Mapping Issue or 3rd party ECU?
Discussion
I was planning on putting some electrical tape over the actual nob, to stop it moving, once I had amended it, if it did the trick. Not long term/ideal I realise, but as I don't have a switched resistor array, I shall work with what I have. 
Also, am I being dumb? I looked at my pic again, I can just unplug the blue plug (after unplugging the ECU) and test resistance from there, can't I?
Also, am I being dumb? I looked at my pic again, I can just unplug the blue plug (after unplugging the ECU) and test resistance from there, can't I?
Monsterlime here's the data sheet for your tune resistor pot showing the pin designations:
http://www.vishay.com/docs/51036/p16pa16.pdf
If it is the same as the intermittent wiper pot it'll be a P16 103MA, where the 103 figure gives the resistance value (10 KOhms). Good luck with selecting your fuel map. Note that the ECU as part of it's software flow is regularly checking the value of the tune resistor so tweeking the pot on the fly is not a good idea.
http://www.vishay.com/docs/51036/p16pa16.pdf
If it is the same as the intermittent wiper pot it'll be a P16 103MA, where the 103 figure gives the resistance value (10 KOhms). Good luck with selecting your fuel map. Note that the ECU as part of it's software flow is regularly checking the value of the tune resistor so tweeking the pot on the fly is not a good idea.
When I changed to the Clive Y, he send as 5 position tune resistor with the pipe, but said that if the lambdas were still in it would be on the white tune resistor position....which is the same as not putting the 5 position one in at all. Which is what my guy did, and it worked fine.
I did have the "stalling when hot" issue some time after, but that turned out to be a heat sensitive stepper. BTW, some replacement steppers are less than good, and leave you with the same issue as they are simply not responding or not responding fast enough
I did have the "stalling when hot" issue some time after, but that turned out to be a heat sensitive stepper. BTW, some replacement steppers are less than good, and leave you with the same issue as they are simply not responding or not responding fast enough
The lambda's are still in, although I will triple check (with pics), hopefully tonight.
I'm on my 3rd stepper, so if it is that, it is rather frustrating. If, for example this wasn't solved by changing back to fuel map 5, where would be a good place to get a decent stepper from, or is it just a complete lottery?
All advice is very gratefully received as well.
I'm on my 3rd stepper, so if it is that, it is rather frustrating. If, for example this wasn't solved by changing back to fuel map 5, where would be a good place to get a decent stepper from, or is it just a complete lottery?
All advice is very gratefully received as well.
Edited by Monsterlime on Thursday 26th February 14:00
Monsterlime said:
The lambda's are still in, although I will triple check (with pics), hopefully tonight.
I'm on my 3rd stepper, so if it is that, it is rather frustrating. If, for example this wasn't solved by changing back to fuel map 5, where would be a good place to get a decent stepper from, or is it just a complete lottery?
All advice is very gratefully received as well.
No, your first port of call is to make sure the lambdas are still in and get back onto the white tune resistor, as already discussed. I'm on my 3rd stepper, so if it is that, it is rather frustrating. If, for example this wasn't solved by changing back to fuel map 5, where would be a good place to get a decent stepper from, or is it just a complete lottery?
All advice is very gratefully received as well.
Edited by Monsterlime on Thursday 26th February 14:00
I mentioned the stepper for two reasons:
1. There is a well documented issue with some of the spares on the market.
2. My issue with the heat sensitive stepper was a strange one. I had no hot stalling issues at all, until i changed to the Clive Y and took the pre-cats out. Then it suddenly started stalling when hot, utterly unable to hold an idle. I spent weeks trying everything anyone suggested, including getting the car hot and disconnecting the stepper. I had it totally remapped by Mark Adams ( I also has a lean running issue following an upgrade to a 5 litre V8D engine), which solved the lean running but didn't solve the stalling. In the course of that remap Mark changed the fuel pressure regulator, reset the throttle pot, created a new chip, checked the AFM and got everything absolutely spot on......but still it stalled when hot.
In the end I called Rob at V8D and he offered to have a look. I jumped in the car and drove over to see him, and it stalled several times on the way. He rechecked everything again and after an hour was at the head scratching stage. He muttered under his breath "It's got to be the stepper", so I asked him if he had a spare original TVR one off an old engine. He rootled around in the stores and found one, swapped it over and bingo....issue gone, and it has never returned in 18000 miles.
My conclusion, after weeks of trying everything, was that my original stepper, which was probably 1999 vintage, had become mechanically or electrically heat sensitive, but that sensitivity only showed after fitting the Clive Y - no idea Y. Changing the stepper for a (less worn?) different original TVR stepper solved my issue. BTW, the day after I had fitted my Clive Y I met up with another 500 owner with a newly acquired car. All he had done since acquiring it was to fit a Clive Y......and he had suddenly developed the same hot stalling issue.
So go and reset the lambdas and fuel maps/tune resistors, but just keep this in the back of your mind. If nothing else works, you are welcome to come and swap my working stepper onto your car to see if it solves it. I also have a spare stepper I got in a job lot of spares, so this weekend i will swap that onto my car to test it.....with a view to posting it to you.
