Poor Idle / Rovergauge Help
Discussion
All looks good to me. I'd leave the stepper well alone. The high idle coming to rest 'problem' is probably due to the infamous TVR road speed signal unit.
Note that the ECU doesn't know what the base idle setting on the plenum is; when calculating target RPM in Idle Mode the ECU uses a base idle value set in the PROM, which for TVR 4.0 Cat tunes is 850.
How did you set the plenum base idle so accurately at 500 RPM without stalling?
Note that the ECU doesn't know what the base idle setting on the plenum is; when calculating target RPM in Idle Mode the ECU uses a base idle value set in the PROM, which for TVR 4.0 Cat tunes is 850.
How did you set the plenum base idle so accurately at 500 RPM without stalling?
blitzracing said:
there are some interesting remaps by Steve Sprint downloadable FOC. Nice touches like latest Lucas code, (called operation pride) that irons out some bugs, and improved RPM boundary's and extended RPM mapping.
http://home2.btconnect.com/stevesprint/remap-14cux...
The files are .bin files (ie basic binary) and just need copying into a 27C256 Eprom.
Woah! Good find there!http://home2.btconnect.com/stevesprint/remap-14cux...
The files are .bin files (ie basic binary) and just need copying into a 27C256 Eprom.
CHIMV8 500 said:
Interesting this topic
I have a very similar issue,runs fine but idle is suspect and also has the tendency of cutting out when stationery,but starts straight away with no issue
Fuel smell is also present especially the longer the engine is turning over
Had her booked in with Jools to sort but unfortunately I bust 2 disks in my back and had to cancel??????
Jools if you read this, im now waiting for back operation.I have a very similar issue,runs fine but idle is suspect and also has the tendency of cutting out when stationery,but starts straight away with no issue
Fuel smell is also present especially the longer the engine is turning over
Had her booked in with Jools to sort but unfortunately I bust 2 disks in my back and had to cancel??????
Edited by CHIMV8 500 on Saturday 29th April 13:04
Ok as stated above Jools was going to sort this but,in the meantime thought id have a tinker with it and get Peter Jackson round.
In bullit point description we did
Checked set up of TPS and adjusted to correct reading
Checked AFM and checked within tolerance
Changed the stepper motor,and checked was working
Run engine and disconnected stepper at decent idle,and she seemed to run fine,then reconnected stepper,stalled after 15 seconds
Checked all pipes/seals correct
Ensured all up to temperature and correct reading on Rover Gauge and dashboard
This is what showed on the Rover Gauge
Funny thing is the Lambda readings moved to the right after approx 15 seconds from ignition at exactly the same rate to the end
The engine was flutuating up and down at this point,when reved the Lambda readings returned to dead centre,then when idling returned to the right
We decided to remove left hand lambda sensor(Pete wanted my forearm to look like Nikki Laudas ear lobe!!) to see outcome.
Engine on,after 15 seconds both left and right reading moved to the right and stayed there????
Put the left sensor back in and removed the right
This is what happended for approx 5 minutes with perfect idle
Decided to turn engine off and restart still with righthand sensor diconnected
Back to this
Think i caught the revs on the down when i took this photos oops
We decided something is weird and need you guys to comment please
Edited by CHIMV8 500 on Wednesday 14th June 13:33
Use the Rovergauge logging facility for this- you need to measure AFM, RPM, Lambda short term trim, and Stepper position. The two sides of the lambda trim don't make sense- if you disconnect one probe you should get 100% add fuel trim on that side, and the other side should keep cycling. It can be difficult to pin down an issue like this, but certainly and AFM voltage going high(when they get hot) will over fuel the engine and cause it to die- but it may be difficult to catch in the logs due to the lambda trim trying to correct for the fault. I had just this issue, but was running the green map with an AFR gauge, so I could see the mixture become highly rich as the AFM output went up before the car died. A replacement AFM has fixed the issue.
blitzracing said:
Use the Rovergauge logging facility for this- you need to measure AFM, RPM, Lambda short term trim, and Stepper position. The two sides of the lambda trim don't make sense- if you disconnect one probe you should get 100% add fuel trim on that side, and the other side should keep cycling. It can be difficult to pin down an issue like this, but certainly and AFM voltage going high(when they get hot) will over fuel the engine and cause it to die- but it may be difficult to catch in the logs due to the lambda trim trying to correct for the fault. I had just this issue, but was running the green map with an AFR gauge, so I could see the mixture become highly rich as the AFM output went up before the car died. A replacement AFM has fixed the issue.
