Help - Speed Six Engine Issues
Discussion
Hi All,
Need some help diagnosing an issue with the old girl.....
Travelled all the way to South of France without an issue, and was here a while before she wouldn't start in the morning and noticed even when driving voltage was only 11.9/12.0 volts... Found an old-school English mechanic who suspected Alternator so replaced that and all seemed fine for a while.
However now I've got other type of engine issue. She starts fine, and under half-to-full throttle appears to go fine too, but anything less than half throttle and she stutters and spits and misfires... so much so that at every junction and roundabout engine stalls. To keep the engine running I have to hold it an 1500 rpm and its running very uneven and theres vibration like a misfire and a constant smell of unburnt fuel.
I've been through putting in new plugs, then a new coil pack, then new HT leads based on phone calls back to UK specialists but the problem is still there and I'm at a loss.
Finally managed to get EvoOlli's diagnostics running on a borrowed laptop... can't get the TVR diagnostiscs to run...heres some screen prints...
First use of Diagnostics after starting up...
Think some errors were when Alternator was playing up so reset them and warmed up before a run... having to hold at 1500rpm though otherwise will stall...
After a run... keep getting Crank Sensor error but no other errors logged after clearing... Turned off, Turned on again, went for another run, Crank Sensor error again..
And here's a quick snapshot of the logs.....
Today I tried to get to Lambda sensors to swap them over to see if anything changed.... but on axle stands with very few tools it is nigh on impossible.
Desperately in need of some help and advice - I need to get her back to England !!!
Thanks in advance
Mike
Need some help diagnosing an issue with the old girl.....
Travelled all the way to South of France without an issue, and was here a while before she wouldn't start in the morning and noticed even when driving voltage was only 11.9/12.0 volts... Found an old-school English mechanic who suspected Alternator so replaced that and all seemed fine for a while.
However now I've got other type of engine issue. She starts fine, and under half-to-full throttle appears to go fine too, but anything less than half throttle and she stutters and spits and misfires... so much so that at every junction and roundabout engine stalls. To keep the engine running I have to hold it an 1500 rpm and its running very uneven and theres vibration like a misfire and a constant smell of unburnt fuel.
I've been through putting in new plugs, then a new coil pack, then new HT leads based on phone calls back to UK specialists but the problem is still there and I'm at a loss.
Finally managed to get EvoOlli's diagnostics running on a borrowed laptop... can't get the TVR diagnostiscs to run...heres some screen prints...
First use of Diagnostics after starting up...
Think some errors were when Alternator was playing up so reset them and warmed up before a run... having to hold at 1500rpm though otherwise will stall...
After a run... keep getting Crank Sensor error but no other errors logged after clearing... Turned off, Turned on again, went for another run, Crank Sensor error again..
And here's a quick snapshot of the logs.....
Today I tried to get to Lambda sensors to swap them over to see if anything changed.... but on axle stands with very few tools it is nigh on impossible.
Desperately in need of some help and advice - I need to get her back to England !!!
Thanks in advance
Mike
Thanks for advice will go and see what I can check and see !!! One Problem is very few tools here 😤 certainly not got a synchronometer .. maybe the mechanic has hopefully
I’m not aware the throttle linkages have been altered by anyone... last service mechanic said they were a pig to balance after I’ve had them ‘refurbished’
I presume it’s ok to rotate the throttles using the central linkage where throttle cable attaches as can’t reach accelerator pedal when stood by the engine!!
The drags say “Lambda Control Disabled” is that correct ??
Don’t know what problem was with alternator I think the mechanic said it looked like it was just a bit worn out ???
I’ve had the air box off a few times and have been looking for anything disconnected
What should I be looking for with respect to cables ?? Could I have done something to those very thin cables that plug into the loom on the bulkhead by the air box when I’m wiggling it back in place ??? They look ok.
Thanks
I’m not aware the throttle linkages have been altered by anyone... last service mechanic said they were a pig to balance after I’ve had them ‘refurbished’
I presume it’s ok to rotate the throttles using the central linkage where throttle cable attaches as can’t reach accelerator pedal when stood by the engine!!
The drags say “Lambda Control Disabled” is that correct ??
Don’t know what problem was with alternator I think the mechanic said it looked like it was just a bit worn out ???
