Interpret my adaptives!
Discussion
Hi folks, I'm struggling to set my adaptives up properly and think that it may be down to the fact that the lambda are dead - anyone got any thoughts?
Interestingly, the shot below was taken towards the end of a 25 minute run, initially (the first 10 mins or so) Lambda 2 did virtually nothing sitting at about 0 - 0.1 v.
Interestingly, the shot below was taken towards the end of a 25 minute run, initially (the first 10 mins or so) Lambda 2 did virtually nothing sitting at about 0 - 0.1 v.
Edited by itiejim on Monday 22 March 19:24
Tpots and adaptives seem to be way off on each side and a lot of ignition spiking so possible a faulty tpot(s).
I would start again and work from the basics as the throttles have too great a variation between them.
1) Slacken off and remove linkrod between banks and adjust the tpots to the recommended 15% at fully closed.
2) Re-fit linkrod ensuring both pots are still showing 15%.
3) Wind idle adjust screw so tpots both read 17-18% and go from there.
You may have done this already in which case ignore it but it helped me immensely when trying to set up mine.
Im sure someone far more technical will be along to assist
I would start again and work from the basics as the throttles have too great a variation between them.
1) Slacken off and remove linkrod between banks and adjust the tpots to the recommended 15% at fully closed.
2) Re-fit linkrod ensuring both pots are still showing 15%.
3) Wind idle adjust screw so tpots both read 17-18% and go from there.
You may have done this already in which case ignore it but it helped me immensely when trying to set up mine.
Im sure someone far more technical will be along to assist
Cheers for the input, that was the way that I had tried to set them up - several times 
but I'm still struggling to get them right.
I'm just off to work in a minute so I'll try to get a trace including a bit of steady running and tickover to see if it shows the throttle spiking.
Perhaps I should just bite the bullet and get 2 new tpots and 2 new lambdas?
but I'm still struggling to get them right.I'm just off to work in a minute so I'll try to get a trace including a bit of steady running and tickover to see if it shows the throttle spiking.
Perhaps I should just bite the bullet and get 2 new tpots and 2 new lambdas?
Whoaaaa there tiger - something is massively out there for you!
I'd not carry on with it like that until you can get it to stabilise. BOTH your adaptives are maxxed out at either end.
The first and most obvious fookup is that the TPots are reading totally different values. This is your #1 problem to solve
The Lamdas 'seem' to be working OK. Lamda 2 is definitely doing somehting, lamda one perhaps has a concern, but everything is so far out it's unfair to blame the lamdas right away....
The ignition trace should be all over the shot as that is not a constant idle plot (like most people post) but a driving/load curve. As you accelerate the ignition will advance and the revs will go up etc.etc.. so you wouldn't expect it to stay flat - this is not a plot to judge spikey tpots on - you'd want steady idle for that.
From what I Can see of the TPot traces & ignition trace, where constant throttle they look pretty stable. So at the moment TPots & Lambdas aren't a great concern in themselves, but the setup certainly is!
You MUST get both TPots showing within 2% of eachother throughout the rev range - it shouldn't be difficult. You can check this with the engine off, just putting foot in more & more and comparing them after it's all setup - I'd do from scratch like skyline said.
Take bar off, slacken back, find 15% on both, reattach, Throttle stop up to 18% or so. Then sit in and pump accel, watch values, they should rise together (within 2% or so).
I'd reset your adaptives too before a restart, then try firing up - see what happens and post up.
TBH, I wouldn't drive to work like that, the banks are so unbalanced it can't be sensible - get it right fella
EDIT:
If you really have properly balanced them to be 17% or so at idle, and they are changing that much at a few % throttle then one of three things is happening.
1. TPots are foobard. I'd try changing them over from left to right and seeing if the lazy reading follows, or stays where it was. If it stays where it was then:
2. Linkrod has more slack in it the Jordan's foofaa. You'll probably need new joints on the bar
or.