Questionis why when the sensors are disconnected do the readings not drop off?blitzracing said:
Use the Rovergauge logging facility for this- you need to measure AFM, RPM, Lambda short term trim, and Stepper position. The two sides of the lambda trim don't make sense- if you disconnect one probe you should get 100% add fuel trim on that side, and the other side should keep cycling. It can be difficult to pin down an issue like this, but certainly and AFM voltage going high(when they get hot) will over fuel the engine and cause it to die- but it may be difficult to catch in the logs due to the lambda trim trying to correct for the fault. I had just this issue, but was running the green map with an AFR gauge, so I could see the mixture become highly rich as the AFM output went up before the car died. A replacement AFM has fixed the issue.
MarkLogs emailed to you just now
Think i have done it correct
Just to confirm Pete and i swopped the AFM over,one of them was from Petes car which we know from his car was fine
Edited by CHIMV8 500 on Saturday 17th June 13:15
Had a look at the logs- you have loads of time when the trim is at max at 255 adding fuel ( Last 2 columns ) and it looks like when you are driving as well, but it could just be the long trim is still out as you have done an ECU reset. Adding fuel is likely to be either too much air (air leak) , low fuel pressure or a bad misfire.
58:11.7 37 19 77 93 24 0.0715037 0.0656449 0.138889 13.77 5 1 9 700 255 255
58:12.2 38 1932 93 24 0.0715037 0.0646038 0.138889 13.77 5 1 9 700 255 255
58:12.6 38 1863 93 24 0.0715037 0.0629844 0.138889 13.77 5 1 8 700 255 255
58:13.0 37 1794 93 24 0.0725552 0.0629844 0.138889 13.77 5 1 8 700 255 255
58:13.3 37 1735 93 24 0.0799159 0.0651822 0.138889 13.77 5 1 8 700 255 255
58:13.8 37 1739 93 24 0.0872765 0.0674378 0.138889 13.77 5 1 8 700 255 255
58:14.1 37 1680 93 24 0.121977 0.0837478 0.161111 13.77 5 2 8 700 255 255
58:14.5 37 1697 93 24 0.13775 0.0965876 0.183333 13.77 5 2 8 700 255 255
58:14.8 37 1725 93 24 0.161935 0.125622 0.183333 13.77 5 3 8 700 255 255
58:15.3 37 1780 93 24 0.180862 0.144072 0.183333 13.77 5 3 8 700 255 255
58:15.6 37 1890 93 24 0.211356 0.178195 0.183333 13.77 5 4 9 700 255 255
58:16.1 37 1975 93 24 0.229232 0.198959 0.183333 13.77 5 4 9 700 255 255
58:16.3 37 2139 93 24 0.223975 0.20561 0.183333 13.77 5 3 9 700 255 255
58:16.8 37 2177 93 24 0.168244 0.15882 0.183333 13.77 5 2 9 700 255 255
58:17.1 37 2215 93 24 0.165089 0.13823 0.183333 13.77 5 2 9 700 255 255
58:17.6 37 2243 93 24 0.161935 0.13395 0.183333 13.77 5 2 9 700 255 255
58:17.9 37 2256 93 24 0.160883 0.132736 0.183333 13.77 5 2 9 700 255 255
58:18.3 37 2259 93 24 0.160883 0.131695 0.183333 13.77 5 2 9 700 255 255
58:18.6 37 2265 93 24 0.160883 0.13395 0.183333 13.77 5 2 9 700 255 255
58:19.1 37 2273 93 24 0.159832 0.133083 0.183333 13.77 5 2 10 700 255 255
58:19.4 37 2299 93 24 0.159832 0.131695 0.183333 13.77 5 2 10 700 255 255
58:19.9 38 2318 93 24 0.179811 0.144939 0.183333 13.77 5 2 10 700 255 255
58:20.1 38 2395 93 24 0.236593 0.217293 0.183333 13.77 5 3 10 700 255 255
58:20.6 37 2491 93 24 0.25552 0.242337 0.183333 13.77 5 4 10 700 255 255
58:20.9 37 2630 93 24 0.262881 0.261943 0.183333 13.77 5 4 10 700 255 255
58:21.4 38 2698 93 24 0.262881 0.265414 0.183333 13.77 5 3 10 700 193 255
58:21.7 38 2810 93 24 0.231335 0.227415 0.183333 13.77 5 2 10 700 255 255