QBee - Thank you very very much! That is supremely generous and hugely appreciated. Beer/Cider/Wine is definitely owed!
When I got home tonight, I disconnected the ECU, removed the blue plug and set about amending the resistance. However, I found that the particular variable resistor that is on it, only goes up to 100ohms (product code seems to be 2096A). So I removed it, and put the old one back on, using a couple of connection blocks as a temporary connection, until I solder it back on this weekend (weather permitting) and I did confirm the resistance was right before plugging it all back in.
It is definitely now using Fuel Map 5 -
That screenshot was taken only a few seconds after startup. The next was taken about 5 minutes later -
The Long Term fuel trim never moved, it stayed at 0 on both odd and even. I forgot to get a screenshot of that. Doh.
I did log a few minutes of the data and have put it here - http://pastebin.com/LZKCu1HC
The idle did seem a bit lumpier, and especially so after I rev'd it a bit, but it never seemed like it would cut out or anything and did settle down.
I have also taken some pics of the 2 Lambda sensors -
I won't have time tonight to take it for a drive, but tomorrow I can, and will also do so over the weekend (although the weather is going to be rubbish
), and see how it behaves.
Again, many thanks for the all the advice. I hope progress is being made!
When I got home tonight, I disconnected the ECU, removed the blue plug and set about amending the resistance. However, I found that the particular variable resistor that is on it, only goes up to 100ohms (product code seems to be 2096A). So I removed it, and put the old one back on, using a couple of connection blocks as a temporary connection, until I solder it back on this weekend (weather permitting) and I did confirm the resistance was right before plugging it all back in.
It is definitely now using Fuel Map 5 -
That screenshot was taken only a few seconds after startup. The next was taken about 5 minutes later -
The Long Term fuel trim never moved, it stayed at 0 on both odd and even. I forgot to get a screenshot of that. Doh.
I did log a few minutes of the data and have put it here - http://pastebin.com/LZKCu1HC
The idle did seem a bit lumpier, and especially so after I rev'd it a bit, but it never seemed like it would cut out or anything and did settle down.
I have also taken some pics of the 2 Lambda sensors -
I won't have time tonight to take it for a drive, but tomorrow I can, and will also do so over the weekend (although the weather is going to be rubbish
), and see how it behaves.Again, many thanks for the all the advice. I hope progress is being made!
I should clarify - I did let it idle for about 5 minutes before touching the accelerator. I only started logging a few minutes after it had been running, although now reading back, I possibly should have left it longer above a certain engine temp. I honestly can't say if I did that or not, I was too busy taking pics of the lambda's etc. Doh.
I shall reset it tomorrow and pay attention to what I am doing!
I shall reset it tomorrow and pay attention to what I am doing!
That second shot shows 100% short term trim on one side-but you need to have a look at the long term trim values as well- they start at zero and move slowly over a couple of minutes, however a 100% add fuel reading on short term says to me you have a dead or disconnected lambda probe. Id expect to see a 100% reading for the long term on the same bank, and possibly a lambda error code, but these take some time to show. Currently the ECU is putting lots of extra fuel in on one side, so you need to find the root cause. You could try swapping the probes over if you can get them out, and see if the 100% trim moves to the other bank.
I see, thanks. I did suspect that bit looked wrong. Some clueless questions coming -
How do I get the probes out? Are they screw in/out jobs? I've nosed through the bible and can't find any reference as to how they are removed.
Second, I did see in the bible that there are some tests you can do on the lambda's, for resistance/voltage, via the ECU plug. Are they a good place to start? There was also a dire warning about attempting them, is the plug really that fragile?
Thanks!
How do I get the probes out? Are they screw in/out jobs? I've nosed through the bible and can't find any reference as to how they are removed.
Second, I did see in the bible that there are some tests you can do on the lambda's, for resistance/voltage, via the ECU plug. Are they a good place to start? There was also a dire warning about attempting them, is the plug really that fragile?
Thanks!
They are screw out- but you cant get a ring spanner over the connector. It is possible to pull the connectors out of the plasic housing to allow you to thread with wires through the spanner by unlocking the locking tabs in the pins with a jewelers screwdriver, but its not that easy. If you cut the wires, they can be resoldered, but the wire is steel, not copper, so you need to use a plumbers flux to get the solder to take. In terms of testing, the probe should produce a switching signal of 0 to 1.2 volts depending on the mixture (black to white wires), but a 100% positive trim value means the ECU is not seeing any voltages at all, so it adds fuel trying to get the voltage to rise on the probe, but its not happening, so it hits 100%. You cant do an resistance tests Im afraid.
I have asked a friend if he has a suitable tool (I certainly don't). I did find these on Ebay - http://www.ebay.co.uk/itm/LASER-4984-Difficult-Acc... However, they explicitly exclude lambda sensors, but I can't see why.
Could a leak between the manifold and the block cause the lack of voltage? Although I would have thought it would have seen some unless it just wasn't connected at all!
