Engine not firing on even bank
Discussion
On the cusp of roadworthiness, but developed a new fault...Todays MOT now cancelled, which is frustrating.
I noticed last night that the engine was running a little rough and it started stalling at idle. I took my IR gun and right enough the even bank was cold at the manifold for each cylinder. Initially I thought it was probably a coil pack, however after much cleaning of the LT connection and checking the HT leads were seated at both ends, there was no change in the running.
Next I pulled cylinder 2, and put a spare sparkplug in it - and of course I have a spark.
I read this interesting thread
https://www.pistonheads.com/gassing/topic.asp?h=0&... which essentally dealt with a simillar situation.
I looked at the supply (red wire) to all the injectors, and I have 12V at them.
I've checked the continuity of the blue wire between the injectors, and it's good, and I've checked the continuity of the wire between cylinder 8's injector and the wire at the ECU plug, and it's good.
The latter check I also unclipped the loom from the bulkhead and gave it a good waggle while cheking the contiutity between the injector end and the plug at the ECU. This came up good.
The one thing I have not specifically checked is how good the battery is. It cranks it over fine, but I do recall the Cerbera is sensitive to battery condition.
Any other ideas or experiences anyone can share?
Thanks
I noticed last night that the engine was running a little rough and it started stalling at idle. I took my IR gun and right enough the even bank was cold at the manifold for each cylinder. Initially I thought it was probably a coil pack, however after much cleaning of the LT connection and checking the HT leads were seated at both ends, there was no change in the running.
Next I pulled cylinder 2, and put a spare sparkplug in it - and of course I have a spark.
I read this interesting thread
https://www.pistonheads.com/gassing/topic.asp?h=0&... which essentally dealt with a simillar situation.
I looked at the supply (red wire) to all the injectors, and I have 12V at them.
I've checked the continuity of the blue wire between the injectors, and it's good, and I've checked the continuity of the wire between cylinder 8's injector and the wire at the ECU plug, and it's good.
The latter check I also unclipped the loom from the bulkhead and gave it a good waggle while cheking the contiutity between the injector end and the plug at the ECU. This came up good.
The one thing I have not specifically checked is how good the battery is. It cranks it over fine, but I do recall the Cerbera is sensitive to battery condition.
Any other ideas or experiences anyone can share?
Thanks
Was it running fine initially and has since got worse and worse to the point of stalling?
Have you got any diagnostic software .. if you do, have a look at the adaptive tables. If one table has +37% and the other -37% then you've got the lambda plugs swapped over (if you removed them during the clutch change then this is favourite)
refit lambdas/plugs to the correct side and reset the adaptives, and fault codes.
Note lambda wires are marked on yellow labels on the loom and the plugs are marked with felt tip pen as o and e for odd and even banks. People see the o marking and think it means offside, which is the wrong (even) side ...
Have you got any diagnostic software .. if you do, have a look at the adaptive tables. If one table has +37% and the other -37% then you've got the lambda plugs swapped over (if you removed them during the clutch change then this is favourite)
refit lambdas/plugs to the correct side and reset the adaptives, and fault codes.
Note lambda wires are marked on yellow labels on the loom and the plugs are marked with felt tip pen as o and e for odd and even banks. People see the o marking and think it means offside, which is the wrong (even) side ...
BIG thanks Joolz!
Got it running this evening after swapping the lambda sensors over.
Not quite my error as they were marked O and E but on the sensor side of the plug. I’m assume at some stage they have somehow been switched. I had unscrewed them in this case rather than unplug them. I couldn’t see ant markings or labels on the loom side, so took a punt and swapped.
Discovered my tablet won’t connect to the ECU. I resorted to unhooking the battery and leaving it on the basis that the pill battery on the ECU may well be dead.
Hooked it back up, started it and after a while the even bank seems to respond and I’m getting pretty even temperatures at each port.
Next stop booking an MOT...
Got it running this evening after swapping the lambda sensors over.
Not quite my error as they were marked O and E but on the sensor side of the plug. I’m assume at some stage they have somehow been switched. I had unscrewed them in this case rather than unplug them. I couldn’t see ant markings or labels on the loom side, so took a punt and swapped.
Discovered my tablet won’t connect to the ECU. I resorted to unhooking the battery and leaving it on the basis that the pill battery on the ECU may well be dead.
Hooked it back up, started it and after a while the even bank seems to respond and I’m getting pretty even temperatures at each port.
