Ecu Help needed
Discussion
Hi
I've been having a problem with erratic fueling recently causing rough running at part throttle on my 4.2.
When the Ecu was connected to the laptop I noticed that throttle pot 1 would jump up and down about 2% even without the engine running. So down to 14.8 and up to 18.8.
I checked and swapped the throttle pots and they both had a constant 5v supply and when the throttle was opened the voltage signal increased smoothly as it should.
Next step was to try my Ecu on another Cerbera which was known to be ok and the fault was transferred, with the same throttle pot jumping. So I sent my Ecu away to MBE Systems and it was returned with no faults found!
Has anybody had a similar problem and found a solution, or knows of someone else who can repair them.
I would prefer to have my Ecu repaired rather than try and source a secondhand one but if nobody can repair it what other choice do I have other than go with a aftermarket setup like Emerald.
I've been having a problem with erratic fueling recently causing rough running at part throttle on my 4.2.
When the Ecu was connected to the laptop I noticed that throttle pot 1 would jump up and down about 2% even without the engine running. So down to 14.8 and up to 18.8.
I checked and swapped the throttle pots and they both had a constant 5v supply and when the throttle was opened the voltage signal increased smoothly as it should.
Next step was to try my Ecu on another Cerbera which was known to be ok and the fault was transferred, with the same throttle pot jumping. So I sent my Ecu away to MBE Systems and it was returned with no faults found!
Has anybody had a similar problem and found a solution, or knows of someone else who can repair them.
I would prefer to have my Ecu repaired rather than try and source a secondhand one but if nobody can repair it what other choice do I have other than go with a aftermarket setup like Emerald.
Hi Will
I checked the pins and they all look in excellent condition. Also removed the pcb and checked both sides and there are no obvious signs of damage. I've done my best to check for dry joints but everything is covered in what looks like clear lacquer and the joints are so small it's hard to see.
How's your running since we did the valves, have you noticed any difference?
I checked the pins and they all look in excellent condition. Also removed the pcb and checked both sides and there are no obvious signs of damage. I've done my best to check for dry joints but everything is covered in what looks like clear lacquer and the joints are so small it's hard to see.
How's your running since we did the valves, have you noticed any difference?
Well it runs fine at the software says it's all good too. I haven't been able to drive it due to 2 bleed screws shearing off in the N/S rear brake caliper. It briefly looked repairable but after getting the screws out and cleaning the threads up there wasn't enough metal left to torque the screws up properly. Work has separated me from the car at the moment but I have a spare caliper from a breaker's yard waiting to go on when I get back. Looks like I'm going to miss Burghley too.
Vee8ight said:
Mine jumps about a bit too, should we meet up and compare?
It would be good to meet up, I was half expecting to see you at Doddington yesterday.When and where shall we meet I'm near Coningsby.
Does your jump about without the engine running, mines enough to alter the fueling. One thing I have noticed is that it's much more noticeable when using the new software that was written by EvoOlli.
I think I have exactly the same problem. I have been chasing a rough running issue for some time now and have recently gone right through everything checking valve clearances and inlet / exhaust leaks. My Cerb is quite rough at part throttle ( fine on full throttle), particularly less than 2,000 RPM, it cleans up above this RPM but I can still just feel it at cruising speed. At the moment I get round it by keeping either the gas on or by completely backing off the throttle in light traffic.
Having ruled out the air leaks and valve clearances and having changed plug leads etc.. I'd moved on to throttle pots, disconnecting either makes no difference, but when connected to the diagnostic software I do appear to have an erratic Throttle 1 reading, which can vary by as much as +/- 4% and if I hold the revs at 1600-1800RPm I can feel the rough spot and the throttle pot one is jumping as it does it. This is also backed up by the Adaptive flicking, so I'm sure it's a fueling issue. I would love to try a different ECU as you have to see if it cures it. I would of course much prefer it not to be ECU connected and until I saw your thread was thinking about buying two new throttle pots. Although I'm a bit reluctant to as I can’t exactly tie it down to a throttle pot fault.
