Chimaera 500 Engine Problems
Discussion
Hi Everybody,
This is my first post here, so go easy please.
I've been looking through the past posts and can't find any problems similar to mine so I'm hoping somebody can point me in the right direction.
Here goes-
The car is a '98 Chimaera 500. When the car is first started it runs poorly. Under 3200rpm it has a serious lack of power and runs very lumpy. Above 3200rpm it is just fine. As the engine warms up it gets gradually worse until it gets to about 80 degrees. If the car is then left to idle, after about a minute the revs die to just above stalling, then they 'catch' again and the engine idle roughly for about 20 seconds. After this point, the revs climb momentarily to about 1500rpm and then settle to about 1000. When the car has been allowed to do this little routine everything is perfect!
If you don't allow the car to idle, the problem persists until you do. Also, if you have to pull away in that 20 second window, the car has hardly any power until you hit 3200rpm and the whole process must be restarted.
The car has been to 2 separate garages who were both convinced that they had fixed the problem - presumably they had left the car to idle while warm.
Any help would be very welcome.
Bert
This is my first post here, so go easy please.
I've been looking through the past posts and can't find any problems similar to mine so I'm hoping somebody can point me in the right direction.
Here goes-
The car is a '98 Chimaera 500. When the car is first started it runs poorly. Under 3200rpm it has a serious lack of power and runs very lumpy. Above 3200rpm it is just fine. As the engine warms up it gets gradually worse until it gets to about 80 degrees. If the car is then left to idle, after about a minute the revs die to just above stalling, then they 'catch' again and the engine idle roughly for about 20 seconds. After this point, the revs climb momentarily to about 1500rpm and then settle to about 1000. When the car has been allowed to do this little routine everything is perfect!
If you don't allow the car to idle, the problem persists until you do. Also, if you have to pull away in that 20 second window, the car has hardly any power until you hit 3200rpm and the whole process must be restarted.
The car has been to 2 separate garages who were both convinced that they had fixed the problem - presumably they had left the car to idle while warm.
Any help would be very welcome.
Bert
quote:
Hi Everybody,
This is my first post here, so go easy please.
I've been looking through the past posts and can't find any problems similar to mine so I'm hoping somebody can point me in the right direction.
Here goes-
The car is a '98 Chimaera 500. When the car is first started it runs poorly. Under 3200rpm it has a serious lack of power and runs very lumpy. Above 3200rpm it is just fine. As the engine warms up it gets gradually worse until it gets to about 80 degrees. If the car is then left to idle, after about a minute the revs die to just above stalling, then they 'catch' again and the engine idle roughly for about 20 seconds. After this point, the revs climb momentarily to about 1500rpm and then settle to about 1000. When the car has been allowed to do this little routine everything is perfect!
If you don't allow the car to idle, the problem persists until you do. Also, if you have to pull away in that 20 second window, the car has hardly any power until you hit 3200rpm and the whole process must be restarted.
The car has been to 2 separate garages who were both convinced that they had fixed the problem - presumably they had left the car to idle while warm.
Any help would be very welcome.
Bert
3200 rpm is about the point the ECU drops out of closed loop mode. I strongly suspect you have a faulty lambda sensor or other sensor fault that is throwing the ECU out in closed-loop mode. Some, but not all, of these faults can be detected by the ECU and reported as ECU fault codes which your garage should be able to check.
I'm certainly no expert and have no direct experience of this type of fault (disclaimers out of the way then
).
Just a thought but it sounds as though the ECU is 're-learning' on every start up? I don't know what the memory is like in these units but due to the fact that to reset the ECU you have to disconnect the battery, it implies to me that there must be a permanent feed to it when the keys out of the ignition, which possibily may not be connected?
It certainly does sound like ECU fault or one of the components/wiring feeding the ECU though, you would expect it to show up on an error code reader
.
Again don't forget that the error codes are reset by the removal of power to the ECU, is it standard practice for these readers to be connected whilst running, if so the theory above holds more water if they are connected when the engine is not running(if you c what I mean)
Any experts out there that could add to this?
Obviously all IMHO (second disclaimer
)
Harry
). Just a thought but it sounds as though the ECU is 're-learning' on every start up? I don't know what the memory is like in these units but due to the fact that to reset the ECU you have to disconnect the battery, it implies to me that there must be a permanent feed to it when the keys out of the ignition, which possibily may not be connected?
It certainly does sound like ECU fault or one of the components/wiring feeding the ECU though, you would expect it to show up on an error code reader
. Again don't forget that the error codes are reset by the removal of power to the ECU, is it standard practice for these readers to be connected whilst running, if so the theory above holds more water if they are connected when the engine is not running(if you c what I mean
) Any experts out there that could add to this?
Obviously all IMHO (second disclaimer
) Harry
I was reading a post by Peter Humphries in another thread (SOB! Chimaera won't play) which sounds like a possible suspect.
He says that there is a certain amount of adaptive fuelling going on in the ECU which is only recalculated under certain conditions ie. Temp within a certain range, correct RPM for a certain amount of time.
These are pretty much the conditions under which my car sorts itself out.
My question is - do these setting get lost when the engine is turned off, or is it possible that there is a missing live feed to the ECU which is causing the loss of the settings?