I’ve had the air box off a few times and have been looking for anything disconnected
What should I be looking for with respect to cables ?? Could I have done something to those very thin cables that plug into the loom on the bulkhead by the air box when I’m wiggling it back in place ??? They look ok.
Thanks
EvoOlli said:
When the ECU says: Crank Sensor problem...why don't you replace it but instead you look somewhere else ?
Shouldn't be an expensive part...after that I would look after the throttle pots...
I only found the crank sensor error after finally getting your diags to work EvoOlli... so I will order one of those just in case I can’t find a wiring problem. I’m not looking somewhere else but having changed some things TVR specialists advised me to do in absence of diags I did t want to just keep buying part after part. Thanks fir your advice..great diags by the way once I got a serial-usb cable that worked !! Shouldn't be an expensive part...after that I would look after the throttle pots...
Can't see any obvious cable issues at the moment... but need proper lighting in the garage (pretty dark even during the day with doors open) so will go get a strip light...
Hooked up diags again...
Engine not started... we have no faulty sensors and...
Throttle ... 72% / 13%
Lambda ... 0.04v / 0.03v
Adaptive .. 0.4% / 0.4%
Reset Throttles as that 72% looks seriously wrong..
Didn't change anything...
Started Engine.. and gradually increased revs a bit.... two screen grabs shown below....
No crank sensor error this time but it's a cheap part so will order one..
But... looks like Throttle Pot - Front - Blue is not happy.... Would have to be the one that's made of unobtainium wouldn;t it ? Will call Jools...
Other interesting thing... one TVR specialist told me to get a heat gun to check the temparature of all six exhausts.... to narrow down to whether it was just one cyclinder perhaps not firing for a faulty HT lead or Plug...
Cyls 123 -> 110 degrees
Cyls 456 -> 450-500 degrees
so looks like Cyls 123 are hardly firing at all ??
If I disconnect Blue throttle pot and run just on the White one would that be ok to get me back home? It's a long way and I don't want to cause any more damage that might already have been done !!
Thanks for all your help guys !
Hooked up diags again...
Engine not started... we have no faulty sensors and...
Throttle ... 72% / 13%
Lambda ... 0.04v / 0.03v
Adaptive .. 0.4% / 0.4%
Reset Throttles as that 72% looks seriously wrong..
Didn't change anything...
Started Engine.. and gradually increased revs a bit.... two screen grabs shown below....
No crank sensor error this time but it's a cheap part so will order one..
But... looks like Throttle Pot - Front - Blue is not happy.... Would have to be the one that's made of unobtainium wouldn;t it ? Will call Jools...
Other interesting thing... one TVR specialist told me to get a heat gun to check the temparature of all six exhausts.... to narrow down to whether it was just one cyclinder perhaps not firing for a faulty HT lead or Plug...
Cyls 123 -> 110 degrees
Cyls 456 -> 450-500 degrees
so looks like Cyls 123 are hardly firing at all ??
If I disconnect Blue throttle pot and run just on the White one would that be ok to get me back home? It's a long way and I don't want to cause any more damage that might already have been done !!
Thanks for all your help guys !
Thanks everyone for all your help and advice.
Will get it down to the English Mechanic out here who seems very experienced and has lots of knowledge (he says he's done lots of engine building in the past). He has a Windows XP 'snap-on tools' laptop thing with all modern OBD software etc. so hopefully we can get TVR/EvoOlli diagnostics working on that as I had to return the borrowed laptop last night.
Will throughly check all cabling and look for water ingress etc. When I removed HT leads they were bone dry and down the tubes with the spark plugs looked bone dry too (I can't remove spark plugs - no sockets long enough but he will have them)
All throttle bodies are closed with engine at idle and they all turn in unison when pressing accelerator
To get to the Lambda sensors connectors is it wheel off and battery out ?
Regards
Mike
Will get it down to the English Mechanic out here who seems very experienced and has lots of knowledge (he says he's done lots of engine building in the past). He has a Windows XP 'snap-on tools' laptop thing with all modern OBD software etc. so hopefully we can get TVR/EvoOlli diagnostics working on that as I had to return the borrowed laptop last night.
