Rovergauge - no target rpm visible? and other issues
Discussion
Hi all,
yesterday I got the Rovergauge working. As the car is hard to start when hot, and the plugs are black, I wanted to know what could cause it.
In my Rovergauge screen I could see several things not ok:
- throttle position at warm idle at 12%
- idle bypass position 2 % at idle (should be 35% or so...) (no codes)
- lambda not reacting, or 100% (all green on the right)
But most curious, I am missing a target RPM figure!
No figure, and thus no green light for idle status.
ECU is from beginning of 93, so should have one.
Is there a problem so the ECU can't calculate it? Or is it more common not to have it?
Speed is 0 by the way, so it should definately be in idle and the light should be green..
I checked the stepper motor outside of the plenum, and it fully reacts. So that is not the problem causing the 2%.
I have checked the base idle, was originally 650 when fully screwed in, and with the throttle pot adjusted a little to 8%, I saw 585, so I guess I do not have vaccuum leaks.
But how can the car idle at the 850-1000 range, when there is no air leak and no idle valve opening?
Where does it get its air?
Could it be overfueling due to defective lambda's? Locked in rich mixture ? Would that raise the idle rpm?
I have not checked the advance yet, maybe the previous owner worked on that. (over 12degrees idle for instance)
Thanks for all your suggestions
yesterday I got the Rovergauge working. As the car is hard to start when hot, and the plugs are black, I wanted to know what could cause it.
In my Rovergauge screen I could see several things not ok:
- throttle position at warm idle at 12%
- idle bypass position 2 % at idle (should be 35% or so...) (no codes)
- lambda not reacting, or 100% (all green on the right)
But most curious, I am missing a target RPM figure!
No figure, and thus no green light for idle status.
ECU is from beginning of 93, so should have one.
Is there a problem so the ECU can't calculate it? Or is it more common not to have it?
Speed is 0 by the way, so it should definately be in idle and the light should be green..
I checked the stepper motor outside of the plenum, and it fully reacts. So that is not the problem causing the 2%.
I have checked the base idle, was originally 650 when fully screwed in, and with the throttle pot adjusted a little to 8%, I saw 585, so I guess I do not have vaccuum leaks.
But how can the car idle at the 850-1000 range, when there is no air leak and no idle valve opening?
Where does it get its air?
Could it be overfueling due to defective lambda's? Locked in rich mixture ? Would that raise the idle rpm?
I have not checked the advance yet, maybe the previous owner worked on that. (over 12degrees idle for instance)
Thanks for all your suggestions
I'd say the first problem to address is the 12% throttle. This is out of range for idle (it needs to be 7% or less I think, but I'll let someone else confirm that.
I don't think the order is "no target RPM therefore no idle mode light" it's "no idle mode light, therefore no target RPM". The system won't enter idle mode if the throttle is open 12%. So you should probably start by correcting that issue and then see what happens. Similarly if it's not in idle mode, then the idle bypass won't be showing the percentage you expect when it is in idle mode, if that makes sense.
I don't think the order is "no target RPM therefore no idle mode light" it's "no idle mode light, therefore no target RPM". The system won't enter idle mode if the throttle is open 12%. So you should probably start by correcting that issue and then see what happens. Similarly if it's not in idle mode, then the idle bypass won't be showing the percentage you expect when it is in idle mode, if that makes sense.
I think under 10% is still maybe a little too high.
See: http://ecumate.com/docs/Ecumate%20inst.pdf
Page 38 - actually says "typically 6%" for idle threshold. I think it uses the word 'typically' because there is some self-calibration within the 14CUX to try and cope with an ageing or slightly misadjusted throttle pot.
See: http://ecumate.com/docs/Ecumate%20inst.pdf
Page 38 - actually says "typically 6%" for idle threshold. I think it uses the word 'typically' because there is some self-calibration within the 14CUX to try and cope with an ageing or slightly misadjusted throttle pot.
ric355 said:
I think under 10% is still maybe a little too high.
See: http://ecumate.com/docs/Ecumate%20inst.pdf
Page 38 - actually says "typically 6%" for idle threshold. I think it uses the word 'typically' because there is some self-calibration within the 14CUX to try and cope with an ageing or slightly misadjusted throttle pot.
When I remove my TPS so that it springed to hard zero rovergauge read 9%. It currently reads 10% at idle and I know that my ECU is in idle mode because my TPS was at 14% and idle was uncontrolled, adjusting the TPS to 9% resulted in stable idle control. The rovergauge documentation says less than 12% and my experience proved that to be correct for me. Perhaps ecumate and rovergauge translate differently thereby displaying different readings for the same sensor positionSee: http://ecumate.com/docs/Ecumate%20inst.pdf
Page 38 - actually says "typically 6%" for idle threshold. I think it uses the word 'typically' because there is some self-calibration within the 14CUX to try and cope with an ageing or slightly misadjusted throttle pot.