3. Wiring to TPots is foobard.
The car will not be a happy bunny until you get your TPots to agree with eachother within 2% across the entire range. Also, even if they do agree nicely when engine off, they can sometimes get spiky when engine is running (pgdn 3 times from info screen to look at the dThrottle box - hopefully it says OK, but will say No Control if a TPot is spiking around.) - but seriously, you have something more fundamental than a spiky TPot there.
Wish I was nearer or I'd pop over
I'd not carry on with it like that until you can get it to stabilise. BOTH your adaptives are maxxed out at either end.
The first and most obvious fookup is that the TPots are reading totally different values. This is your #1 problem to solve
The Lamdas 'seem' to be working OK. Lamda 2 is definitely doing somehting, lamda one perhaps has a concern, but everything is so far out it's unfair to blame the lamdas right away....
The ignition trace should be all over the shot as that is not a constant idle plot (like most people post) but a driving/load curve. As you accelerate the ignition will advance and the revs will go up etc.etc.. so you wouldn't expect it to stay flat - this is not a plot to judge spikey tpots on - you'd want steady idle for that.
From what I Can see of the TPot traces & ignition trace, where constant throttle they look pretty stable. So at the moment TPots & Lambdas aren't a great concern in themselves, but the setup certainly is!
You MUST get both TPots showing within 2% of eachother throughout the rev range - it shouldn't be difficult. You can check this with the engine off, just putting foot in more & more and comparing them after it's all setup - I'd do from scratch like skyline said.
Take bar off, slacken back, find 15% on both, reattach, Throttle stop up to 18% or so. Then sit in and pump accel, watch values, they should rise together (within 2% or so).
I'd reset your adaptives too before a restart, then try firing up - see what happens and post up.
TBH, I wouldn't drive to work like that, the banks are so unbalanced it can't be sensible - get it right fella
EDIT:
If you really have properly balanced them to be 17% or so at idle, and they are changing that much at a few % throttle then one of three things is happening.
1. TPots are foobard. I'd try changing them over from left to right and seeing if the lazy reading follows, or stays where it was. If it stays where it was then:
2. Linkrod has more slack in it the Jordan's foofaa. You'll probably need new joints on the bar
or.
3. Wiring to TPots is foobard.
The car will not be a happy bunny until you get your TPots to agree with eachother within 2% across the entire range. Also, even if they do agree nicely when engine off, they can sometimes get spiky when engine is running (pgdn 3 times from info screen to look at the dThrottle box - hopefully it says OK, but will say No Control if a TPot is spiking around.) - but seriously, you have something more fundamental than a spiky TPot there.
Wish I was nearer or I'd pop over
Edited by stuthemong on Monday 22 March 21:42
Thanks folks, I'll have a play - certainly swap the lambda leads over as well, the engine has been out so it's possible that they went in wrong.
Whilst the adaptives are maxed out on tick over (or off the throttle) as soon as there's any load they are closer - albeit still too far apart. I think I'm going to get my air flow meter out and start again using "traditional" methods. Certainly sounds like a good call to renew the throttle linkage as well.
Whilst the adaptives are maxed out on tick over (or off the throttle) as soon as there's any load they are closer - albeit still too far apart. I think I'm going to get my air flow meter out and start again using "traditional" methods. Certainly sounds like a good call to renew the throttle linkage as well.
Right folks, I had a quick fiddle before driving home after nights (that's dedication).
Slackened off the link bar, with the throttle closed set the tpots to 14 then open the throttle so that they were both +/- 18 and reset the adaptives.
So - tick over was much too high - 1600 rpm or so. Off the throttle the adaptives were more or less maxed out on opposite ends of the scale, whereas with a little (or more) throttle they were more or less similar.
I got fed up with the dodgy tick over and stopped to turn the tick over down. Now, for some reason, this has made the adaptives very similar even off the throttle and better through the rev range - why???
