New member, old cerb
Discussion
Link attached to recording of ecu diagnostic software.
Lambda 2 looks faulty, Lambda 1 was jumping around a fair bit also.
Which side do they call bank 1 or 2 on the engine, and also please give me your thoughts on the vid.
Many thanks
http://youtu.be/cdja_n6oxDc
Lambda 2 looks faulty, Lambda 1 was jumping around a fair bit also.
Which side do they call bank 1 or 2 on the engine, and also please give me your thoughts on the vid.
Many thanks
http://youtu.be/cdja_n6oxDc
Edited by scerbera on Saturday 18th October 13:58
My car eats Lambda sensors so they are now turned off in the map. I still have them in the system but when they go faulty they no longer effect the way the old girl runs. I had a problem similar to yours with a strong smell of petrol and down on power, plugged the lap top in an got that same sort of Lambda behaviour as you have suggested, except I knew it could not be the lambda's at fault this time round.
Changed the plug leads and all is now well.
Changed the plug leads and all is now well.
Left bank is one and even is driver's side so 2.
Lambda sensors are meant to 'jump' around i.e switch approx once a second between low and high readings.
The setting is done with the engine at idle. Over 3,000rpm they are out of the loop.
Difficult to say as the revs are not stable but number 2 looks to be slightly leaner than bank one. The throttle pot on the odd bank is higher than the even bank so it will be richer - giving the adaptive of -2% - which you can see from the injection time. A very slight adjustment upwards of the even throttle pot to raise the fuelling may balance it up.
Lambda sensors are meant to 'jump' around i.e switch approx once a second between low and high readings.
The setting is done with the engine at idle. Over 3,000rpm they are out of the loop.
Difficult to say as the revs are not stable but number 2 looks to be slightly leaner than bank one. The throttle pot on the odd bank is higher than the even bank so it will be richer - giving the adaptive of -2% - which you can see from the injection time. A very slight adjustment upwards of the even throttle pot to raise the fuelling may balance it up.
If you're going to fiddle, then start with the basics and make sure the throttles are set up perfectly, otherwise you spiral in to the chasing-yourself-round-in-circles loop of frustration.
Get hold of the set-up procedure and start from the beginning. When you're sure everything is set up correctly, then you can pin point faults. BTW wear in the throttle linkages can cause uneven throttle opening even if they're balanced when closed, so cast a critical eye over everything - or get the car to someone who knows AJPs inside out and get them to list anything that isn't spot-on.
Get hold of the set-up procedure and start from the beginning. When you're sure everything is set up correctly, then you can pin point faults. BTW wear in the throttle linkages can cause uneven throttle opening even if they're balanced when closed, so cast a critical eye over everything - or get the car to someone who knows AJPs inside out and get them to list anything that isn't spot-on.
On the AJP you ideally want the throttle pots to stay within 3 of each other as you open the throttle. Not sure if the 4.2 has any bearings that support the throttle spindle (the 4.5 does not), but what happens is that the as the metal supporting the spindle is worn the throttle pot then takes over as the bearing at its end of the spindle which unsurprisingly knackers it. ACT do some bearings to support the the spindle which are not that cheap, but then neither is using throttle pots as a consumable part. As has been said start with setting the throttles up properly which in summary is getting the throttle pot reading to match the physical airflow as best possible.
Good luck,
Steve
Good luck,
Steve
Not true. If the adjustment is at the maximum for additional fuel (and the limit is in the 30s just can't remember the number) and more fuel still needs to added then the lambda readings are not forced to be similar. Anyway do the full setup as suggested and it should fix your problem unless there are other problems to resolve.
Is there a full set up guide anywhere?
Assuming bank 1 and 2 are mechanically the same if I disconnect pot 2 which looks to be out then it will take pot 1 value? so the fueling will be equal for both banks. Not a solution but I should be able to hear and feel the difference. I can then go about setting them both up.
I will look at the bearing issue i can have something machined to modify if it is a common problem.
Assuming bank 1 and 2 are mechanically the same if I disconnect pot 2 which looks to be out then it will take pot 1 value? so the fueling will be equal for both banks. Not a solution but I should be able to hear and feel the difference. I can then go about setting them both up.
I will look at the bearing issue i can have something machined to modify if it is a common problem.
Have a read of this: http://www.thetvrsite.com/files/workshop-manuals/0...
scerbera said:
Is there a full set up guide anywhere?
Assuming bank 1 and 2 are mechanically the same if I disconnect pot 2 which looks to be out then it will take pot 1 value? so the fueling will be equal for both banks. Not a solution but I should be able to hear and feel the difference. I can then go about setting them both up.
I will look at the bearing issue i can have something machined to modify if it is a common problem.
Bearings are off the shelf items from ACT.Assuming bank 1 and 2 are mechanically the same if I disconnect pot 2 which looks to be out then it will take pot 1 value? so the fueling will be equal for both banks. Not a solution but I should be able to hear and feel the difference. I can then go about setting them both up.
I will look at the bearing issue i can have something machined to modify if it is a common problem.
It might be worth checking for leaks in the brake servo vacuum pipe. I had this on mine and it upsets the lambda on that side as the inlet connected to the hose will get extra air via the leak and the lambda/ECU will attempt to correct which then makes the other three cylinders run rich. This can also explain poor brake performance. Another thing I had go on mine which gave unpredictable brake performance was the non-return valve in the servo vacuum pipe.
(I sold mine a couple of weeks back but can't help drifting in here every couple of days...)
(I sold mine a couple of weeks back but can't help drifting in here every couple of days...)
grovest said:
It might be worth checking for leaks in the brake servo vacuum pipe. I had this on mine and it upsets the lambda on that side as the inlet connected to the hose will get extra air via the leak and the lambda/ECU will attempt to correct which then makes the other three cylinders run rich. This can also explain poor brake performance. Another thing I had go on mine which gave unpredictable brake performance was the non-return valve in the servo vacuum pipe.
(I sold mine a couple of weeks back but can't help drifting in here every couple of days...)
This makes sense! Before I sold it I set the throttles up and they were almost identical with adaptives hovering around +2 to -4. Both throttle pot voltages were within 1 volt up to 30%. The throttle rod ends are also brand new so little chance of play there.(I sold mine a couple of weeks back but can't help drifting in here every couple of days...)
So I don't really have time to set the throttle pots or do any investigating at the moment, but I did disconnect the throttle pot lead from the bad side. And it has made a noticeable difference, idles better, free revs with a much quicker response from idle and a touch more power id say. Also sounds better!
My cerb absolutely drinks oil, im going to rebuild during the winter if i get 5 minutes.
Has anyone ever done anything crazy like make a 4 valve head, add in vvt or anything?
My cerb absolutely drinks oil, im going to rebuild during the winter if i get 5 minutes.
Has anyone ever done anything crazy like make a 4 valve head, add in vvt or anything?
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