Originally it was 12%, but I removed the TPS , made the holes a bit oval to be able to adjust (it is the type without slots), and adjusted it.
So maybe I need to adjust to an even lower percentage? Or is below 10% ok, not really important if it is 6 or 8?
Anyway, for the idle bypass it did not make a difference, only for the base idle (briefly below 600, so that sounds good)
Monday 2 new lambda sensors will arrive, see if that miracously solves things.
Maybe I get the idle light then, or the target rpm? (even if I do not have much hope it solves that)
So maybe I need to adjust to an even lower percentage? Or is below 10% ok, not really important if it is 6 or 8?
Anyway, for the idle bypass it did not make a difference, only for the base idle (briefly below 600, so that sounds good)
Monday 2 new lambda sensors will arrive, see if that miracously solves things.
Maybe I get the idle light then, or the target rpm? (even if I do not have much hope it solves that)
I think it's really the voltage that matters rather than the translated percentage anyway. Here's another source:
http://www.actproducts.co.uk/2011/lucas-14cux-fuel...
See the section "Throttle potentiometer" which says the voltage should be set to 0.32-0.34 volts at idle. Greater than 0.38 volts means it won't enter idle mode.
http://www.actproducts.co.uk/2011/lucas-14cux-fuel...
See the section "Throttle potentiometer" which says the voltage should be set to 0.32-0.34 volts at idle. Greater than 0.38 volts means it won't enter idle mode.
ric355 said:
I think it's really the voltage that matters rather than the translated percentage anyway. Here's another source:
http://www.actproducts.co.uk/2011/lucas-14cux-fuel...
See the section "Throttle potentiometer" which says the voltage should be set to 0.32-0.34 volts at idle. Greater than 0.38 volts means it won't enter idle mode.
I'd question whether most diy multimeters can read to that accuracy. Sure they'll give a reading but the error band could easily be larger than 0.04v which by those numbers is the difference between idle and no idlehttp://www.actproducts.co.uk/2011/lucas-14cux-fuel...
See the section "Throttle potentiometer" which says the voltage should be set to 0.32-0.34 volts at idle. Greater than 0.38 volts means it won't enter idle mode.
RobbeS said:
Hi all,
yesterday I got the Rovergauge working. As the car is hard to start when hot, and the plugs are black, I wanted to know what could cause it.
In my Rovergauge screen I could see several things not ok:
- throttle position at warm idle at 12%
- idle bypass position 2 % at idle (should be 35% or so...) (no codes)
- lambda not reacting, or 100% (all green on the right)
But most curious, I am missing a target RPM figure!
No figure, and thus no green light for idle status.
ECU is from beginning of 93, so should have one.
Is there a problem so the ECU can't calculate it? Or is it more common not to have it?
Speed is 0 by the way, so it should definately be in idle and the light should be green..
I checked the stepper motor outside of the plenum, and it fully reacts. So that is not the problem causing the 2%.
I have checked the base idle, was originally 650 when fully screwed in, and with the throttle pot adjusted a little to 8%, I saw 585, so I guess I do not have vaccuum leaks.
But how can the car idle at the 850-1000 range, when there is no air leak and no idle valve opening?
Where does it get its air?
Could it be overfueling due to defective lambda's? Locked in rich mixture ? Would that raise the idle rpm?
I have not checked the advance yet, maybe the previous owner worked on that. (over 12degrees idle for instance)
Thanks for all your suggestions
Have you checked what tune resistor you have as green is no lambda's ( No Cats )yesterday I got the Rovergauge working. As the car is hard to start when hot, and the plugs are black, I wanted to know what could cause it.
In my Rovergauge screen I could see several things not ok:
- throttle position at warm idle at 12%
- idle bypass position 2 % at idle (should be 35% or so...) (no codes)
- lambda not reacting, or 100% (all green on the right)
But most curious, I am missing a target RPM figure!
No figure, and thus no green light for idle status.
ECU is from beginning of 93, so should have one.
Is there a problem so the ECU can't calculate it? Or is it more common not to have it?
Speed is 0 by the way, so it should definately be in idle and the light should be green..
I checked the stepper motor outside of the plenum, and it fully reacts. So that is not the problem causing the 2%.
I have checked the base idle, was originally 650 when fully screwed in, and with the throttle pot adjusted a little to 8%, I saw 585, so I guess I do not have vaccuum leaks.
