spare mbe ecu anyone?
Discussion
I could do with a bit of help in diagnosing a fault with my sagaris, to briefly exlpain, I have a missfire problem when under load at low rpm in a high gear, I did think this may be simply because I needed to change down a gear, as the engine was choking up when putting on to much throttle before the engine comes on cam, but feel affter seeking other opinions that this is to far pronounced to be someting as simple as that.
I have changed the ht leads and coil for new items, and also fitted new spark plugs with correct gaps set, and today went out with my mate dave, dnb on here, who is an electronics/ecu boffin,who sat in the passenger seat with the laptop connected to the ecu, and he found that when I make the car missfire by introducing throttle at low rpm, the missfire appears on both banks, ie, 123 and 456, this being shown by the llambda voltages returning to zero, dave can explain the technical sides much better than myself
so, we have come to the conclusion that if the ht leads and coil are in good condition, and the missfire being on both banks of clinders, that there may be a fault in the coil driver within the ecu itself, so, does anyone have a spare mbe ecu that will fit an 05 sag, 3 plug type, that I could use to prove the theory right or wrong, either to hire for a week, or even purchase if the price is right.
on another note, people who have opted for the omex, or syvecs ecu, does this mate up with the dash ecu so that you still operate the pod display in the same manner as with the mbe set up, without having to reset an error code every time you turn on the car?
I have changed the ht leads and coil for new items, and also fitted new spark plugs with correct gaps set, and today went out with my mate dave, dnb on here, who is an electronics/ecu boffin,who sat in the passenger seat with the laptop connected to the ecu, and he found that when I make the car missfire by introducing throttle at low rpm, the missfire appears on both banks, ie, 123 and 456, this being shown by the llambda voltages returning to zero, dave can explain the technical sides much better than myself
so, we have come to the conclusion that if the ht leads and coil are in good condition, and the missfire being on both banks of clinders, that there may be a fault in the coil driver within the ecu itself, so, does anyone have a spare mbe ecu that will fit an 05 sag, 3 plug type, that I could use to prove the theory right or wrong, either to hire for a week, or even purchase if the price is right.
on another note, people who have opted for the omex, or syvecs ecu, does this mate up with the dash ecu so that you still operate the pod display in the same manner as with the mbe set up, without having to reset an error code every time you turn on the car?
Here's a data log of the misfire event Clive describes.
The lambda readings occur slightly delayed due to transit time of the gasses from the engine to the sensors, so in all likelihood as soon as the throttle is opened, the misfire begins.
The misfire event itself feels just like an extremely aggressive traction control system has been turned on. It is predictable and repeatable, leading me to think it is perhaps an issue with the ignition table having to be able to do two different things in two different cases when the sensor suite on the engine can't tell them apart.
All the sensor readings appear to make sense and line up with expectations, so things would appear to be being measured correctly.
The lambda readings occur slightly delayed due to transit time of the gasses from the engine to the sensors, so in all likelihood as soon as the throttle is opened, the misfire begins.
The misfire event itself feels just like an extremely aggressive traction control system has been turned on. It is predictable and repeatable, leading me to think it is perhaps an issue with the ignition table having to be able to do two different things in two different cases when the sensor suite on the engine can't tell them apart.
All the sensor readings appear to make sense and line up with expectations, so things would appear to be being measured correctly.
Edited by dnb on Monday 9th January 01:07
Getsis said:
If you can get to Mirfield West Yorkshire you can use my old Tamora MBE ECU you will just need to swap over the EPROM chip.
The Syvecs doesn't affect how the Dash ecu is controled.
I'm in Norway so can't post out but someone is at the house for collection.
CliveThe Syvecs doesn't affect how the Dash ecu is controled.
I'm in Norway so can't post out but someone is at the house for collection.
I can pick this up and then post it to you.
Getsis, thanks for your kind offer, if you are happy for graham to collect and post to me, as I am down south on the isle of wight that will be great, it will cetainly prove the fault one way or another, then I will send back to Yorkshire, or Norway if you prefer.
I read somewhere that you may be at Chatsworth this year, so will seek you out as I`ll owe you a drink
Graham, yes please mate, very kind of you, let me know postage ect and I`ll sort you out, and ply you with ale at the manor house soon.
perhaps you can mail getsis for address to collect, and I`ll pm you my address for postage.
thanks gents, p/hds to the resuce.
I read somewhere that you may be at Chatsworth this year, so will seek you out as I`ll owe you a drink
Graham, yes please mate, very kind of you, let me know postage ect and I`ll sort you out, and ply you with ale at the manor house soon.
perhaps you can mail getsis for address to collect, and I`ll pm you my address for postage.
thanks gents, p/hds to the resuce.No need to post it back I'm in no rush so just bring it to Chatsworth. It was checked over just prior to taking it out and a new dallas chip installed so there should be no faults with it. In fact thinking about it your problem sounds similiar to what I had happen a couple of times with the Tam whan the engine was cold, hence the dallas chip change and ECU repair. £205 for it sorting.
problems now all solved, so a breif explanation as to what the problems were,
after receiving a spare mbe ecu from Getsis, dnb removed the chip and fitted the chip from my ecu, and whilst I was playing I decided to fit the new ht leads that had arrived from Power then take the car for a test drive.
