kangarooing 4.6 Chimaera
Discussion
Hi all
I have a 1996 Chimaera with the 4.6 MC1 road cam , Tornado chipset , its running poorly in lower rev ranges,splittering/missfiring/kangarooing.
Its fine when going hard with terrific punch after 3,250rpm , but doesnt like crusing .
Seems poor on petrol as well.
Apart from driving flat out has anyone any ideas? I cannot find a local garage who is competant in this kind of car.so i,m a bit stuck !
Is there any home enthusiasts/tuners out there on south coast [Hastings or Kent ]who could offer help? [paid]
I have a 1996 Chimaera with the 4.6 MC1 road cam , Tornado chipset , its running poorly in lower rev ranges,splittering/missfiring/kangarooing.
Its fine when going hard with terrific punch after 3,250rpm , but doesnt like crusing .
Seems poor on petrol as well.
Apart from driving flat out has anyone any ideas? I cannot find a local garage who is competant in this kind of car.so i,m a bit stuck !
Is there any home enthusiasts/tuners out there on south coast [Hastings or Kent ]who could offer help? [paid]
Has it ever run properly on the existing setup? If it has, then it implies something has gone wrong, probably a sensor or wiring fault or possibly an unmetered air leak into the plenum. You could try resetting the ECU by unplugging it for a few seconds. If the ECU has gone into fault mode this will clear it and may improve the situation. (If the problem which caused it to go into fault mode is still present it may still not work very well and may go back into fault mode after a while.)
If the problem was introduced by a cam / engine / chip change then it's still possible you have a sensor/wiring fault but probably more likely that you simply have the wrong fuel map. Has your ECU map been developed for that cam in that engine, or is it just a generic chip? If it isn't specific to your engine it may simply be that you need to get it mapped properly.
If the problem was introduced by a cam / engine / chip change then it's still possible you have a sensor/wiring fault but probably more likely that you simply have the wrong fuel map. Has your ECU map been developed for that cam in that engine, or is it just a generic chip? If it isn't specific to your engine it may simply be that you need to get it mapped properly.
Twin pipe said:
RPI
The tornado chip is just a chip with a fuel map on it. It doesn't give the ECU any magical new capabilities. If the 14CUX was capable of coping with changes to the engine spec without remapping, there wouldn't be a market for the tornado chip and Mark Adam's mapping work in the first place and the ECU would be sealed for life. Since this ECU use a mass air flow sensor for load, it will compensate for changes in the engine characteristics to some extent, so if it's right for one engine it will be close for other similar engines, that doesn't mean it will be spot on.You need to have a fuel map which is right for your engine. If it's a standard engine spec then you will find that there are maps available that will be about right for it. But unless you happen to find a map that is right for that particular engine spec (capacity, cam type/timing, ignition curve, compression, induction, exhaust) the fueling will be out. How far out will depend on how close the map was to what the engine needed.
It's also possible that the map is correct but there's a hardware fault that is causing the ECU to give the wrong fueling, but the evidence you've given us so far isn't enough to draw any conclusions either way.
GreenV8S is right as usual.
I don’t know whether I have ever seen the car on the rolling road, but either way it should be better than you are finding it! If it has an off-the-shelf chip, then it is the distilled essence of many similar (?) vehicles I have seen. However this can only ever be the “average” case. It is also very important that the car runs the correct fuel pressure, which is 2.5 Bar or 36 PSI (no vacuum).
Maybe it would help you to know that I've personally set up over 2,500 vehicles, and no two of them are quite the same.
The change in behaviour over 3250 RPM is very relevant, since this is the point at which it comes off Lambda control (i.e. the Oxygen sensors in the exhaust are not used). This indicates that you may have an Oxygen sensor problem. It’s quite easy to check if you have a digital voltmeter, and I can PM a fault-finding guide to help you.
It's also possible that you have an injector or other sensor problem.
Additionally the ECU does store fault codes, which can be read with suitable equipment. Although the Tornado software does illuminate the MIL (Malfunction Indicator Lamp) when fault codes are present, it is not correctly wired by TVR in earlier cars so will never come on!
Is this any help to you? Please let me know if there is anything else you need.
I don’t know whether I have ever seen the car on the rolling road, but either way it should be better than you are finding it! If it has an off-the-shelf chip, then it is the distilled essence of many similar (?) vehicles I have seen. However this can only ever be the “average” case. It is also very important that the car runs the correct fuel pressure, which is 2.5 Bar or 36 PSI (no vacuum).
Maybe it would help you to know that I've personally set up over 2,500 vehicles, and no two of them are quite the same.
The change in behaviour over 3250 RPM is very relevant, since this is the point at which it comes off Lambda control (i.e. the Oxygen sensors in the exhaust are not used). This indicates that you may have an Oxygen sensor problem. It’s quite easy to check if you have a digital voltmeter, and I can PM a fault-finding guide to help you.
It's also possible that you have an injector or other sensor problem.
Additionally the ECU does store fault codes, which can be read with suitable equipment. Although the Tornado software does illuminate the MIL (Malfunction Indicator Lamp) when fault codes are present, it is not correctly wired by TVR in earlier cars so will never come on!
Is this any help to you? Please let me know if there is anything else you need.
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