V8S - Idle difficulties.. V weird
Discussion
Hi
I've been having what I think I traced to overfuelling issues especially at start up for a while. Checked and Changed usual suspects and only fault or odd reading on Rover Gauge software was throttle pot. I change this and it seemed ok for a while. I even changed the ECU out for another working one during this process.
Then recently I've had trouble with starting and idling especially when can has been used and is up to operating temp. I used the Rover Gauge software to check the idle control valve and used it to retract it manually (i.e. overriding the ECUs control) to let more air in as an experiment. Its never idled and revved from cold better. So i thought its the valve. I buy a new one, install and reset ECU. It starts and idles fine so i think I've cracked it.
Then the last few weeks its been running terrible and on Tuesday (on way to important hospital appointment of course!) it stalled soon after starting and wouldn't restart. It may have flooded due to lack of air causing lack of ignition so I pulled injector impact sensor out, effectively cutting off the fuel and tried to start. It ran on the residue fuel and pressure for a few seconds then cut out as expected. I then pulled the idle control valve plug out (making it locked fully retracted to provide max air flow) and then it started first time. I ran like this for a bit but idle was at 2000rpm and then starting hunting all over the place. I plugged valve back in and rpm settled back at 950rpm ish which is good. After hospital I started it again and it was awful. Rpm at idle was about 400rpm and nearly stalling. I nursed it home with careful heel toe revving and braking with clutch.
Anyone had anything similar on their V8? I know the idle control works a bit different on the V6 but any suggestions welcome.
Thanks
Rob
I've been having what I think I traced to overfuelling issues especially at start up for a while. Checked and Changed usual suspects and only fault or odd reading on Rover Gauge software was throttle pot. I change this and it seemed ok for a while. I even changed the ECU out for another working one during this process.
Then recently I've had trouble with starting and idling especially when can has been used and is up to operating temp. I used the Rover Gauge software to check the idle control valve and used it to retract it manually (i.e. overriding the ECUs control) to let more air in as an experiment. Its never idled and revved from cold better. So i thought its the valve. I buy a new one, install and reset ECU. It starts and idles fine so i think I've cracked it.
Then the last few weeks its been running terrible and on Tuesday (on way to important hospital appointment of course!) it stalled soon after starting and wouldn't restart. It may have flooded due to lack of air causing lack of ignition so I pulled injector impact sensor out, effectively cutting off the fuel and tried to start. It ran on the residue fuel and pressure for a few seconds then cut out as expected. I then pulled the idle control valve plug out (making it locked fully retracted to provide max air flow) and then it started first time. I ran like this for a bit but idle was at 2000rpm and then starting hunting all over the place. I plugged valve back in and rpm settled back at 950rpm ish which is good. After hospital I started it again and it was awful. Rpm at idle was about 400rpm and nearly stalling. I nursed it home with careful heel toe revving and braking with clutch.
Anyone had anything similar on their V8? I know the idle control works a bit different on the V6 but any suggestions welcome.
Thanks
Rob
Hi Rob
When I had the car it would occasionally start and idle at 2000rpm.
Moving the car just a small amount forwards would then make it drop down to normal - so I thought it may be something to do with the speed sensor but as it happened so infrequently it was impossible to track down.
The idle control valves are notoriously rubbish - where did you get your replacement from as I understand there are a lot of rubbish Chinese ones about - some work some don't and some are just plain rubbish.
I did consider doing away with it altogether - the pipe coming out the other end of the valve if you restrict it alters the idle speed - I considered making 2 idle speeds possible using a switch - higher for starting and some sort of solenoid valve to drop it down once warmed up by restricting airflow through that pipe if that makes any kind of sense.
As you have found if you disconnect the wiring to the valve once its up to temperature it runs fine when hot but is a pig when cold tending to stall as the idle speed is too low.
My suspicion is that your new valve could be sticking but it is a guess.
Chris
When I had the car it would occasionally start and idle at 2000rpm.
Moving the car just a small amount forwards would then make it drop down to normal - so I thought it may be something to do with the speed sensor but as it happened so infrequently it was impossible to track down.
The idle control valves are notoriously rubbish - where did you get your replacement from as I understand there are a lot of rubbish Chinese ones about - some work some don't and some are just plain rubbish.
I did consider doing away with it altogether - the pipe coming out the other end of the valve if you restrict it alters the idle speed - I considered making 2 idle speeds possible using a switch - higher for starting and some sort of solenoid valve to drop it down once warmed up by restricting airflow through that pipe if that makes any kind of sense.
As you have found if you disconnect the wiring to the valve once its up to temperature it runs fine when hot but is a pig when cold tending to stall as the idle speed is too low.
My suspicion is that your new valve could be sticking but it is a guess.
Chris
Cheers for the reply. Good to see you're still lurking on the forums! Helps that the previous owner / rebuilder is still about.
Well I got my replacement part from here:
http://www.lrdirect.com/ETC6660-Stepper-Motor-Sole...
It seems identical to the one I took out.
Also, I replaced this new one with the old one in the street on the way home! it didn't make a great difference apart from a slightly higher idle.
Well I got my replacement part from here:
http://www.lrdirect.com/ETC6660-Stepper-Motor-Sole...
It seems identical to the one I took out.
Also, I replaced this new one with the old one in the street on the way home! it didn't make a great difference apart from a slightly higher idle.
Hi
yes i just checked tune resistor and tried as much as possible to investigate wiring and connections in footwell.
Also check yellow connector inside. Looks fine.
Ive checked the washer and swapper it out for a copper one and soft gasket type one. Same thing.
just been fiddling with the stepper motor operation using rover gauge over ride function and its effect on the idle. I found that even with manually opening the valve fully, it still had trouble starting and idling at times. Seems almost random now. arrgghh. Might be time for the garage. Hate giving in but Ive tried everything that has been suggested on forum, internet, heath bible..
yes i just checked tune resistor and tried as much as possible to investigate wiring and connections in footwell.
Also check yellow connector inside. Looks fine.
Ive checked the washer and swapper it out for a copper one and soft gasket type one. Same thing.
just been fiddling with the stepper motor operation using rover gauge over ride function and its effect on the idle. I found that even with manually opening the valve fully, it still had trouble starting and idling at times. Seems almost random now. arrgghh. Might be time for the garage. Hate giving in but Ive tried everything that has been suggested on forum, internet, heath bible..
Edited by gizzardio on Wednesday 4th September 22:06
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