Discussion
Hello There, I have been enjoying my new chim 400 a lot during the last weeks (we had a lot of sunshine in Germany
), but there is one strange behaviour that keeps puzzling me. the car has been chipped, new dizzy, dizzy amp, plugs, magnecor, fuel pressure regulator. when I disconnect the ECU , wait for a couple of minutes, reconnect everything is ok. The engine purrs like a cat, no shunting at all just as it should be. if I accelerate for the first time, flooring the pedal hard and reving to about 5800 through the gears (not in fifth gear though, probably because it is not green)and then coast to a standstill, the engine is idling at anything between 1200 to 1800 rpm and it takes up to 7 or 8 seconds for the ECU to bring the engine back to 800. after that as soon as I am driving with more than 2000 rpm I always have this very fast idle and no engine breaking when lifting the loud foot.the car will roll in gear with 2000 rpm until again after 7 to 8 seconds the ECU brings it back to normal. this will go on, until I disconnect the ECU, then the car runs perfect until I first accelerate with the pedal hard against the floor and the game starts again. Any suggestions how to get rid of that are greatly welcome.
), but there is one strange behaviour that keeps puzzling me. the car has been chipped, new dizzy, dizzy amp, plugs, magnecor, fuel pressure regulator. when I disconnect the ECU , wait for a couple of minutes, reconnect everything is ok. The engine purrs like a cat, no shunting at all just as it should be. if I accelerate for the first time, flooring the pedal hard and reving to about 5800 through the gears (not in fifth gear though, probably because it is not green)and then coast to a standstill, the engine is idling at anything between 1200 to 1800 rpm and it takes up to 7 or 8 seconds for the ECU to bring the engine back to 800. after that as soon as I am driving with more than 2000 rpm I always have this very fast idle and no engine breaking when lifting the loud foot.the car will roll in gear with 2000 rpm until again after 7 to 8 seconds the ECU brings it back to normal. this will go on, until I disconnect the ECU, then the car runs perfect until I first accelerate with the pedal hard against the floor and the game starts again. Any suggestions how to get rid of that are greatly welcome.Edited by Krautchimaera on Tuesday 19th August 16:43
Do you definitely have to unplug the ECU to cure the problem, or is it sufficient just to stop and restart the engine? If you definitely need to reset the ECu then perhaps your ECU is going into 'limp home' mode. In that case, a fault code reader might show what is making the ECU unhappy.
well I have cleaned the stepper motor cause this was the first thing that came into my mind. so taht should be ok.
yes I have to unplug the ECU.I tried without four two days but the engine never behaves as it should. if I reset the ECU all is perfect as described. I do not know if there is a TVR dealer near me, will a Land Rover dealer be ok, cause there is one local. I suppose the device needed is the same?
yes I have to unplug the ECU.I tried without four two days but the engine never behaves as it should. if I reset the ECU all is perfect as described. I do not know if there is a TVR dealer near me, will a Land Rover dealer be ok, cause there is one local. I suppose the device needed is the same?
A fault code reader is a must for this sort of problem. Check the connections are OK on the air flow meter as I think that this caused me quite a few problems of the same kind.
The AFM can go open circuit for a short time without causing a fault code to be generated. It does though tend to cause a slight stuttering of the engine or even short cut out depending on the state of the connections.
Mike
The AFM can go open circuit for a short time without causing a fault code to be generated. It does though tend to cause a slight stuttering of the engine or even short cut out depending on the state of the connections.
Mike
SC Power have solution enabling you to adjust your idle speed to overcome your problem. Visit their web site www.sc-power.co.uk and look for Stepper hose air restrictor. This enable you to control eratic engine idle speed. Not expewnsive and works. The standard restictor enables the engine to idle at about 900rpm, if after fitting your engine speed is too low the restictor can be opened up to increase air flow with resulting increase in idle rpm.
Hello CHGRIFF, I had a look at the link you sent me and from the explanation it seems to be exactly what I am looking for.
If I understand it correctly, it is just a sort of disc or bush that reduces the inner diametre of the hose. not that I am tight, but having a toollathe in my workshop, I could do this easily myself in a couple of minutes if only I had a sketch, or knew the size of the inner hole of the reducing disc.
Soo if anybody knows, please let me know, otherwise I will order the item next week.
If I understand it correctly, it is just a sort of disc or bush that reduces the inner diametre of the hose. not that I am tight, but having a toollathe in my workshop, I could do this easily myself in a couple of minutes if only I had a sketch, or knew the size of the inner hole of the reducing disc.