Next stop booking an MOT...
Note to self: Do not utter the word MOT in the presence of this car..
Not booked it in yet, but it's not running all that well. I did have some success in getting EvoOlli's software hooked up and connected. On my first hit I got the following, which doesn't look too great.
I reset the fault codes as it's not been looked at in a long time, and they all came back up immediately. Now looking at it I should have possibly also rest the log history also to clear that list?
I also noticed that the 'crank sensor' status turned red on occassion.
Had a shot at looking at the scope, and also recorded some data.
Not really quite sure what to make of the Lambda's in the middle fo the trace.
On the positive side, I can now see what is happening, however it looks like I have a bit of work to do.
If I increased the revs to the high 1300's the battery voltage picks up, to over 13V so I assume that's reasonably healthly.
At this stage I've not run it right up to temperature, as I thought I'd take stock first.
Not booked it in yet, but it's not running all that well. I did have some success in getting EvoOlli's software hooked up and connected. On my first hit I got the following, which doesn't look too great.
I reset the fault codes as it's not been looked at in a long time, and they all came back up immediately. Now looking at it I should have possibly also rest the log history also to clear that list?
I also noticed that the 'crank sensor' status turned red on occassion.
Had a shot at looking at the scope, and also recorded some data.
Not really quite sure what to make of the Lambda's in the middle fo the trace.
On the positive side, I can now see what is happening, however it looks like I have a bit of work to do.
If I increased the revs to the high 1300's the battery voltage picks up, to over 13V so I assume that's reasonably healthly.
At this stage I've not run it right up to temperature, as I thought I'd take stock first.
Edited by Bogsye on Monday 27th July 21:34
Get it up to temperature then worry about the lambdas. Extra enrichment during warmup will have an effect. The alternator not charging the battery at idle is pretty common, also best to check voltage with a meter rather than software reading. Your throttle pots are wrong too, they should read the same. Either set the engine up properly (many guides on here) or get it to Jools.
Sounds like you have an intermittent problem and if you say initially the ports were cold then that would't scream lambda problem to me, that means the whole bank is off and whats strange about these ajp's is they fire 2 cyls at once/waste spark but the one fired into the exh is the polar opposite of the one that gets fired to ignite the fuel and so not strictly waste but tuned and for every 720 degrees you get 8 bangs and 8 pops down the exhaust it maybe possible to see A spark but how do you know if she's popping when she should be banging? ....It's late i'l have a think on it.
^^ not sure what all that stuff about popping and banging is all about, it makes no odds. Best ignored.
Anyway, that aside, you can't read much into your pics .. if that's at idle at 1400rpm then that obviously needs addressing, as does the apparent inbalance in throttle position sensor values.
Also on the trace the flatline lambdas corresponds with a rise in engine speed but no apparent large rise in throttle values though you might be holding them open slightly but you haven't said it's at that point. So you need to work out why that speed increase was if you didn't command it. The lambdas immediately beforehand were cycling, although not a nice aggressive spiking trace but that might be the sample rate of the software I don't know, but they were cycling so working to some degree.
More precise info required, or take it somewhere to have it set up for you.
Go back to first principles on your engine setup if you want to attack it yourself.
Anyway, that aside, you can't read much into your pics .. if that's at idle at 1400rpm then that obviously needs addressing, as does the apparent inbalance in throttle position sensor values.
Also on the trace the flatline lambdas corresponds with a rise in engine speed but no apparent large rise in throttle values though you might be holding them open slightly but you haven't said it's at that point. So you need to work out why that speed increase was if you didn't command it. The lambdas immediately beforehand were cycling, although not a nice aggressive spiking trace but that might be the sample rate of the software I don't know, but they were cycling so working to some degree.
More precise info required, or take it somewhere to have it set up for you.
Go back to first principles on your engine setup if you want to attack it yourself.
Thanks for the input. I had a practise shot at improving it today. Made some in roads with familiarising myself with the process.
Cleared the faults and none came back, which was good.
Tried to adjust the TP’s but it’s more like 20% I get rather than the 16% I’m aiming for. However when I tried to improve the adaptives I struggled as the threads on the throttle link are a bit stiff (still on ball joints). I’ll measure that and then strip and clean it so that adjustment is a bit easier.
Slightly frustrating but in fairness it’s a technique and process that needs a bit of practise. I also need to improve the location of my laptop to make it less like a game of twister.