But how can the car idle at the 850-1000 range, when there is no air leak and no idle valve opening?
Where does it get its air?
Could it be overfueling due to defective lambda's? Locked in rich mixture ? Would that raise the idle rpm?
I have not checked the advance yet, maybe the previous owner worked on that. (over 12degrees idle for instance)
Thanks for all your suggestions
I was once told the TPS wears and the signal beomes scetchy just around the tickover point as that’s where the throttle often lives even when driving.
I know you can re configure the Ecu to read slightly higher and so move the TPS past this problem point on Mbe.
If that can be done by the likes of Joolz with CUX that sounds like a good idea as TPS are now hard to get so adjusting might solve a few people’s problems.
If the wiring is crusty old I’d have thought that would be enough to effect such a delicate reading!
I think this TPS signal issue is worth looking more closely at as a possible problem area growing due to the age of the cars and it’s wiring. It’s subjected to a lot of heat when stationary, Stone cold on the move or should be so there’s another thing to consider.
Often people tell of the car working fine until it’s hot.
I know you can re configure the Ecu to read slightly higher and so move the TPS past this problem point on Mbe.
If that can be done by the likes of Joolz with CUX that sounds like a good idea as TPS are now hard to get so adjusting might solve a few people’s problems.
If the wiring is crusty old I’d have thought that would be enough to effect such a delicate reading!
I think this TPS signal issue is worth looking more closely at as a possible problem area growing due to the age of the cars and it’s wiring. It’s subjected to a lot of heat when stationary, Stone cold on the move or should be so there’s another thing to consider.
Often people tell of the car working fine until it’s hot.
bobfather said:
I'd question whether most diy multimeters can read to that accuracy. Sure they'll give a reading but the error band could easily be larger than 0.04v which by those numbers is the difference between idle and no idle
They can. The trick in this circumstance would be to use the lowest possible range to get best accuracy. For example, read in the 0-1 volt range as millivolts, rather than using say a 0-10v range. Regardless of that though, the fact remains that there is a defined threshold and the pot needs to be set beneath it in order for idle mode to be entered - this is the point I was raising. If someone has an inaccurate meter then they're obviously going to struggle but many on here have set theirs up just fine using basic digital meters.
The lambda sensors are delayed till end of the week, so that will ahve to wait.
In the mean time I have measured the voltage of the throttle pot, and it was 0.43V. I have adjusted it to 0.33V.
This meant that I had to re-adjust the base idle, as it now ran at 400, shortly even 385 with the bypass tube pinched.
The screw was fully screwed in before, so now I was able to unscrew it almost a turn before it showed around 550.
I guess that is an improvement.
But the idle bypass position is still absurdly low, instead of 30% it is 0%...
And what do you think of my MAF readings? A little low I think.
here is a screenshot:
In the mean time I have measured the voltage of the throttle pot, and it was 0.43V. I have adjusted it to 0.33V.
This meant that I had to re-adjust the base idle, as it now ran at 400, shortly even 385 with the bypass tube pinched.
The screw was fully screwed in before, so now I was able to unscrew it almost a turn before it showed around 550.
I guess that is an improvement.
But the idle bypass position is still absurdly low, instead of 30% it is 0%...
And what do you think of my MAF readings? A little low I think.
here is a screenshot:
Any ideas on how I get I a target RPM?
Or is it a fault in the 14Cux?
I read that early ones sometimes do not show it (but still have it), but this one is dated 1993...
That said, the 5500 rpm maximum makes me think that it is not Original to my 1994 4.3 ...
And with no idle bypass, how is it possible that it idles at around 850?
When I pinch the bypass rubber hose, it absolutely lowers the rpm to the base idle at round 550...
Is it possible that the idle bypass is actually at much more than 0%, but not showing it?
If I rev it a little, the bypass % does increase and decrease again, and I have tested the thing outside the plenum, and it reacts as it is supposed to...
But I do not get it...
Or is it a fault in the 14Cux?
I read that early ones sometimes do not show it (but still have it), but this one is dated 1993...
That said, the 5500 rpm maximum makes me think that it is not Original to my 1994 4.3 ...
And with no idle bypass, how is it possible that it idles at around 850?
When I pinch the bypass rubber hose, it absolutely lowers the rpm to the base idle at round 550...
Is it possible that the idle bypass is actually at much more than 0%, but not showing it?
If I rev it a little, the bypass % does increase and decrease again, and I have tested the thing outside the plenum, and it reacts as it is supposed to...
But I do not get it...