Soo if anybody knows, please let me know, otherwise I will order the item next week.
Check the throttle potentiometer is correctly adjusted. I have injector monitor LEDS on my car (they flash as the injectors pulse) and having adjusted the throttle pot, I can now see the injectors shutting off (giving engine braking) when I lift off the throttle. It does seem dependent on airflow and engine revs - they don't always cut off immediately, or totally. They cut back in again at about 1000 rpm.
As for the high idle dropping to 800rpm after 7-8 seconds, I thought this was normal??!!
As for the high idle dropping to 800rpm after 7-8 seconds, I thought this was normal??!!
Well I have made all the obvious and easy to do checks. I checked the timing marks and found them to be out, so corrected them with tippex, I checked the advance mechanism, checked the vacuum pipe and connections, I adjusted the AFM to the 1.8 volts ( as on RPI website), i adjusted the throttle pod by filing it to .44. so everything is as it should. when I drive the car all is ok. I still have a little high idle ~ 1200 rpm, but the ECU regulates that usually within 2-3 seconds.
only after flooring the pedal hard and reving through the gears it will not go down below 1800 -2000 before at least 7 - 9 seconds. once I am at that point, taking the engine at any speed above 2000 rpm results with this high idle again for the 7-9 seconds.
very annoying in traffic, cause you only slightly accellerate and then take you foot of, but the car has no engine braking and you always have to be carefull, not to hit the car in front.
I first thought it was mechanical cause it is only after flooring hard, but then this could not be "repaired" by unplugging the ECU.
so I am a bit lost at the moment, but I should try the sc kit I think, this would make sense to me.
only after flooring the pedal hard and reving through the gears it will not go down below 1800 -2000 before at least 7 - 9 seconds. once I am at that point, taking the engine at any speed above 2000 rpm results with this high idle again for the 7-9 seconds.
very annoying in traffic, cause you only slightly accellerate and then take you foot of, but the car has no engine braking and you always have to be carefull, not to hit the car in front.
I first thought it was mechanical cause it is only after flooring hard, but then this could not be "repaired" by unplugging the ECU.
so I am a bit lost at the moment, but I should try the sc kit I think, this would make sense to me.
Hi Krautchimaera,
I guess nevertheless it's a problem with the stepper motor. Only cleaning this bit will not always solve the problem. It's an electromechanical component, which can wear out internally. There have been some reports that only cleaning this part often doesn't make a great difference. I changed mine and it made a big difference concerning idle and response of the throttle.
As I guess, we're both located in Germany, I would be willing to send you one of mine, which is working pretty good, for test reason. If you detect a better behaviour of your idle problem, you could buy a new one and sent back mine. Please feel free to contact me.
Best regards
Rainer
I guess nevertheless it's a problem with the stepper motor. Only cleaning this bit will not always solve the problem. It's an electromechanical component, which can wear out internally. There have been some reports that only cleaning this part often doesn't make a great difference. I changed mine and it made a big difference concerning idle and response of the throttle.
As I guess, we're both located in Germany, I would be willing to send you one of mine, which is working pretty good, for test reason. If you detect a better behaviour of your idle problem, you could buy a new one and sent back mine. Please feel free to contact me.
Best regards
Rainer
Get it warmed up and idling at the right speed then disconnect the stepper motor. If the symptoms all stop, you know the stepper motor is somehow causing it and can look at restrictors, changing the base idle etc to address it. But it may have another cause entirely, so confirm it before you start trying to fix anything.
I will take the car for a drive to northern France and Luxembourg over the weekend. I have all the necessary tools, a second ECU a second stepper motor and the lot with me and about 700 miles of road for all sorts of test. Maybe I find out something during that trip.
Most important is that the weathers stays good, cause driving with the hood down is what makes gives me the greatest pleasure with my TVR.
hello Rainer, thanks alot for your offer, but I still have the wreck of my first TVR when some drunk driver tried to kill me. so I always have most of the parts double and that stepper motor was new.
I will keep you updated....
Most important is that the weathers stays good, cause driving with the hood down is what makes gives me the greatest pleasure with my TVR.
hello Rainer, thanks alot for your offer, but I still have the wreck of my first TVR when some drunk driver tried to kill me. so I always have most of the parts double and that stepper motor was new.
I will keep you updated....
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