Can anyone help with these readings from the diag software ?
Discussion
thanks guys ....
ok car has been running perfectly up until about a week ago, pulled out of the drive onto the main road, the MIL light came on, revs kept trying to die, bunnyhopping and most definitely not a happy Cerb, so switched engine off and pushed the car back home. Aint driven the car all week since but took it out yesterday just so i could look at the problem, no MIL light but the car was running rough and misfiring .. yes there's pops and bangs but this was like a machine gun in pretty much any gear. Revs still wanted to die and it won't really idle on its own but it still accelerates fine, just as i say rather loudly and certainley not how it was a week or so ago. Got a laptop sorted with the software yesterday.
Now the car is due a service and will be going in over the next couple of weeks or so however i would like to sort this problem myself if at all possible. Believing it was a problem with one of the Lambda sensors i plugged a laptop into the ECU and took the following screen grab, now i know the readings constantly update so a grab isn't really of that much help however by the looks of it one of the throttle pots is to blame ? The minus 7.5 reading below on the right hand bank wasn't the worst as it went down to -25 ...
What do you think guys ? ... thank you as always
Steve
ok car has been running perfectly up until about a week ago, pulled out of the drive onto the main road, the MIL light came on, revs kept trying to die, bunnyhopping and most definitely not a happy Cerb, so switched engine off and pushed the car back home. Aint driven the car all week since but took it out yesterday just so i could look at the problem, no MIL light but the car was running rough and misfiring .. yes there's pops and bangs but this was like a machine gun in pretty much any gear. Revs still wanted to die and it won't really idle on its own but it still accelerates fine, just as i say rather loudly and certainley not how it was a week or so ago. Got a laptop sorted with the software yesterday.
Now the car is due a service and will be going in over the next couple of weeks or so however i would like to sort this problem myself if at all possible. Believing it was a problem with one of the Lambda sensors i plugged a laptop into the ECU and took the following screen grab, now i know the readings constantly update so a grab isn't really of that much help however by the looks of it one of the throttle pots is to blame ? The minus 7.5 reading below on the right hand bank wasn't the worst as it went down to -25 ...
What do you think guys ? ... thank you as always
Steve
Hmm, it could be the crank sensor, I thought the timing should be around 17 degrees at tickover (someone else on here should know better than me.)
The throttle pot readings are exactly the same, as though one isn't working, try disconecting one or the other to see if the engine stops, if it does its the still connected pot, as they substitute the good reading if one fails.
Don't take my word for it though, hope for a second opinion.
Sorry I cant be more helpful
The throttle pot readings are exactly the same, as though one isn't working, try disconecting one or the other to see if the engine stops, if it does its the still connected pot, as they substitute the good reading if one fails.
Don't take my word for it though, hope for a second opinion.
Sorry I cant be more helpful
the throttle pots seem correct, the adaptives are quite a ways out, especially if it went to -25. its best to use the window behind the one being displayed to get a better idea as it will give the values over time.
the one thing that stands out for me is the ignition timing... it should be around 17 which means the ecu is having to retard the timing to get the idle down, which it is not enough if its sitting at 1114.
to me, with the adaptives out (oposite ways) but the t-pots dead on and the timing 4 degrees out, the problem is the throttle balance is not set correctly between the banks and therefor effectively the t-pots are not set correctly.
if you want, next week (wed - fri) may be better for me to pop over and help you out. but if it is due for a service, if one of the valves have stretched enough to be too tight, it may not be closing and therefore causing some problems
the one thing that stands out for me is the ignition timing... it should be around 17 which means the ecu is having to retard the timing to get the idle down, which it is not enough if its sitting at 1114.
to me, with the adaptives out (oposite ways) but the t-pots dead on and the timing 4 degrees out, the problem is the throttle balance is not set correctly between the banks and therefor effectively the t-pots are not set correctly.
if you want, next week (wed - fri) may be better for me to pop over and help you out. but if it is due for a service, if one of the valves have stretched enough to be too tight, it may not be closing and therefore causing some problems
Throttle 1 is more closed than throttl 2 but its taking more fuel than 2 which is having fuel removed.
But they are only out by 1% so 1 is definitely pulling a lot more air than 2.
Have a read of the last post on this thread
It describes how Joolz at TCS does the throttle setup.
I've watched him do it a few times on my 4.2 and tried to copy what he does but it stil takes me 5 times as long
But they are only out by 1% so 1 is definitely pulling a lot more air than 2.
Have a read of the last post on this thread
It describes how Joolz at TCS does the throttle setup.
I've watched him do it a few times on my 4.2 and tried to copy what he does but it stil takes me 5 times as long
hey chaps .. thanks for this
ok .. i should have pointed out before that the above wasn't at idle .. i was having to hold those revs as the car wouldnt idle. Anyways i thought i'd have a little look round as to why it had suddenley lost the ability to idle, had a good look over the throttle linkage and noticed that the little nut holding the little screw/stopper had worked its way loose so the screw had just turned past the stop point ? .. i turned it back half a turn, tighten the nut on the other side and low and behold i get decent idle at around 1000rpm ! Took the car out this evening and it feels much better i have to say. Will plug the laptop in again tomorrow and take a fresh set of results i think.