I've posted this latest (post tick over reduction) trace below. Looks to me like on lambda is lazy (at best), whereas the other is doing what it's supposed to. I still have to try swapping the lambda leads over. Also, there is a brief period of tick over on the graph which seems to show that the throttle stops are spiking - at least from that position.
Any observations?
Anyway, off to bed...
Slackened off the link bar, with the throttle closed set the tpots to 14 then open the throttle so that they were both +/- 18 and reset the adaptives.
So - tick over was much too high - 1600 rpm or so. Off the throttle the adaptives were more or less maxed out on opposite ends of the scale, whereas with a little (or more) throttle they were more or less similar.
I got fed up with the dodgy tick over and stopped to turn the tick over down. Now, for some reason, this has made the adaptives very similar even off the throttle and better through the rev range - why???
I've posted this latest (post tick over reduction) trace below. Looks to me like on lambda is lazy (at best), whereas the other is doing what it's supposed to. I still have to try swapping the lambda leads over. Also, there is a brief period of tick over on the graph which seems to show that the throttle stops are spiking - at least from that position.
Any observations?
Anyway, off to bed...
If you want to set up the engine correct, you have to start with the mecanical set up and balance the two sides of the engine with a syncrometer. When you have both sides of the engine equal on the syncrometer you should adjust the throttlepots to the same values by losen the the screws that hold them and then turn the pots without moving the throttle linkage. If the engine is out of balance on the throttles and you set the throttle pots to show the correct values you will give the ECU incorrect values to work with.
I suggest that you download a workshop manual for the Cerbera and follow the setup instructions in the manual. In section G chapter A you will find how to do the setup.
I suggest that you download a workshop manual for the Cerbera and follow the setup instructions in the manual. In section G chapter A you will find how to do the setup.
This is what the software manual say about the lambda sensors:
After starting the sensors will take at least 30 seconds to warm up, before they will read correctly. Once warmed up, the lambda signals should switch between approx. 0 & 1-1.5 volts. 0 volts shows that the fuel mixture is lean, 1 volt shows that the mixture is rich. The rate of switching will alter with engine speed, and the percentage of time spent rich relative to lean will alter with engine load. If reading is a CONSTANT 0 V, check sensor for proper connection, and sensor heater wires for continuity (6 ohms between white red wires)
NOTE: Lambda sensors are supplied with 12V on the red wires ONLY WHEN THE FUEL PUMP IS RUNNING, the WHITE wire is earth and BLACK the signal.
On my Cerb, which is a SP6, the lambda values is on 0 volts and show spikes up to approx 1.5 volts.
After starting the sensors will take at least 30 seconds to warm up, before they will read correctly. Once warmed up, the lambda signals should switch between approx. 0 & 1-1.5 volts. 0 volts shows that the fuel mixture is lean, 1 volt shows that the mixture is rich. The rate of switching will alter with engine speed, and the percentage of time spent rich relative to lean will alter with engine load. If reading is a CONSTANT 0 V, check sensor for proper connection, and sensor heater wires for continuity (6 ohms between white red wires)
NOTE: Lambda sensors are supplied with 12V on the red wires ONLY WHEN THE FUEL PUMP IS RUNNING, the WHITE wire is earth and BLACK the signal.
On my Cerb, which is a SP6, the lambda values is on 0 volts and show spikes up to approx 1.5 volts.
One thing that would make things a little clearer would be if you could post a section of say, 3 minutes at fixed throttle, pure idle.
The lambdas look lazy to me there. On fixed idle they should bounce up&down every 2 seconds or so.
The throttle pots should not be so low to get a nice idle.
My suspicion would maybe be a leaking joint between TBodies and head/badly sealing TBodies (you rebuilt them, didn't you?). In this case a higher idle than TPot position would othwerwise indicate is maintained, as air is leaking by/around the bodies.