before I removed the ht leads from the engine, I noticed that several of the caps had popped up slightly on the cam cover, strange as these were all fitted in correctly, so I swapped over the ht leads and found that the new leads didn`t want to seat correctly on the top lip of the cam cover at all, I have an aftermarket cam cover on the engine, so I dug out the original and tried the leads in this and they fitted a treat, so out with a round file and proceeded to file a chamfer all round the inside of each plug hole in the cover, as this is made from plastic, then with generous amounts of silicon spray the leads all fitted in nicely.
turn the key and everything is hunky dory, a few miles up the road and tickover is nice at 900rpm, pick up is instant, job done, returned home, swapped ecu`s back over and car still goes as it should, so no ecu problems just pesky ht leads, which is strange as the car started developing a miss fire some months ago, ages after the new cam cover was fitted, so can only deduce that with time and lots of heat, somehow the rubber caps had slowly pushed up out of the holes ever so slightly causing missfire on 2 or more cylinders when under heavy load, ie low rpm high gear, so the spark at the plug just wasn`t strong enough to cope under those conditions.
ended up a very simple fix, and can only say that if I drove it on a more regular basis I would have found the fault a lot quicker, having not used the sag since september I started to forget what it sounded and felt like!!
many thanks to getsis for the loan of the ecu, and graham for collecting and posting to me, will see you both at Chatsworth.
not forgeting professor Dnb, thanks for your help mate.
after receiving a spare mbe ecu from Getsis, dnb removed the chip and fitted the chip from my ecu, and whilst I was playing I decided to fit the new ht leads that had arrived from Power then take the car for a test drive.
before I removed the ht leads from the engine, I noticed that several of the caps had popped up slightly on the cam cover, strange as these were all fitted in correctly, so I swapped over the ht leads and found that the new leads didn`t want to seat correctly on the top lip of the cam cover at all, I have an aftermarket cam cover on the engine, so I dug out the original and tried the leads in this and they fitted a treat, so out with a round file and proceeded to file a chamfer all round the inside of each plug hole in the cover, as this is made from plastic, then with generous amounts of silicon spray the leads all fitted in nicely.
turn the key and everything is hunky dory, a few miles up the road and tickover is nice at 900rpm, pick up is instant, job done, returned home, swapped ecu`s back over and car still goes as it should, so no ecu problems just pesky ht leads, which is strange as the car started developing a miss fire some months ago, ages after the new cam cover was fitted, so can only deduce that with time and lots of heat, somehow the rubber caps had slowly pushed up out of the holes ever so slightly causing missfire on 2 or more cylinders when under heavy load, ie low rpm high gear, so the spark at the plug just wasn`t strong enough to cope under those conditions.
ended up a very simple fix, and can only say that if I drove it on a more regular basis I would have found the fault a lot quicker, having not used the sag since september I started to forget what it sounded and felt like!!
many thanks to getsis for the loan of the ecu, and graham for collecting and posting to me, will see you both at Chatsworth.
not forgeting professor Dnb, thanks for your help mate.
Triumph 3 cylinder bike engines used to suffer from something similar:
The Coils (individual, 1 per cylinder) made a very tight seal with the cam cover - but not tight enough to stop water getting past them into the plug well.
When the engine next got hot enough to boil the water, the steam pressure was enough to blow the coil up off the spark plug.
It was solved with a small hole in each coil seal to relieve the pressure.
The Coils (individual, 1 per cylinder) made a very tight seal with the cam cover - but not tight enough to stop water getting past them into the plug well.
When the engine next got hot enough to boil the water, the steam pressure was enough to blow the coil up off the spark plug.
It was solved with a small hole in each coil seal to relieve the pressure.
the people I used are, www.merlinmotorsport.co.uk I removed all of the oil pipes and sent them off to them so that they could make a matching set, things like getting the fittings on each end of the pipe in the correct orientation to each other means you can`t just ask for a hose 18" long with a 3/4"bsp fitting on either end, so they have to be made copying the old pipes.
the only pipe that couldn`t be replaced was the sump to oil tank pipe, the fitting on the end of this that fits into the tank is so big that they couldn`t find anyone who made anodised aluminium fittings for it, apparently this size fitting is normally found on large lorries.
the only pipe that couldn`t be replaced was the sump to oil tank pipe, the fitting on the end of this that fits into the tank is so big that they couldn`t find anyone who made anodised aluminium fittings for it, apparently this size fitting is normally found on large lorries.
[ask_big_favour] Thanks Clive... wondering how long it takes re:sending them off and waiting for new pipes returned, and then wondering if you still have all your old pipes in a bag somewhere which could be sent off again to get new ones made up, or even if merlin might have details of what they made for you.... [/end_ask_big_favour]
If you still have all the old pipes, and I could 'borrow' them, or if there's full details on your invoice so I could order a set, that would be brilliant. PM me your telno if it's easier to chat about it.
If you still have all the old pipes, and I could 'borrow' them, or if there's full details on your invoice so I could order a set, that would be brilliant. PM me your telno if it's easier to chat about it.
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