In answer to the rpm rise in my graph that was me opening the throttle to see how it responded.
I’ll hopefully get a bit of time on it tomorrow and see it I can get it tomorrow improved.
Main issue is to get an MOT I’ll need it running fairly well or the emissions could be a bit tricky.
Thanks again
Cleared the faults and none came back, which was good.
Tried to adjust the TP’s but it’s more like 20% I get rather than the 16% I’m aiming for. However when I tried to improve the adaptives I struggled as the threads on the throttle link are a bit stiff (still on ball joints). I’ll measure that and then strip and clean it so that adjustment is a bit easier.
Slightly frustrating but in fairness it’s a technique and process that needs a bit of practise. I also need to improve the location of my laptop to make it less like a game of twister.
In answer to the rpm rise in my graph that was me opening the throttle to see how it responded.
I’ll hopefully get a bit of time on it tomorrow and see it I can get it tomorrow improved.
Main issue is to get an MOT I’ll need it running fairly well or the emissions could be a bit tricky.
Thanks again
Thanks all - I did just that and took my monitor from the study, and got it positioned reasonably well.
I sorted out the throttle link bar, so that adjusts properly.
Got the engine warmed up nicely, and made some adjustments. That was going okay, until one of the lambda's decided to look a bit unresponsive.
On the scope view Lambda 2 is spikey and Lambda 1 is very flat. 0.1V
It also shows AFR faulting on both odd and even - not sure if that would clear if I reset it.
Bit a of a nuisance really, so I've stopped for the day.
On the face of it, I'm assuming I should replace the offending lambda sensor. Is it prudent to do these as pairs?
Quite tempted to throw it into a garage to get it done and MOT'd, however I don;t think I'm falling over Cerbera specialists here in Glasgow.
I sorted out the throttle link bar, so that adjusts properly.
Got the engine warmed up nicely, and made some adjustments. That was going okay, until one of the lambda's decided to look a bit unresponsive.
On the scope view Lambda 2 is spikey and Lambda 1 is very flat. 0.1V
It also shows AFR faulting on both odd and even - not sure if that would clear if I reset it.
Bit a of a nuisance really, so I've stopped for the day.
On the face of it, I'm assuming I should replace the offending lambda sensor. Is it prudent to do these as pairs?
Quite tempted to throw it into a garage to get it done and MOT'd, however I don;t think I'm falling over Cerbera specialists here in Glasgow.
Try Kenneth Brown in Hillington https://www.kbmengineering.co.uk/ He's looked after my Cerbera since 2005. Last time I was there he was tuning a Dino and had just finished setting up an original GT40. Good Guy.
notaping said:
Try Kenneth Brown in Hillington https://www.kbmengineering.co.uk/ He's looked after my Cerbera since 2005. Last time I was there he was tuning a Dino and had just finished setting up an original GT40. Good Guy.
That's a good shout - I'd heard good things. I'll see if I can get a syncrometer sorted and improve matters first.
Cheers,
Brian
You might want to order a couple of new lambdas too, they’re a bugger to diagnose when faulty (due to being narrowband).
With the induction off, you can see if the injectors are spraying and a syncrometer and temp sensor will show if you if cylinders are firing etc - with new lambdas in the loop, you can then be sure to get it all dialled-in successfully.
With the induction off, you can see if the injectors are spraying and a syncrometer and temp sensor will show if you if cylinders are firing etc - with new lambdas in the loop, you can then be sure to get it all dialled-in successfully.
Smallish update:
I got my airflow meter and finally had a chance to improve things today. I now have the airflow balanced side to side which is a definite improvement.
I did have a play with the throttle pots and made some improvement however one of the Lamdas is still pretty unresponsive.
Next step is to replace both.
However, my question is whether I should put fresh throttle pots on? I have no idea of their age, but I’m not aware they are problematic. I don’t like the idea of randomly spending money.
I will however look to improving the throttle linkage as it’s possibly a bit worn.
Thanks,
Brian
I got my airflow meter and finally had a chance to improve things today. I now have the airflow balanced side to side which is a definite improvement.
I did have a play with the throttle pots and made some improvement however one of the Lamdas is still pretty unresponsive.
Next step is to replace both.
However, my question is whether I should put fresh throttle pots on? I have no idea of their age, but I’m not aware they are problematic. I don’t like the idea of randomly spending money.
I will however look to improving the throttle linkage as it’s possibly a bit worn.
Thanks,
Brian
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