You then have to dial back the idle screw more than 'ideal' (&Tpot readings) to maintain the lower idle speed. In this case, more air than expected is hitting the combustion chamber so I would have expected the adaptives to be on the higher side - i.e. engine is having to add more fuel than expected from TPots reading. The only weird thing here is that your adaptives are -Ve......
Recheck your lamdas are on the right way, then maybe spray carb cleaner around the TBody/head on idle and see if revs blip?? Dunno really, seems to be more than one thing going on there for you!
The lambdas look lazy to me there. On fixed idle they should bounce up&down every 2 seconds or so.
The throttle pots should not be so low to get a nice idle.
My suspicion would maybe be a leaking joint between TBodies and head/badly sealing TBodies (you rebuilt them, didn't you?). In this case a higher idle than TPot position would othwerwise indicate is maintained, as air is leaking by/around the bodies.
You then have to dial back the idle screw more than 'ideal' (&Tpot readings) to maintain the lower idle speed. In this case, more air than expected is hitting the combustion chamber so I would have expected the adaptives to be on the higher side - i.e. engine is having to add more fuel than expected from TPots reading. The only weird thing here is that your adaptives are -Ve......
Recheck your lamdas are on the right way, then maybe spray carb cleaner around the TBody/head on idle and see if revs blip?? Dunno really, seems to be more than one thing going on there for you!
Stu, thanks for the input. I'd agree that the lambdas look lazy and am tempted to change them both. I don't think that there's much wrong with the throttle pot position as such; apparently the 4.5s need a much lower tpot reading on tick over than the 4.2s.
If I had a leak around the throttle bodies I'd expect it to be running lean and I'd never get the tick over down. Atm it sounds and smells rich and the -ve adaptives would tend to support this (I think?)It also ticks over without the butterflies totally closed so I don't think I'm far off on that, though I will check them with some carb cleaner as you suggest. I have had the lambdas out and swapped them over but had no chance to run it as yet, I'll keep you posted!
If I had a leak around the throttle bodies I'd expect it to be running lean and I'd never get the tick over down. Atm it sounds and smells rich and the -ve adaptives would tend to support this (I think?)It also ticks over without the butterflies totally closed so I don't think I'm far off on that, though I will check them with some carb cleaner as you suggest. I have had the lambdas out and swapped them over but had no chance to run it as yet, I'll keep you posted!
stuthemong said:
One thing that would make things a little clearer would be if you could post a section of say, 3 minutes at fixed throttle, pure idle.
The lambdas look lazy to me there. On fixed idle they should bounce up&down every 2 seconds or so.
The throttle pots should not be so low to get a nice idle.
My suspicion would maybe be a leaking joint between TBodies and head/badly sealing TBodies (you rebuilt them, didn't you?). In this case a higher idle than TPot position would othwerwise indicate is maintained, as air is leaking by/around the bodies.
You then have to dial back the idle screw more than 'ideal' (&Tpot readings) to maintain the lower idle speed. In this case, more air than expected is hitting the combustion chamber so I would have expected the adaptives to be on the higher side - i.e. engine is having to add more fuel than expected from TPots reading. The only weird thing here is that your adaptives are -Ve......
Recheck your lamdas are on the right way, then maybe spray carb cleaner around the TBody/head on idle and see if revs blip?? Dunno really, seems to be more than one thing going on there for you!
The lambdas look lazy to me there. On fixed idle they should bounce up&down every 2 seconds or so.
The throttle pots should not be so low to get a nice idle.
My suspicion would maybe be a leaking joint between TBodies and head/badly sealing TBodies (you rebuilt them, didn't you?). In this case a higher idle than TPot position would othwerwise indicate is maintained, as air is leaking by/around the bodies.
You then have to dial back the idle screw more than 'ideal' (&Tpot readings) to maintain the lower idle speed. In this case, more air than expected is hitting the combustion chamber so I would have expected the adaptives to be on the higher side - i.e. engine is having to add more fuel than expected from TPots reading. The only weird thing here is that your adaptives are -Ve......
