4.5 throttle linkage wear and general poor running
Discussion
Thanks for the input everyone.
Sadly Joolz's website suggests he won't actually do the fixing thereof but hopefully he can offer some insightful steer:
http://www.kitsandclassics.co.uk/servicing/
I used Aide's latest datalogging feature this morning and came back with this. I reproduced the problem - particularly on the stretch back home towards the end of the log and a few times on the way out too. Negative adaptives mean it's running lean, right? It came back with the AFRa fault code lit up red which it's never done running up the RPM unloaded in the garage. I suppose that's good - there is evidence of some sort now.
The adaptives are miles out but both negative.
It had a new fuel pressure regulator in summer. Imbalance-only issues as well as air leaks tend to manifest themselves worst at idle in my experience of other engines. Mine idles beautifully and if just driving round town you'd never know there was anything wrong with it. It's only when you put your foot down that it falls on its face. Should I try a new fuel pump?
Sadly Joolz's website suggests he won't actually do the fixing thereof but hopefully he can offer some insightful steer:
http://www.kitsandclassics.co.uk/servicing/
I used Aide's latest datalogging feature this morning and came back with this. I reproduced the problem - particularly on the stretch back home towards the end of the log and a few times on the way out too. Negative adaptives mean it's running lean, right? It came back with the AFRa fault code lit up red which it's never done running up the RPM unloaded in the garage. I suppose that's good - there is evidence of some sort now.
The adaptives are miles out but both negative.
It had a new fuel pressure regulator in summer. Imbalance-only issues as well as air leaks tend to manifest themselves worst at idle in my experience of other engines. Mine idles beautifully and if just driving round town you'd never know there was anything wrong with it. It's only when you put your foot down that it falls on its face. Should I try a new fuel pump?
As has been mentioned, I'd start from scratch, balance the throttles with an Air flow meter & make the adjustments from there.
I'd also change the lambada's as well, they are cheap enough to do just to rule them out. Also make sure they have been connected correctly, IIRC, mine were connected the wrong way around - right lambada to left bank etc.
I'd also recheck the manifolds again for cracking, it may be best to get them off to check & repair properly.
I'd also change the lambada's as well, they are cheap enough to do just to rule them out. Also make sure they have been connected correctly, IIRC, mine were connected the wrong way around - right lambada to left bank etc.
I'd also recheck the manifolds again for cracking, it may be best to get them off to check & repair properly.
jamieduff1981 said:
Thanks for the input everyone.
Sadly Joolz's website suggests he won't actually do the fixing thereof but hopefully he can offer some insightful steer:
http://www.kitsandclassics.co.uk/servicing/
I used Aide's latest datalogging feature this morning and came back with this. I reproduced the problem - particularly on the stretch back home towards the end of the log and a few times on the way out too. Negative adaptives mean it's running lean, right? It came back with the AFRa fault code lit up red which it's never done running up the RPM unloaded in the garage. I suppose that's good - there is evidence of some sort now.
The adaptives are miles out but both negative.
It had a new fuel pressure regulator in summer. Imbalance-only issues as well as air leaks tend to manifest themselves worst at idle in my experience of other engines. Mine idles beautifully and if just driving round town you'd never know there was anything wrong with it. It's only when you put your foot down that it falls on its face. Should I try a new fuel pump?
Negative adaptive values simply mean that a negative trim value is being added, i.e it's running rich.Sadly Joolz's website suggests he won't actually do the fixing thereof but hopefully he can offer some insightful steer:
http://www.kitsandclassics.co.uk/servicing/
I used Aide's latest datalogging feature this morning and came back with this. I reproduced the problem - particularly on the stretch back home towards the end of the log and a few times on the way out too. Negative adaptives mean it's running lean, right? It came back with the AFRa fault code lit up red which it's never done running up the RPM unloaded in the garage. I suppose that's good - there is evidence of some sort now.
The adaptives are miles out but both negative.
It had a new fuel pressure regulator in summer. Imbalance-only issues as well as air leaks tend to manifest themselves worst at idle in my experience of other engines. Mine idles beautifully and if just driving round town you'd never know there was anything wrong with it. It's only when you put your foot down that it falls on its face. Should I try a new fuel pump?
The ecu doesn't differentiate between rich/lean ARF faults, but I'd venture that it's a rich AFR fault in this case and while still cause for concern, not as bad as a lean (read pinking!) AFR fault.
The Min/Max pointers on the Adaptive Dial will also give you some insight.
Just to help with some of the columns on the data log, TIMEMS: Milliseconds since 01 01 1970 and, although you can't see it on the pic, speed is in Meters per second.
The thing is that Barry has spent ages chasing this problem round in circles all summer. It's psychological in some way but I'll resent the car less if I can severely punish it by stripping it apart. It needs to learn where its bread is buttered.
It runs *so* badly at wider throttle openings and it's such a drastic change that this simply cannot be slightly-off throttle set up. Throttle imbalance tends towards irrelevant the wider they're opened as the percentage difference in airflow reduces the higher the flow rates. My car runs fine until a certain throttle opening then it all just goes to pot.
I could chase this round in circles again, but the only thing that wasn't swapped was the fuel pump last time.
It runs *so* badly at wider throttle openings and it's such a drastic change that this simply cannot be slightly-off throttle set up. Throttle imbalance tends towards irrelevant the wider they're opened as the percentage difference in airflow reduces the higher the flow rates. My car runs fine until a certain throttle opening then it all just goes to pot.
I could chase this round in circles again, but the only thing that wasn't swapped was the fuel pump last time.
