Idle problem on 400se
Discussion
I have a real problem with the car idleing when it gets warm.The car is fine starting from cold and rev's lovely but as soon as the thermostat opens and i leave it to idle it dies on me, a blip of the throttle and its fine again!
Bearing in mind it has been off the road for 12 months whilst I have replaced all the fuel pipes , swirl pot and pump as well as restoring the chassis could it be anything that I have caused myself?
The car used to idle ok before I took it off the road, and still not fully finished its still not taxed to give it a good run at the moment.
The fuel filter was 10 years old when i took it off! and the car has an adjustable fuel pressure regulator, could it now be overfueling or could it be the temperature sensor?
Help please!!
Andy.
Bearing in mind it has been off the road for 12 months whilst I have replaced all the fuel pipes , swirl pot and pump as well as restoring the chassis could it be anything that I have caused myself?
The car used to idle ok before I took it off the road, and still not fully finished its still not taxed to give it a good run at the moment.
The fuel filter was 10 years old when i took it off! and the car has an adjustable fuel pressure regulator, could it now be overfueling or could it be the temperature sensor?
Help please!!
Andy.
Thanks for the reply's everyone,
Would any of these probable causes just have happened with the car standing for a while? The engine and ancillaries havn't been disturbed during the chassis resto, being a pre hotwire car there is no steppa motor fitted just the overun valve which has been cleaned and sorted once before due to the opposite happening i.e ticking over at 2000 rpm!
The throttle pot sounds like a possibility but again would this just happen through standing?
Tim, yours sounds like the one I like best! could it be as simple as reseting the idle or mixture? I guess the work that has been done on the fuel system could account for that.
One other thing there is never a problem re starting the car once it has cut out unlike seems to happen on threads along a similar line.
If anyone has any other opinion,suggestions all greatfully received!
cheers.
>> Edited by ANDYM on Wednesday 12th March 08:29
Would any of these probable causes just have happened with the car standing for a while? The engine and ancillaries havn't been disturbed during the chassis resto, being a pre hotwire car there is no steppa motor fitted just the overun valve which has been cleaned and sorted once before due to the opposite happening i.e ticking over at 2000 rpm!
The throttle pot sounds like a possibility but again would this just happen through standing?
Tim, yours sounds like the one I like best! could it be as simple as reseting the idle or mixture? I guess the work that has been done on the fuel system could account for that.
One other thing there is never a problem re starting the car once it has cut out unlike seems to happen on threads along a similar line.
If anyone has any other opinion,suggestions all greatfully received!
cheers.
>> Edited by ANDYM on Wednesday 12th March 08:29
Thanks again Tim,
Is it just as simple as turning the screw on the side of the throttle body or does the base idle have to be reset?
I will use this approach to keep it from cutting out while I take it down to the rolling road just to see if there is anything more complicated going wrong,its due its annual session on the rollers anyway.
Andy.
Is it just as simple as turning the screw on the side of the throttle body or does the base idle have to be reset?
I will use this approach to keep it from cutting out while I take it down to the rolling road just to see if there is anything more complicated going wrong,its due its annual session on the rollers anyway.
Andy.
You can unscrew the idle screw (beside throttle) normally with an allen key, older cars have a slot for screw driver, without adjusting throttle pot, this should get you "rolling" but don't adjust the throttle butterfly stop as this will then require resetting the pot with a multimeter.
Tim
Tim
Working from memory here (can check on the car at the weekend if it's important), but the 400SE I look after has the original rover Idle Speed Control Valve (ISCV) setup - right? Typically these are totally unreliable in service (especially on low usage vehicles), especially the erlier types. They usually stick, or are slow to react - not good in a cammy engine which is quick to react! When people talk about idle problems (assuming the engine is in good state of service and tune), I find that 90% of the time it is the ISCV playing up. You could waste a weekend cleaning it, and it may change the symptoms for 5 minutes or so, but the cure is to replace it. Certainly if you don't know when it was last changed then it will be worth doing as they are not the end of the world, money wise.
altenatively I have found that jacking up the base idle is a very good start point. To do this warm the engine, clamp off the ISCV lines and set the idle speed to just below idle with it out of the loop. remove the clamps and the engine is less relient on it.