58:22.1 37 2832 93 24 0.206099 0.194274 0.183333 13.77 5 2 10 700 255 255
58:11.7 37 19 77 93 24 0.0715037 0.0656449 0.138889 13.77 5 1 9 700 255 255
58:12.2 38 1932 93 24 0.0715037 0.0646038 0.138889 13.77 5 1 9 700 255 255
58:12.6 38 1863 93 24 0.0715037 0.0629844 0.138889 13.77 5 1 8 700 255 255
58:13.0 37 1794 93 24 0.0725552 0.0629844 0.138889 13.77 5 1 8 700 255 255
58:13.3 37 1735 93 24 0.0799159 0.0651822 0.138889 13.77 5 1 8 700 255 255
58:13.8 37 1739 93 24 0.0872765 0.0674378 0.138889 13.77 5 1 8 700 255 255
58:14.1 37 1680 93 24 0.121977 0.0837478 0.161111 13.77 5 2 8 700 255 255
58:14.5 37 1697 93 24 0.13775 0.0965876 0.183333 13.77 5 2 8 700 255 255
58:14.8 37 1725 93 24 0.161935 0.125622 0.183333 13.77 5 3 8 700 255 255
58:15.3 37 1780 93 24 0.180862 0.144072 0.183333 13.77 5 3 8 700 255 255
58:15.6 37 1890 93 24 0.211356 0.178195 0.183333 13.77 5 4 9 700 255 255
58:16.1 37 1975 93 24 0.229232 0.198959 0.183333 13.77 5 4 9 700 255 255
58:16.3 37 2139 93 24 0.223975 0.20561 0.183333 13.77 5 3 9 700 255 255
58:16.8 37 2177 93 24 0.168244 0.15882 0.183333 13.77 5 2 9 700 255 255
58:17.1 37 2215 93 24 0.165089 0.13823 0.183333 13.77 5 2 9 700 255 255
58:17.6 37 2243 93 24 0.161935 0.13395 0.183333 13.77 5 2 9 700 255 255
58:17.9 37 2256 93 24 0.160883 0.132736 0.183333 13.77 5 2 9 700 255 255
58:18.3 37 2259 93 24 0.160883 0.131695 0.183333 13.77 5 2 9 700 255 255
58:18.6 37 2265 93 24 0.160883 0.13395 0.183333 13.77 5 2 9 700 255 255
58:19.1 37 2273 93 24 0.159832 0.133083 0.183333 13.77 5 2 10 700 255 255
58:19.4 37 2299 93 24 0.159832 0.131695 0.183333 13.77 5 2 10 700 255 255
58:19.9 38 2318 93 24 0.179811 0.144939 0.183333 13.77 5 2 10 700 255 255
58:20.1 38 2395 93 24 0.236593 0.217293 0.183333 13.77 5 3 10 700 255 255
58:20.6 37 2491 93 24 0.25552 0.242337 0.183333 13.77 5 4 10 700 255 255
58:20.9 37 2630 93 24 0.262881 0.261943 0.183333 13.77 5 4 10 700 255 255
58:21.4 38 2698 93 24 0.262881 0.265414 0.183333 13.77 5 3 10 700 193 255
58:21.7 38 2810 93 24 0.231335 0.227415 0.183333 13.77 5 2 10 700 255 255
58:22.1 37 2832 93 24 0.206099 0.194274 0.183333 13.77 5 2 10 700 255 255
Edited by blitzracing on Sunday 18th June 16:30
Edited by blitzracing on Sunday 18th June 16:33
Hi from nz .
I have a newly rebuilt 4.2 running in a two door range rover.
My issue is in order to achieve a positive idle air control value,i have to turn down the idle bypass to near the stop.
This restricts air on start up and causes stall or hard starting.
If i open the bypass 1.5 turns i get consistent idle and smooth off load idle .
My dilemma is on cold start the stepper resets perfectly to 100%,on warm restarts it only goes to 17% as seen by rovergauge.
If i pull the connecting plug and check the physical position,it is actually fully retracted so should show 100.
Subsequent readings at warm idle drop the idle control value to 0% from that initial 17%.
Then after a week or so it throws the stepper code,as the program now see's this as out of range.
It has done this on two engines.
I have 20x times checked for air leaks ,all hoses free and no leaks.
Reused the same plenum with the 3.9 now the 4.2 .
I see the throtttle position percentage is a little high but not unduly so,at 6-7%.
Apart from this the vehicle runs fine,bugs me that rovergauge shows the stepper position is no where near mid range,in fact off scale usually unless reved up..