It hasn't had the injectors tested.
It's had new plugs, new leads, both new coils, new coolant temp. sensor, both lambdas substituted with known good ones, and both throttle pots substituted for known good ones. It has a new fuel pressure regulator also. It must have been re-set up from scratch around half a dozen times at summer chasing this issue around. TBH I don't see any benefit in repeating the exercise again without something materially having changed.
It's got to be more fundamental - like head gasket failure or something like that.
It's had new plugs, new leads, both new coils, new coolant temp. sensor, both lambdas substituted with known good ones, and both throttle pots substituted for known good ones. It has a new fuel pressure regulator also. It must have been re-set up from scratch around half a dozen times at summer chasing this issue around. TBH I don't see any benefit in repeating the exercise again without something materially having changed.
It's got to be more fundamental - like head gasket failure or something like that.
It's not RPM related. It's high throttle positions. All torque disappears and the engine just splutters. The torque then comes and goes in very short surges. It struggles to accelerate at all unless the throttles are backed off.
At light loads it runs as sweet as a nut.
Been discussing just getting rid this evening. I've had it 2 years. Year 1 was ok. Year 2 was crap. My wife won't drive it any more and I don't want to forego the things I want to do with my precious free time taking another car to bits.
At light loads it runs as sweet as a nut.
Been discussing just getting rid this evening. I've had it 2 years. Year 1 was ok. Year 2 was crap. My wife won't drive it any more and I don't want to forego the things I want to do with my precious free time taking another car to bits.
Hi Jamie,
Im sure you will have already checked this but mine did exactly the same when i got it back from a service, turns out they hadnt fully pushed on the HT leads at the rear.
This meant that it ran fine under part load, but missed and lost power at full throttle.
Hope its something simple.
Matt
Im sure you will have already checked this but mine did exactly the same when i got it back from a service, turns out they hadnt fully pushed on the HT leads at the rear.
This meant that it ran fine under part load, but missed and lost power at full throttle.
Hope its something simple.
Matt
Hi Matt,
I spoke with Joolz this morning who has counselled me to go straight to the HT side of the ignition system. My car has become steadily worse since mid 2013 where it would do this once in a blue moon until now where it does it every time. It has a set of Magnecors on which were bought in 2013 but they were hard to push on. Joolz has suggested starting with the leads and take it from there - so there would appear to be a parallel with your problem as you say.
Access is a PITA on these to get the leads on so it's not impossible it's that. I'll check that first although getting another set of leads (non-Magnecor) isn't the end of the world.
I spoke with Joolz this morning who has counselled me to go straight to the HT side of the ignition system. My car has become steadily worse since mid 2013 where it would do this once in a blue moon until now where it does it every time. It has a set of Magnecors on which were bought in 2013 but they were hard to push on. Joolz has suggested starting with the leads and take it from there - so there would appear to be a parallel with your problem as you say.
Access is a PITA on these to get the leads on so it's not impossible it's that. I'll check that first although getting another set of leads (non-Magnecor) isn't the end of the world.
jamieduff1981 said:
Hi Matt,
I spoke with Joolz this morning who has counselled me to go straight to the HT side of the ignition system. My car has become steadily worse since mid 2013 where it would do this once in a blue moon until now where it does it every time. It has a set of Magnecors on which were bought in 2013 but they were hard to push on. Joolz has suggested starting with the leads and take it from there - so there would appear to be a parallel with your problem as you say.
Access is a PITA on these to get the leads on so it's not impossible it's that. I'll check that first although getting another set of leads (non-Magnecor) isn't the end of the world.
This would be my first place to look Magnecor leads have often caused a problem and your description sounds like a weak spark which cannot cope with wider throttle openings.I spoke with Joolz this morning who has counselled me to go straight to the HT side of the ignition system. My car has become steadily worse since mid 2013 where it would do this once in a blue moon until now where it does it every time. It has a set of Magnecors on which were bought in 2013 but they were hard to push on. Joolz has suggested starting with the leads and take it from there - so there would appear to be a parallel with your problem as you say.
Access is a PITA on these to get the leads on so it's not impossible it's that. I'll check that first although getting another set of leads (non-Magnecor) isn't the end of the world.
I'm getting somewhere...
The Racetech HT leads arrived today. I removed the airboxes and inlet hoses, and noticed that I had a manifold crack on Odd/Driver Side bank. Hmm thinks I. It looks accessible from above but I thought I'd remove the manifold and get someone else to weld it.
I unplugged the lambda and they had been accidently crossed banks when plugged in to the loom. Easy to do - it's fiddly. That can't have been helping with a leaky manifold and the lambda adjusting the other bank to compensate.
I changed my mind about removing the manifold and just MIG welded the crack myself. I haven't reassembled the car yet but with the manifold and lambdas sorted and non-Magnecor HT leads I reckon it'll run miles better!
If not, I'll be crying!
The Racetech HT leads arrived today. I removed the airboxes and inlet hoses, and noticed that I had a manifold crack on Odd/Driver Side bank. Hmm thinks I. It looks accessible from above but I thought I'd remove the manifold and get someone else to weld it.
I unplugged the lambda and they had been accidently crossed banks when plugged in to the loom. Easy to do - it's fiddly. That can't have been helping with a leaky manifold and the lambda adjusting the other bank to compensate.
I changed my mind about removing the manifold and just MIG welded the crack myself. I haven't reassembled the car yet but with the manifold and lambdas sorted and non-Magnecor HT leads I reckon it'll run miles better!
If not, I'll be crying!
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