Will throughly check all cabling and look for water ingress etc. When I removed HT leads they were bone dry and down the tubes with the spark plugs looked bone dry too (I can't remove spark plugs - no sockets long enough but he will have them)
All throttle bodies are closed with engine at idle and they all turn in unison when pressing accelerator
To get to the Lambda sensors connectors is it wheel off and battery out ?
Regards
Mike
Hi All,
Yes, car is still here in France, currently at the garage with the ex-pat mechanic checking and cleaning all Ground cabling and contacts etc.
We did notice that with blue throttle pot disconnected car did drive better but it didn't 'fix' the issue on it's own, so still doing the basics with all the connections etc.
Spoke to Joolz on the phone and he's sent me a black throttle pot (blue simply no longer available. full stop.) The black one needs minor adjustment , so Joolz very kindly drilled the 7mm holes in the right place and gave me instructions to fit. It arrived today :-)
Will get that fitted and reset all error codes, adaptives etc. as per Joolz recommendation before starting engine as he says good chance the adaptives are all over the place with the way it's been running so badly in recent times and having no adaptives ins't a bad thing at the moment !
Hopefully will have some good news by the end of the week!!!
Yes, car is still here in France, currently at the garage with the ex-pat mechanic checking and cleaning all Ground cabling and contacts etc.
We did notice that with blue throttle pot disconnected car did drive better but it didn't 'fix' the issue on it's own, so still doing the basics with all the connections etc.
Spoke to Joolz on the phone and he's sent me a black throttle pot (blue simply no longer available. full stop.) The black one needs minor adjustment , so Joolz very kindly drilled the 7mm holes in the right place and gave me instructions to fit. It arrived today :-)
Will get that fitted and reset all error codes, adaptives etc. as per Joolz recommendation before starting engine as he says good chance the adaptives are all over the place with the way it's been running so badly in recent times and having no adaptives ins't a bad thing at the moment !
Hopefully will have some good news by the end of the week!!!
Hi All,
The great news is that the mis-firing engine issues appear to be fixed!!!
Gratitude and Thanks for all your support, advice, guidance etc. but especially to:
. . . Ollie - for his diagnostics that installed on my friend Windows 10 laptop
. . . Joolz (spitfirev8) - for all his help on the phone AND for supplying me with a modified black throttle pot (and fitting instructions) to replace the faulty blue one.
My ex-pat mechanic installed the new black throttle pot, cleaned the spark plugs (which were black with soot due to the issues), checked and cleaned all the possible GND connections, and she fired up, using all 6-cylinders, idled, and sounded a lot better.
Switched off, connected laptop & Ollies' S/W, reset throttles, adaptives, errors, logs... everything looked absolutely bob-on.
Started up went for a drive, and seems to be running better than ever !
Thanks guys - yet another example of what a great forum and community this can be !
Cheers
Mike
The great news is that the mis-firing engine issues appear to be fixed!!!
Gratitude and Thanks for all your support, advice, guidance etc. but especially to:
. . . Ollie - for his diagnostics that installed on my friend Windows 10 laptop
. . . Joolz (spitfirev8) - for all his help on the phone AND for supplying me with a modified black throttle pot (and fitting instructions) to replace the faulty blue one.
My ex-pat mechanic installed the new black throttle pot, cleaned the spark plugs (which were black with soot due to the issues), checked and cleaned all the possible GND connections, and she fired up, using all 6-cylinders, idled, and sounded a lot better.
Switched off, connected laptop & Ollies' S/W, reset throttles, adaptives, errors, logs... everything looked absolutely bob-on.
Started up went for a drive, and seems to be running better than ever !
Thanks guys - yet another example of what a great forum and community this can be !
Cheers
Mike
As I was advised, and can now fully testify that it's definitely true, and a major advantage to have, is the original TVR or EvoOlli's diagnostics on a Windows XP/10 laptop..... to give you some immediate clues as to whether you have a throttle pot, lambda, air-fuel ratio, crank sensor etc. issue that may help quickly diagnose the issue and maybe get a part to you (if .. if... it's a replacement part you need) ....
Where are you in France ???? I'm about 25-mins drive from Bergerac and I currently have access to the diagnostics for a couple of days more so I could potentially meet you if you are quite close to me.
Regards
Mike
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