He says that there is a certain amount of adaptive fuelling going on in the ECU which is only recalculated under certain conditions ie. Temp within a certain range, correct RPM for a certain amount of time.
These are pretty much the conditions under which my car sorts itself out.
My question is - do these setting get lost when the engine is turned off, or is it possible that there is a missing live feed to the ECU which is causing the loss of the settings?
I've had various problems of this sort over the last hundred thousand miles or so, and each time I've taken it into Tower View they've diagnosed the problem and sorted it good as new. In many cases there were several faults that combined to produce the problem, such as weak spark, faulty fuel pressure regulator, failed lambda sensor, throttle pot, road speed sensor, coolant temp sensor, hotwire, air leak, dirty stepper motor, clogged fuel filter, faulty injector. The list goes on and on. Even had a dodgy ECU earth once that caused some truly bizarre symptoms. Point is some of these problems take a lot of knowledge and experience to solve, and not all servicing agents are this good. It sounds like you need to find a really good specialist who knows the 14 CUX/hotwire system inside out, to get to the bottom of this.
Notice you live in the West Midlands.....take it over to TVR Power in Coventry (the guys who built the engine in the first place). I had a long running fault on my car which had defeated several dealers and Power diagnosed and fixed it very quickly. Talk to Dom, who I understand used to work in V8 engine development at the factory.
quote:
Notice you live in the West Midlands.....take it over to TVR Power in Coventry (the guys who built the engine in the first place). I had a long running fault on my car which had defeated several dealers and Power diagnosed and fixed it very quickly. Talk to Dom, who I understand used to work in V8 engine development at the factory.
Ford, is the problem fully sorted now? Very nice pic of your car in the 'Lets See Ya Cars' thread BTW.
Mike
quote:
quote:
Notice you live in the West Midlands.....take it over to TVR Power in Coventry (the guys who built the engine in the first place). I had a long running fault on my car which had defeated several dealers and Power diagnosed and fixed it very quickly. Talk to Dom, who I understand used to work in V8 engine development at the factory.
Ford, is the problem fully sorted now? Very nice pic of your car in the 'Lets See Ya Cars' thread BTW.
Mike
Mike, the car is still going like a dream and I've all but forgotten those early painful days of TVR ownership - Had the odd minor problem but nothing to do with the engine and easy to sort out - I look forward to going to work now and pray for sunshine!!!
John.
Just to update everybody.
The car spent the week in the garage last week. From what I'm told, just about everything was checked/changed during the week, but the problem is still there!
Again they were convinced that the problems had gone away.
It's actually a real nightmare to tell if the problem has been cured or not, since you have to run the car until warm for the worst symptoms to show (and even then they cure themselves within a minute if the car is just left alone), so I can't really fault the garage so far.
Apparently the ECU doesn't report any faults when the gizmo is plugged in.
I'm currently running an ECU from another car to see if that cures the problem, but the signs aren't looking good.
I think it's just going to be a case of changing all of the sensors one by one.......
The car spent the week in the garage last week. From what I'm told, just about everything was checked/changed during the week, but the problem is still there!
Again they were convinced that the problems had gone away.
It's actually a real nightmare to tell if the problem has been cured or not, since you have to run the car until warm for the worst symptoms to show (and even then they cure themselves within a minute if the car is just left alone
), so I can't really fault the garage so far. Apparently the ECU doesn't report any faults when the gizmo is plugged in.
I'm currently running an ECU from another car to see if that cures the problem, but the signs aren't looking good.
I think it's just going to be a case of changing all of the sensors one by one.......
If the engine can't find his right idle rpm, you have to screw a long black piece out of the airbox. It's about 4in long and about 1in diameter. It has 1/2" male thread on it and a flat graphite gasket is fitted between the piece and the aluminium airbox. A socket with 4 electric wires is attached to it. Once you've got it out of the engine the only thing you have to do is clean it in fuel while you move the pin repeatedly in and out of the shaft. Frequent mistake is just cleaning the spring that's attached around the pin while cleaning the shaft is often forgotten, while this is most important. For the other problems I can't help and I think they're to complex to solve them yourself so perhaps you should go to a TVR dealer or a Rover V8 specialist.
Greetz,
a Belgian Chimaera 500 owner.
Greetz,
a Belgian Chimaera 500 owner.
quote:
If the engine can't find his right idle rpm, you have to screw a long black piece out of the airbox. It's about 4in long and about 1in diameter. It has 1/2" male thread on it and a flat graphite gasket is fitted between the piece and the aluminium airbox. A socket with 4 electric wires is attached to it. Once you've got it out of the engine the only thing you have to do is clean it in fuel while you move the pin repeatedly in and out of the shaft. Frequent mistake is just cleaning the spring that's attached around the pin while cleaning the shaft is often forgotten, while this is most important. For the other problems I can't help and I think they're to complex to solve them yourself so perhaps you should go to a TVR dealer or a Rover V8 specialist.
Greetz,
a Belgian Chimaera 500 owner.
I think that’s the stepper motor you've just described there
. I'd like to think that's been looked at by this stage in the fault finding process. However from my (large) folder of receipts that came with the car from the previous owner
. It had a period stretching over months in and out the garage for a idle problem, including exchanging two stepper motors. The bills stopped for that one when they rewired back from the stepper motor to the ECU, just a thought if this is the area of concern. Harry
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