Having ruled out the air leaks and valve clearances and having changed plug leads etc.. I'd moved on to throttle pots, disconnecting either makes no difference, but when connected to the diagnostic software I do appear to have an erratic Throttle 1 reading, which can vary by as much as +/- 4% and if I hold the revs at 1600-1800RPm I can feel the rough spot and the throttle pot one is jumping as it does it. This is also backed up by the Adaptive flicking, so I'm sure it's a fueling issue. I would love to try a different ECU as you have to see if it cures it. I would of course much prefer it not to be ECU connected and until I saw your thread was thinking about buying two new throttle pots. Although I'm a bit reluctant to as I can’t exactly tie it down to a throttle pot fault.
Hi when you examine the adaptive maps what do they look like, mine can be -15/20 and then jump to +10/15 on the next throttle position and is similar on both banks. I have been looking at it today and noticed that lambda 2 is slower to react than lambda 1 but once it starts to move it fluctuates up and down ok. I'm wondering if it would be worth me changing both, tonight I removed lambda 2 and heated it until glowing with a blow torch and I'll do the other in the morning and see if there's any difference in the adaptives.
If I reset my adaptives it will run ok for a while then gradually deteriorate.
If I reset my adaptives it will run ok for a while then gradually deteriorate.
If your pots varies more than +\- 5, I'd say your pots are ruined. Lazy lambdas can cause adaptives problems as can cracked manifolds
A good thrash, and I mean damn good, can fix lambdas, it did mine.
The standard map on a 4.2 is lumpy under 3k. My pots still dance about a bit, but only about 3-4, more at idle than with revs
Daz
A good thrash, and I mean damn good, can fix lambdas, it did mine.
The standard map on a 4.2 is lumpy under 3k. My pots still dance about a bit, but only about 3-4, more at idle than with revs
Daz
Hi, my adaptive are quite good. Between 0 +10 on even bank and 0~10 on the odd bank.I only have Aides software on a tablet rather than a laptop and I'm not sure how or if you can record the data. Both Lambas appear normal as well. I will be going to Burghley so would welcome the opportunity to discuss/compare with anyone.
Adambul said:
Yes I've seen the option but I`m then not sure how you view it. It may just be me being thick!
its best to download the file to a desktop comp or laptop. its an excel file with all parameters recorded. you can find the file in the app directory.i can show you on sunday if we meet. Silver Cerb L40 UDD.
Daz
I've been setting mine up again this afternoon and have tried something different after speaking to joolz.
I balanced each banks airflow and double and triple checked it so each bank is flowing 20kg/hr then put both throttle pots on 15.5% car runs ok but have high adaptives at idle +15 take it for a run and rough running is alot better. Then gradually increased the throttle pots 15.9, 16.6, 16.9, 17.3. As soon as I tried 17.3% the rough running was noticeably worse, with 16.6% being about the best.
Joolz idea was to try and not get to concerned about 0 adaptives and just let the car tell you when its most happy by how it runs. I'll run it for a while then download the adaptives again just to see what's happening but if it's still running ok and some areas of the adaptive map are high or low then so be it.
I will be at Burghley in a green Cerbera R481BLD, I will try and find you Adam and I'll see you on Saturday Daz.
I balanced each banks airflow and double and triple checked it so each bank is flowing 20kg/hr then put both throttle pots on 15.5% car runs ok but have high adaptives at idle +15 take it for a run and rough running is alot better. Then gradually increased the throttle pots 15.9, 16.6, 16.9, 17.3. As soon as I tried 17.3% the rough running was noticeably worse, with 16.6% being about the best.
Joolz idea was to try and not get to concerned about 0 adaptives and just let the car tell you when its most happy by how it runs. I'll run it for a while then download the adaptives again just to see what's happening but if it's still running ok and some areas of the adaptive map are high or low then so be it.
I will be at Burghley in a green Cerbera R481BLD, I will try and find you Adam and I'll see you on Saturday Daz.
That sounds interesting as my Throttle Pots are well in to the 17's at idle so i'll knock them back a bit and see how it responds. I spent some time balancing mine mechanically having invested in an airflow meter and it definitely improved things. After i'd got mine balanced reasonably well I noticed my adaptives were all over the place so i reset them and apart from initially stalling and having to hold the revs up until it sorted itself out, the adaptive readings dramatically improved. look forward to discussing further on Sunday...
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