Could a leak between the manifold and the block cause the lack of voltage? Although I would have thought it would have seen some unless it just wasn't connected at all!
Just my two penneth worth...
...some of you may remember I had all sorts of problems setting up my twin plenum assembly last year - my rover gauge read-out was almost identical to yours.
This winter while changing the plugs and performing the various "small service almost summer" tasks I noticed this however...
...it turns out plug number 6 having worked loose destroying my comp on that cylinder and causing a huge air leak (you can even see in the picture where the fuel was pissing out the hole). Misfires, stalling, strong smell of fuel the works. I screwed new plugs in and all was well again. Runs like a champ! Can't believe I missed this.
Check out the state of plug #6 (right) next to #4 (which is identical to all other plugs). Amazing. Can't help but feel like a right t
t.
Anyway, don't just check around the plenum for air leaks!
...some of you may remember I had all sorts of problems setting up my twin plenum assembly last year - my rover gauge read-out was almost identical to yours.
This winter while changing the plugs and performing the various "small service almost summer" tasks I noticed this however...
...it turns out plug number 6 having worked loose destroying my comp on that cylinder and causing a huge air leak (you can even see in the picture where the fuel was pissing out the hole). Misfires, stalling, strong smell of fuel the works. I screwed new plugs in and all was well again. Runs like a champ! Can't believe I missed this.
Check out the state of plug #6 (right) next to #4 (which is identical to all other plugs). Amazing. Can't help but feel like a right t
t.Anyway, don't just check around the plenum for air leaks!
Had that after a service on a brand new company car a few years ago. Right in the middle of Chelmsford there was a bang like a rifle going off and the engine sounded horrible. Pulled over and called the AA. AA man opened the bonnet, refitted the spark plug that had blown clean out, started the engine, all fine again.
Bloody main dealers.......
Bloody main dealers.......
Ok, so I have reset the ECU again, and left it running.
While it did so, I had a proper poke around the engine bay, looking for any leaks etc and I found none. I checked all the spark plugs (before I started her), and they all seemed to be in fine as well.
However, we have screenshots. These are after I restarted Rover Gauge because it had stopped changing the trim on the even Lambda, but then I realised afterwards this was because it had thrown a fault code. Before I restarted the Rover Gauge, the Short Term trim on the even Lambda was 100%, but it never registered anything on Long Term before or after. The screenshots are after about 20 minutes or so of idling, and the temp had been above 90C for around 5 minutes.
Idle Short Term -
Idle Long Term -
Fault Codes -
And finally, something rather worrying I thought. I gave it a bit of a rev after all of the above, but then this happened with the Long Term Trim -
Also! There were 2 very long black marks coming from the exhaust (before it was revved) -
So, I assume at this point, badness? Are both lambda's dodgy or is this expected when one has failed?
While it did so, I had a proper poke around the engine bay, looking for any leaks etc and I found none. I checked all the spark plugs (before I started her), and they all seemed to be in fine as well.
However, we have screenshots. These are after I restarted Rover Gauge because it had stopped changing the trim on the even Lambda, but then I realised afterwards this was because it had thrown a fault code. Before I restarted the Rover Gauge, the Short Term trim on the even Lambda was 100%, but it never registered anything on Long Term before or after. The screenshots are after about 20 minutes or so of idling, and the temp had been above 90C for around 5 minutes.
Idle Short Term -
Idle Long Term -
Fault Codes -
And finally, something rather worrying I thought. I gave it a bit of a rev after all of the above, but then this happened with the Long Term Trim -
Also! There were 2 very long black marks coming from the exhaust (before it was revved) -
So, I assume at this point, badness? Are both lambda's dodgy or is this expected when one has failed?
Another way to remove Lamdas is to get an old socket and grind a grove out the socket to allow the wires to pass through the socket then you can get socket firmly onto the nut,,, mine were very tight so the socket was essential,,,
Half inch drive and a long reach socket is the way forward as a short reach socket will foul on the lamda.
Hope that makes sense, I'd post a pic but I can't find the bleeding socket I used... Must be at work!
Half inch drive and a long reach socket is the way forward as a short reach socket will foul on the lamda.
Hope that makes sense, I'd post a pic but I can't find the bleeding socket I used... Must be at work!
I think you need to read this:
http://www.g33.co.uk/images/PDFS/14cux%20faulot%20...
It will tell you all the tricks to try to get the probes to read. I think its important to get some actual voltage readings from the back of the probes. The ECU has given up and thrown an error code as it cant get the probe to switch on even. No wonder Austec switched to the non cat Ausie map with readings like this, they are pretty contradictive. Are you seeing any cycling of the short term trim at all on either side?
http://www.g33.co.uk/images/PDFS/14cux%20faulot%20...
It will tell you all the tricks to try to get the probes to read. I think its important to get some actual voltage readings from the back of the probes. The ECU has given up and thrown an error code as it cant get the probe to switch on even. No wonder Austec switched to the non cat Ausie map with readings like this, they are pretty contradictive. Are you seeing any cycling of the short term trim at all on either side?
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