Changed stepper motors with an original ac delco,that replaced an original,and same deal.
Aware that some aftermarket ones have too long a pintle but an added washer brings them back in line,and the previous chinese copy used to work well till i broke it.
The steppers are clean and lubed.
Whats goin on?,any help greatly appreciated cheers Westy
I have a newly rebuilt 4.2 running in a two door range rover.
My issue is in order to achieve a positive idle air control value,i have to turn down the idle bypass to near the stop.
This restricts air on start up and causes stall or hard starting.
If i open the bypass 1.5 turns i get consistent idle and smooth off load idle .
My dilemma is on cold start the stepper resets perfectly to 100%,on warm restarts it only goes to 17% as seen by rovergauge.
If i pull the connecting plug and check the physical position,it is actually fully retracted so should show 100.
Subsequent readings at warm idle drop the idle control value to 0% from that initial 17%.
Then after a week or so it throws the stepper code,as the program now see's this as out of range.
It has done this on two engines.
I have 20x times checked for air leaks ,all hoses free and no leaks.
Reused the same plenum with the 3.9 now the 4.2 .
I see the throtttle position percentage is a little high but not unduly so,at 6-7%.
Apart from this the vehicle runs fine,bugs me that rovergauge shows the stepper position is no where near mid range,in fact off scale usually unless reved up..
Changed stepper motors with an original ac delco,that replaced an original,and same deal.
Aware that some aftermarket ones have too long a pintle but an added washer brings them back in line,and the previous chinese copy used to work well till i broke it.
The steppers are clean and lubed.
Whats goin on?,any help greatly appreciated cheers Westy
What is your idle with the stepper feed blocked off? Quite simply the air bypass screw fully tightened down should shut most of the air of and the engine wont run until you screw it up a few turns. There should be a tiny gap you set with a feeler gauge around the edge of the throttle plate, but if this is wrong, you will get extra air. Your stepper value is too low at warm idle- typically its around 30%, so air is getting in somewhere, especially if its throwing a stepper out of range error. Can you get sensible shifts in RPM if you use RoverGauge to move the stepper? 30 steps is a good place to start. The ECU has no way of telling where the stepper is as there is no feedback, so it starts at fully open, and simply counts how many steps its applied and reports back it should be where ever. You could also do small shifts with rovergauge with the stepper in your hand to make sure it responds as expected, but don't forget it will ping apart of you exceed the fully closed limit, and the cone and spring pop out, so do it in a tray so nothing gets lost.
Just had a closer look at the picture- the RPM is still 770 rpm when it should be 700 rpm , with the stepper pretty much fully shut, so air is getting in somewhere it should not be. Try closing the stepper fully, disconnecting it, and then blow into the air feed pipe that feeds the stepper to make sure there is no airflow.
Just had a closer look at the picture- the RPM is still 770 rpm when it should be 700 rpm , with the stepper pretty much fully shut, so air is getting in somewhere it should not be. Try closing the stepper fully, disconnecting it, and then blow into the air feed pipe that feeds the stepper to make sure there is no airflow.
Edited by blitzracing on Wednesday 6th December 21:14
Gidday Mark,Ta for the response.
The common component on both recent engine builds has to be the plenum.
I will definitely check the throttle gap,but assumed if rovergauge see's 6% at idle it wouldn't be far off,and tps is working in range .33volts.
On first start and month after the 4.2 build,i got 12% stable,then a distributor and injector change has it back near zero,,,maybe coincidence.
A little background is that the efi plenum is running a vacuum line from a plenum port to the original diff lock for the lt95 gearbox.I checked the vacuum and seems ok with a suck blow test but it's 40 years old so may be the actuating diaphragm has a slow leak enough to affect the iac closing off.
Will carry out the tests and come back to you,the weird one is the warm restart sets the iac % to 17 consistently.Cycling the igniton on off a couple of times,takes it up to 33% and left to cool down shows 100% as it should.
Ps;that snapshot with 770 rpm was taken after rovergauge had been disconnected but the idle does normally come back to 700 nicely.
The common component on both recent engine builds has to be the plenum.
I will definitely check the throttle gap,but assumed if rovergauge see's 6% at idle it wouldn't be far off,and tps is working in range .33volts.
On first start and month after the 4.2 build,i got 12% stable,then a distributor and injector change has it back near zero,,,maybe coincidence.
A little background is that the efi plenum is running a vacuum line from a plenum port to the original diff lock for the lt95 gearbox.I checked the vacuum and seems ok with a suck blow test but it's 40 years old so may be the actuating diaphragm has a slow leak enough to affect the iac closing off.