John it would be fantastic if you could pop over next week ? .. i think im off next Thursday pretty much all day
Thanks lads
Steve
ok .. i should have pointed out before that the above wasn't at idle .. i was having to hold those revs as the car wouldnt idle. Anyways i thought i'd have a little look round as to why it had suddenley lost the ability to idle, had a good look over the throttle linkage and noticed that the little nut holding the little screw/stopper had worked its way loose so the screw had just turned past the stop point ? .. i turned it back half a turn, tighten the nut on the other side and low and behold i get decent idle at around 1000rpm ! Took the car out this evening and it feels much better i have to say. Will plug the laptop in again tomorrow and take a fresh set of results i think.
John it would be fantastic if you could pop over next week ? .. i think im off next Thursday pretty much all day
Thanks lads
Steve
Hi !
If the service on the car is made by the book, the crank sensor should be cleaned from debris every 6k. I would try to do that aswell as balancing the throttles.
Looks as the engine gets a lot more fuel than it can burn on bank 2, it could be something wrong with a sparkplug, sparkplug wire etc on that side of the engine.
// Peppe
If the service on the car is made by the book, the crank sensor should be cleaned from debris every 6k. I would try to do that aswell as balancing the throttles.
Looks as the engine gets a lot more fuel than it can burn on bank 2, it could be something wrong with a sparkplug, sparkplug wire etc on that side of the engine.
// Peppe
this car astounds me 
..
so today i decide to wash the car this afternoon ... washed by hand as always, never with my jet wash, clean and dry the car. Thought i'd see how it was running this evening, press the black button .. MIL light is flashing like a big bright flashy thing .. thought hold on a sec, this can't actually be happening so i just drove it up the lane (like 100 yards) and sure enough the car couldnt hold idle and stalled as soon as i took my foot off the gas. Clearly something is happening with water, which makes me think coils, plugs, HT leads etc .. obviously there are the other fueling/air temp issues as well.
I think my car is bonkers.
but i love it
John im probably gonna take Thursday and Friday off and i'll be around anytime you want, would be great just to have a 2nd opinion (on the 739 problems that appear to have surfaced ever since i mentioned the possibility of selling it)
.. so today i decide to wash the car this afternoon ... washed by hand as always, never with my jet wash, clean and dry the car. Thought i'd see how it was running this evening, press the black button .. MIL light is flashing like a big bright flashy thing .. thought hold on a sec, this can't actually be happening so i just drove it up the lane (like 100 yards) and sure enough the car couldnt hold idle and stalled as soon as i took my foot off the gas. Clearly something is happening with water, which makes me think coils, plugs, HT leads etc .. obviously there are the other fueling/air temp issues as well.
I think my car is bonkers.
but i love it
John im probably gonna take Thursday and Friday off and i'll be around anytime you want, would be great just to have a 2nd opinion (on the 739 problems that appear to have surfaced ever since i mentioned the possibility of selling it
) Brooksie said:
this car astounds me ..
so today i decide to wash the car this afternoon ... washed by hand as always, never with my jet wash, clean and dry the car. Thought i'd see how it was running this evening, press the black button .. MIL light is flashing like a big bright flashy thing .. thought hold on a sec, this can't actually be happening so i just drove it up the lane (like 100 yards) and sure enough the car couldnt hold idle and stalled as soon as i took my foot off the gas. Clearly something is happening with water, which makes me think coils, plugs, HT leads etc .. obviously there are the other fueling/air temp issues as well.
I think my car is bonkers.
but i love it
John im probably gonna take Thursday and Friday off and i'll be around anytime you want, would be great just to have a 2nd opinion (on the 739 problems that appear to have surfaced ever since i mentioned the possibility of selling it)
.. so today i decide to wash the car this afternoon ... washed by hand as always, never with my jet wash, clean and dry the car. Thought i'd see how it was running this evening, press the black button .. MIL light is flashing like a big bright flashy thing .. thought hold on a sec, this can't actually be happening so i just drove it up the lane (like 100 yards) and sure enough the car couldnt hold idle and stalled as soon as i took my foot off the gas. Clearly something is happening with water, which makes me think coils, plugs, HT leads etc .. obviously there are the other fueling/air temp issues as well.
I think my car is bonkers.
but i love it
John im probably gonna take Thursday and Friday off and i'll be around anytime you want, would be great just to have a 2nd opinion (on the 739 problems that appear to have surfaced ever since i mentioned the possibility of selling it
) If it won't hold idle and you want to have a look at the diagnostics without having to sit there with your foot on the gas, then pop the idle screw up a couple of turns to the left. This will let the car idle from cold. It will also mean that you can drive it without stalling until the car warms up. The only downside is that as the car warms up the idle will increase to around 1500-1600, but if you're going to tinker with it on Thurs and Fri it shouldn't be too much of a problem...
MB
Just wanted to update this thread in case others have similar problems .. HUGE thanks to John (Methodwares) for coming round and helping out (well .. actually doing everything whilst i just stood there looking clueless ) .. Problem was traced to a faulty throttle pos sensor, ordered one today from TVR power. In the meantime John set the idle and adjusted the throttle pots and the car now purrrs .. well rumbles, doesn't back fire and sounds as lovely as a lovely thing again.
) .. Problem was traced to a faulty throttle pos sensor, ordered one today from TVR power. In the meantime John set the idle and adjusted the throttle pots and the car now purrrs .. well rumbles, doesn't back fire and sounds as lovely as a lovely thing again. 
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