Of course the last thing you can do is jack up the base idle altogether. I find that by setting a hot idle of 1300rpm on this 400SE we have cured the stalling issue - for us it was a case of petite lady driver + stally tvr + Power steering + fairly dangerous so....
Hope that helps.
altenatively I have found that jacking up the base idle is a very good start point. To do this warm the engine, clamp off the ISCV lines and set the idle speed to just below idle with it out of the loop. remove the clamps and the engine is less relient on it.
Of course the last thing you can do is jack up the base idle altogether. I find that by setting a hot idle of 1300rpm on this 400SE we have cured the stalling issue - for us it was a case of petite lady driver + stally tvr + Power steering + fairly dangerous so....
Hope that helps.
Nickleby4 said: Working from memory here (can check on the car at the weekend if it's important), but the 400SE I look after has the original rover Idle Speed Control Valve (ISCV) setup - right? Typically these are totally unreliable in service (especially on low usage vehicles), especially the erlier types. They usually stick, or are slow to react - not good in a cammy engine which is quick to react! When people talk about idle problems (assuming the engine is in good state of service and tune), I find that 90% of the time it is the ISCV playing up. You could waste a weekend cleaning it, and it may change the symptoms for 5 minutes or so, but the cure is to replace it. Certainly if you don't know when it was last changed then it will be worth doing as they are not the end of the world, money wise.
altenatively I have found that jacking up the base idle is a very good start point. To do this warm the engine, clamp off the ISCV lines and set the idle speed to just below idle with it out of the loop. remove the clamps and the engine is less relient on it.
Of course the last thing you can do is jack up the base idle altogether. I find that by setting a hot idle of 1300rpm on this 400SE we have cured the stalling issue - for us it was a case of petite lady driver + stally tvr + Power steering + fairly dangerous so....
Hope that helps.
I've blanked this off completely on several occasions with very "hot" engines,
Nickleby4 said: Working from memory here (can check on the car at the weekend if it's important), but the 400SE I look after has the original rover Idle Speed Control Valve (ISCV) setup - right? Typically these are totally unreliable in service (especially on low usage vehicles), especially the erlier types. They usually stick, or are slow to react - not good in a cammy engine which is quick to react! When people talk about idle problems (assuming the engine is in good state of service and tune), I find that 90% of the time it is the ISCV playing up. You could waste a weekend cleaning it, and it may change the symptoms for 5 minutes or so, but the cure is to replace it. Certainly if you don't know when it was last changed then it will be worth doing as they are not the end of the world, money wise.
altenatively I have found that jacking up the base idle is a very good start point. To do this warm the engine, clamp off the ISCV lines and set the idle speed to just below idle with it out of the loop. remove the clamps and the engine is less relient on it.
Of course the last thing you can do is jack up the base idle altogether. I find that by setting a hot idle of 1300rpm on this 400SE we have cured the stalling issue - for us it was a case of petite lady driver + stally tvr + Power steering + fairly dangerous so....
Hope that helps.
Hi Nickleby4,
Not wishing to sound too mechcanicaly ignorant but is this ICSV the same as whats refered to as the overun valve on the rear of the Plenum chamber?
If this is the case I think I will go ahead and replace it because it has caused problems in the past albeit the opposite of whats currently happening.
Cheers,
Andy.
stainless_steve said: Hi Andy
Have you sorted the problem out?
steve
Hi Steve,
As you can probably tell I haven't sorted it yet!
I have just a few bits to finish on the rear first then its around to the front again!
I am going to get the airflow meter reconditioned and probably replace the overun valve then a trip to the rollers.
Cheers,
Andy.
Ok I will throw this one open to anyone, is this ISCV (idle speed control valve) whats commonly called the overrun valve or is it something completely differant?
I cant find any referance to an ISCV on the pre Hotwire V8, only thing that comes close is the overrun valve.
Cheers
Andy.
I cant find any referance to an ISCV on the pre Hotwire V8, only thing that comes close is the overrun valve.
Cheers
Andy.
Gassing Station | Wedges | Top of Page | What's New | My Stuff