Recheck your lamdas are on the right way, then maybe spray carb cleaner around the TBody/head on idle and see if revs blip?? Dunno really, seems to be more than one thing going on there for you!
if you find out, let me know. My ECU reports very low voltage too, 10.5 V ignition on, 11.5V odd idling, maybe 12V when revving >1500rpm.
Thing is, if I put a multimeter on the ECU wiring I see 12.4V ignition, and 13+V on idle, so the voltage is definitely there, just the ECU underreads it, or at least that is how it seems (maybe the ECU takes voltage off some specific pins and I have a bad earth on one of them...?). anywya, mine reads like that and runs fine, so I'm not concerned by it
Re: your main issue - point taken on 4.5 TPots, forgot the world doesn't revolve around 4.2's... does it sound fine, no missing/coughing at idle? Almost sounds as though you could have a misfire there (sending unburned fuel to lamdas to confuse) if your TPots/TBodies are good & well and you are still getting -ve adaptives... sounds to me that 2 new lamda sensors is your best port of call for now though, then see what the game is
Thing is, if I put a multimeter on the ECU wiring I see 12.4V ignition, and 13+V on idle, so the voltage is definitely there, just the ECU underreads it, or at least that is how it seems (maybe the ECU takes voltage off some specific pins and I have a bad earth on one of them...?). anywya, mine reads like that and runs fine, so I'm not concerned by it
Re: your main issue - point taken on 4.5 TPots, forgot the world doesn't revolve around 4.2's... does it sound fine, no missing/coughing at idle? Almost sounds as though you could have a misfire there (sending unburned fuel to lamdas to confuse) if your TPots/TBodies are good & well and you are still getting -ve adaptives... sounds to me that 2 new lamda sensors is your best port of call for now though, then see what the game is
Stu, it ticks over fine, no sign of a miss. I'm going to get a couple of new lambdas and see how it goes.
These look to be at a good price:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&am...
These look to be at a good price:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&am...
stuthemong said:
if you find out, let me know. My ECU reports very low voltage too, 10.5 V ignition on, 11.5V odd idling, maybe 12V when revving >1500rpm.
Low voltage at the ECU is a known problem on Cerberas. Low and noisy 12 volt too the ECU may cause different problems to engines performance. The 12 V feed to the ECU goes from the battery via a 100 amp fuse (same kind as the big fuse) that is situated above the passenger footwell to the fusebox in the back of the car. From the fusebox it then goes by the ignition control unit, the imobiliser and back to the ECU in the passenger footwell. On the way there are several connectors that can be corroded.There is a modify too cure this and get higher and more stable voltage to the ECU. What you have to do is to cut the original feed to the ECU and let that feed control a relay that takes power from the 100 amp fuse and feeds it to the ECU via a 20 amp extra fuse. I did this on my car some years ago and got smother running as a result. With the car on idle my ECU shows around 13.9-14.0 volts now, a multimeter on the alternator or the battery shows 14.4 volts. At the beginning I think it was Jools who wrote about this modification in a thread or in his Cerbera tuning manual.
itiejim said:
.... the engine has been out......
This and the values that are all over the place in your second graph makes me think about a problem I had with my car just after I bought it. When I bought the car the engine had been factory rebuilt just 50 miles ago, so I did not want too try full revs on the engine at testdrive or at the first 1500 miles after the rebuild. When I started to use higher revs the engine felt as it hit a wall at 5500 rpm´s. The software showed readings that where all over the place, as an example the ignition jumped from 45 deg to 10 deg and rpm readings where all over the place. I tried to change the crank sensor and the car worked the first time I tried 7000 rpm`s but next time the problem was back again.The problem on my car was that the guys that had mounted the engine after the rebuild had put the low voltage sensor wires together with the HT leads in the same wirestrips. The problem was solved just by moving the wires apart in the engine bay and on the engine.
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