Will carry out the tests and come back to you,the weird one is the warm restart sets the iac % to 17 consistently.Cycling the igniton on off a couple of times,takes it up to 33% and left to cool down shows 100% as it should.
Ps;that snapshot with 770 rpm was taken after rovergauge had been disconnected but the idle does normally come back to 700 nicely.
Checked the iac closed off and blew thru hose,seems to be a good block there.
Trialling open/closing valve off the car seems to be bit random.
Ignition on and commanding movement doesn't get a response.
Start car ,reset and try again with success.
Could this possibly be a intermittent wire break that only manifests itself when hot?
Normal op sees the valve set at 100% prior start then come back to 30 then dribble back to 0-2%
[/quote]
Trialling open/closing valve off the car seems to be bit random.
Ignition on and commanding movement doesn't get a response.
Start car ,reset and try again with success.
Could this possibly be a intermittent wire break that only manifests itself when hot?
Normal op sees the valve set at 100% prior start then come back to 30 then dribble back to 0-2%
[/quote]
Rewired new leads to a new plug for the idle air stepper motor from near the ecu suspecting intermittent potential break in loom.
I get consistent iac return to 100% for the first few starts from cold,so all good.
Once engine has warmed it will not return to 100% every time.
Is this a fuction of the 14cux that it knows it doesn't need fully open on a warm engine perhaps,so counts less steps of the valve for warm starts?
It also doesn't flare on warm start as per cold and settles quickly to 700 ish.
Changed plenum also and no air leaks.
TPS working set at 33.rss seems fine.
I can achieve10- 13% on idle position by removing washer from iac,and fine tuning base idle.
At least it's now in range and not throwing stepper code,,any one had a similar experience?ta westy
I get consistent iac return to 100% for the first few starts from cold,so all good.
Once engine has warmed it will not return to 100% every time.
Is this a fuction of the 14cux that it knows it doesn't need fully open on a warm engine perhaps,so counts less steps of the valve for warm starts?
It also doesn't flare on warm start as per cold and settles quickly to 700 ish.
Changed plenum also and no air leaks.
TPS working set at 33.rss seems fine.
I can achieve10- 13% on idle position by removing washer from iac,and fine tuning base idle.
At least it's now in range and not throwing stepper code,,any one had a similar experience?ta westy
Air leak. Removed intake manifold and redid sealed ends and some high temp around air intake ports.
Heads were barely skimmed but guessing the faces weren't quite flat mating so there's the air leak.
Although not fully in range it now is a stable 13 and doesn't move on rovergauge while driving
Reset base idle!and stepper fault code remains clear.
No more idle hunting coming off load.
Ps:still have to run iac valve minus washer to get decent range readings,
So will redo the rocker covers as well may well bring reading nearer mid range.
Heads were barely skimmed but guessing the faces weren't quite flat mating so there's the air leak.
Although not fully in range it now is a stable 13 and doesn't move on rovergauge while driving
Reset base idle!and stepper fault code remains clear.
No more idle hunting coming off load.
Ps:still have to run iac valve minus washer to get decent range readings,
So will redo the rocker covers as well may well bring reading nearer mid range.
If the OP is having running issues the first thing he should do is close the Rogergauge program and put his laptop back in the house, now with that sorted he can stop chasing his tail hoping a solution will miraculously pop out of his computer screen and he can concentrate on going back to basics.
In essence the OP should take a close look at his ignition system and check for any vacuum leaks, even if he believes he's done this already, this is how idle issues should be addressed before any PC based software is opened. The simple truth is your laptop will never be able to fix a fouled or worn spark plug, a burnt HT lead, or a failing spark plug extender.... all of which (amongst many other ignition elements) are far more common sources of idle issues than anything you'll see on your computer.
My advice would be for the OP to go back to basics and start from the beginning, and your laptop running Rovergauge is definitely not the beginning
Good luck with finding your issue.
In essence the OP should take a close look at his ignition system and check for any vacuum leaks, even if he believes he's done this already, this is how idle issues should be addressed before any PC based software is opened. The simple truth is your laptop will never be able to fix a fouled or worn spark plug, a burnt HT lead, or a failing spark plug extender.... all of which (amongst many other ignition elements) are far more common sources of idle issues than anything you'll see on your computer.
My advice would be for the OP to go back to basics and start from the beginning, and your laptop running Rovergauge is definitely not the beginning
Good luck with finding your issue.
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