Your opinion please - ECU Diag data
Discussion
Finally getting my Cerbera back up and running (just in time for Winter).
It's running a bit rough, idle is all over the place and needs a few revs to pull away (once warmed up). Also runs quite poorly on constant throttle between 2-3k rpm.
Now I know the linkage has a bit of play in it, for which I'm going to get some rose joints this week.
I've also changed lambda 2 yesterday as it wasn't reading anything at all.
It seems to me from this diag data that the TPS on the drivers side is up the swanny?
It's running a bit rough, idle is all over the place and needs a few revs to pull away (once warmed up). Also runs quite poorly on constant throttle between 2-3k rpm.
Now I know the linkage has a bit of play in it, for which I'm going to get some rose joints this week.
I've also changed lambda 2 yesterday as it wasn't reading anything at all.
It seems to me from this diag data that the TPS on the drivers side is up the swanny?
I agree, the setup looks very poor so fix that first. I am just about to rebuild my linkage to get rid of an error of less than 8% between the banks. Also I would have thought a bad throttle pot would give a signal with more obvious square edged spikes and you don't have any of those.
I happened to have a spare TP, so I've just switched it over. It doesn't seem to be quite so jumpy, but it still isn't brilliant.
I've also set up the throttle linkage so the throttles are a bit more balanced and the idle is just over 1k rpm.
Could slop in the linkage really give the readings on TPot 2 that I'm seeing? They're quite big jumps at times.
PMessling: Where did you get your rose joints from? What thread are they, M6?
I've also set up the throttle linkage so the throttles are a bit more balanced and the idle is just over 1k rpm.
Could slop in the linkage really give the readings on TPot 2 that I'm seeing? They're quite big jumps at times.
PMessling: Where did you get your rose joints from? What thread are they, M6?
You need to follow the procedure in the manual and read the notes from mikesr here http://www.pistonheads.com/gassing/topic.asp?h=0&a...
The TPs and lambdas have to be equal (TPs within 1%) at tickover and then when you depress the throttle they should climb together. Because of the way the linkages work a very small amount of slop will give a big error and mean that you will be effectively driving on one bank when you are pootling around town.
The TPs and lambdas have to be equal (TPs within 1%) at tickover and then when you depress the throttle they should climb together. Because of the way the linkages work a very small amount of slop will give a big error and mean that you will be effectively driving on one bank when you are pootling around town.
I may be wrong but believe If the mechanical linkage is good you can disconnect a throttle pot completely and the MBE ECU will automatically substitute the value of the good pot into the missing TP meaning that each back will get equal fuelling.
I run an emerald ECU and that only has 1 TP and it runs and ticks over far better than the MBE. 2 TP very seldom track together you can set them at tick over to be equal but then when you press the throttle they will very rarely track each other to within 2 or 3% over the whole range.
I run an emerald ECU and that only has 1 TP and it runs and ticks over far better than the MBE. 2 TP very seldom track together you can set them at tick over to be equal but then when you press the throttle they will very rarely track each other to within 2 or 3% over the whole range.
Found your old topic pmessling: http://www.pistonheads.com/gassing/topic.asp?t=105...
I'd definitely be interested in one.
Going to see how the car runs with my adjustments tomorrow. Also get the rose joints on order. If it's still a bit lumpy I might try running with one TP.
I'd definitely be interested in one.
Going to see how the car runs with my adjustments tomorrow. Also get the rose joints on order. If it's still a bit lumpy I might try running with one TP.
Edited by jammy_basturd on Sunday 10th November 22:21
Fitted the rose joints today. Decided to start from scratch with setting up the throttles, so whipped out the engine manual. Took the air boxes off, took the linkage off, made sure the throttles were closed. Then set up the Tpots to read 14.8 on both. Fitted the linkage, still reading 14.8. Increased the idle screw so the Tpots were now reading just over 20.
Fired her up. Running sweeter now, but just won't idle. She'll idle high (1800 rpm ish) for about 10 seconds, then just die. Got a screenshot of the diag graph:
I had to cut off a small part of the linkage bar to fit it without opening one of the throttles slightly. Not sure why it won't idle though?
Fired her up. Running sweeter now, but just won't idle. She'll idle high (1800 rpm ish) for about 10 seconds, then just die. Got a screenshot of the diag graph:
I had to cut off a small part of the linkage bar to fit it without opening one of the throttles slightly. Not sure why it won't idle though?
Looking at the data readings, the engine revs are 1483rpm but the battery voltage is 12.3v so the alternator is not charging. At that speed it should be charging.
The throttle pots are identical at 22.9.
I just fitted 2 new pots without the diagnostic software (haven't got round to it yet) and fitted each one at the centre of travel either left or right. Started her up and after a very short time she died. Even warming her up made no difference, cutting out every time.
So, I slackened the fixing screws and rotated both anticlockwise (viewed from the front) to a point between the middle and fully turned to the left. Started her up and she idles very evenly at an indicated 1,100. The alternator is also charging at this speed.
This will do for a base setting until I can do the diagnostic.
Might be worth checking the wiring and the 100 amp fuse for any corrosion too.
The throttle pots are identical at 22.9.
I just fitted 2 new pots without the diagnostic software (haven't got round to it yet) and fitted each one at the centre of travel either left or right. Started her up and after a very short time she died. Even warming her up made no difference, cutting out every time.
So, I slackened the fixing screws and rotated both anticlockwise (viewed from the front) to a point between the middle and fully turned to the left. Started her up and she idles very evenly at an indicated 1,100. The alternator is also charging at this speed.
This will do for a base setting until I can do the diagnostic.
Might be worth checking the wiring and the 100 amp fuse for any corrosion too.
I had running issues due to current issues, flat spots, rough running.
Was the big fuse and supply wiring, high lighted by 11.9 volts on the diagonstic. This helped running loads.
Found the exposed terminals on the fuel pump were corroded, repaired them and renewed a length of cable too. Results flat spot gone and woosh!
Lesson learnt, start with the basics rule out electrics, fuel pressure, air leaks. These are easy to check.
Was the big fuse and supply wiring, high lighted by 11.9 volts on the diagonstic. This helped running loads.
Found the exposed terminals on the fuel pump were corroded, repaired them and renewed a length of cable too. Results flat spot gone and woosh!
Lesson learnt, start with the basics rule out electrics, fuel pressure, air leaks. These are easy to check.
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