Edited by RobbeS on Monday 4th June 18:14
RobbeS said:
When I pinch the bypass rubber hose, it absolutely lowers the rpm to the base idle at round 550...
I'd wonder whether the stepper is capable of a perfect seal, some air could get past it even when it's closed. People clean the valve plug but rarely clean the valve seat. If that is dirty you could easily see some bypass air at 0% What version of Rovergauge are you running? It's in the top left corner of the window but your image just managed to cut it off. I'm running 0.9.3.
I popped out to check behaviour;
On my car, when I start it up from cold I get an idle mode light and a target rpm. Obviously the target rpm starts to drop as the car warms up. When I press the throttle, the idle light goes out and the target rpm value gets left on the screen.
One thing of note is that my throttle position sits at 4% when off the pedal. As I increase the throttle as soon as it hits 7% the idle light goes out. i.e. on my car it has to be at 6% or less for the idle light to be on. This matches the sources I quoted earlier. You're running a different tune to me so the behaviour might be different.
The other thing I did was to leave the ignition off, put about 20% throttle on, switch on the ignition, connect roverguage, and see if it gave me a target idle even before the engine is started. This was to simulate a throttle pot that has its idle point set too high. In that circumstance it still displayed a target idle as soon as the connection was achieved, and before I started the engine.
So that all seems to suggested that either the version of software you've got doesn't show it, or it is not available from your ecu.
Incidentally do you get a better battery voltage if you give it some revs? It looks a bit low in your image. At cold idle today mine was 13.5-14v but admittedly that was at 1200 rpm due to the higher idle speed from cold.
I suspect the complete lack of any number on your screen suggests that you do in fact have an ECU that is old enough to not have the target idle available.
You can do some basic checks on your AFM using the process outlined here: http://www.g33.co.uk/pages/technical-fuel-injectio... it's a way down the page - just search for 5AM.
I don't think any of this gives any specific conclusions unfortunately.
I popped out to check behaviour;
On my car, when I start it up from cold I get an idle mode light and a target rpm. Obviously the target rpm starts to drop as the car warms up. When I press the throttle, the idle light goes out and the target rpm value gets left on the screen.
One thing of note is that my throttle position sits at 4% when off the pedal. As I increase the throttle as soon as it hits 7% the idle light goes out. i.e. on my car it has to be at 6% or less for the idle light to be on. This matches the sources I quoted earlier. You're running a different tune to me so the behaviour might be different.
The other thing I did was to leave the ignition off, put about 20% throttle on, switch on the ignition, connect roverguage, and see if it gave me a target idle even before the engine is started. This was to simulate a throttle pot that has its idle point set too high. In that circumstance it still displayed a target idle as soon as the connection was achieved, and before I started the engine.
So that all seems to suggested that either the version of software you've got doesn't show it, or it is not available from your ecu.
Incidentally do you get a better battery voltage if you give it some revs? It looks a bit low in your image. At cold idle today mine was 13.5-14v but admittedly that was at 1200 rpm due to the higher idle speed from cold.
I suspect the complete lack of any number on your screen suggests that you do in fact have an ECU that is old enough to not have the target idle available.
You can do some basic checks on your AFM using the process outlined here: http://www.g33.co.uk/pages/technical-fuel-injectio... it's a way down the page - just search for 5AM.
I don't think any of this gives any specific conclusions unfortunately.
About the version of Rovergauge, I just downloaded it, it is version 0.9.3
The voltage I have never seen above 12.7 , which indeed is low. I will check if the battery has more than that when the car idles.
I will dive into the AFM tomorrow, thanks sofar.
The voltage I have never seen above 12.7 , which indeed is low. I will check if the battery has more than that when the car idles.
I will dive into the AFM tomorrow, thanks sofar.
Edited by RobbeS on Monday 4th June 21:02
Edited by RobbeS on Monday 4th June 21:03
Edited by RobbeS on Monday 4th June 21:05
Hi Robbe,
The reason you don't have a target idle is because you have a relatively old version of code (R2422). This tune is actually about a year older than the 1993 date which I assume you are reading from the ECU housing. Older code calculated the target idle on the fly when it was needed but never stored the value in memory, so it was unavailable through the serial port.
Older code also calculated the battery voltage differently which probably accounts for the low reading, so you shouldn't worry about that.
Dan
The reason you don't have a target idle is because you have a relatively old version of code (R2422). This tune is actually about a year older than the 1993 date which I assume you are reading from the ECU housing. Older code calculated the target idle on the fly when it was needed but never stored the value in memory, so it was unavailable through the serial port.
Older code also calculated the battery voltage differently which probably accounts for the low reading, so you shouldn't worry about that.
Dan
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