my Porsche 924 but luckily the engine didn't fire and when I took out the plug gas flowed out. I used the starter to evacuate the fuel and it shot about twenty feet from the car. I hope this makes sense, JIM

 

[mrscalex]

Rob, I stand to be corrected but my take is that unburned fuel in cyl 4 was not being completely cleared on the exhaust stroke and gradually fills the cylinder completely or near complete which causes a rise in compression in the cylinder and that puts unreal strain on the con rod which shatters and takes out your sump. Had this happen on my Porsche 924 but luckily the engine didn't fire and when I took out the plug gas flowed out. I used the starter to evacuate the fuel and it shot about twenty feet from the car. I hope this makes sense, JIM

Sounds reasonable.

Fortunately the replacement engine was run very little with the misfire issue caused by the original DME, a few minutes at idle. So I'm trusting no damage.

But it might well be what took the original engine out.

 

[oldcarman]

If it was only idled for short periods you should be fine with the new engine, but I'd bet that the scenario I posted likely took out the rod and the pan!! Good luck with the MOT, JIM

 

[Dobiwallah]

Well done mrscalex! Hard to find this fault. These are the findings you can tap yourself on the shoulder and say to yourself I did it!

 

[mrscalex]

Well done mrscalex! Hard to find this fault. These are the findings you can tap yourself on the shoulder and say to yourself I did it!

I was just pleased to sort it! Unbelieveable if it really was a crappy bit of corrosion that took the old engine out!

 

[Lee]

That's a good find, worth remembering in future to check the pins for corrosion if anyone gets a misfire.

 

[mrscalex]

That's a good find, worth remembering in future to check the pins for corrosion if anyone gets a misfire.

Mate, I can not tell you how pleased I was to find that. I was about to embark on a ground-up check using this excellent post. I could have spent hours over weeks!

http://www.bimmerfest.com/forums/showpost.php?p=5804284&postcount=15

Ironically it doesn't mention the DME!

But I stopped myself in my tracks and forced myself to look at all the evidence again. So glad I did! Logically it seemed like it might well be the DME but I was far from convinced when I started.

Bimmerfest also has a number of threads on troublesome DMEs although they are more focused on opening up and fixing fried components. But do also mention corrosion/ingress. I actually managed to fix my domestic boiler PCB for a blown transformer recently. So it was those threads that lead me to the DME really.

I guess if you were a BMW dealer you'd have all the electrical test kit to pinpoint faults like this straightaway. Shame all of the dealers I have experience of wouldn't have a clue how to use it

 

[handsomejackuk]

nice spotting Rob, i have to get my head around inpa sometime... looks like its a useful piece of kit to have in the toolbox... love using Torque, and my permanant bluetooth obd connection on my 1998 1.9 is proving so handy.. doesnt always connect immediately but once it does its soo good to see actual engine tempertaure when on the move, and so many other things 02 sensors, intake temp, fuel trims maf readings vacuum and loads of other things... must also have a go at carly to that looks good


21200872_353840258385727_7698799074940566206_o by handsomejackuk, on Flickr



21106359_353841751718911_6722572238929589318_n by handsomejackuk, on Flickr

 

[mrscalex]

nice spotting Rob, i have to get my head around inpa sometime... looks like its a useful piece of kit to have in the toolbox... love using Torque, and my permanant bluetooth obd connection on my 1998 1.9 is proving so handy.. doesnt always connect immediately but once it does its soo good to see actual engine tempertaure when on the move, and so many other things 02 sensors, intake temp, fuel trims maf readings vacuum and loads of other things... must also have a go at carly to that looks good

It's easy to use. Although you'd need to be a mechanic or very serious enthusiast to understand all the readings.

NCS Expert for coding frightens people, including me previously but it's perfectly useable.

I could show you both in 20 minutes in MacDonalds J24 car park

You just need an old laptop. And a set of cables which will come with the software. It can be a bit fiddly to setup but if you buy from the right source (about £40) you will get personal support, including over a live screen share if required I believe.