Misfire above 5000rpm
Discussion
Did a track day on Wednesday in the Tuscan (cats were back in so managed to get on with the noise limit) and found a bad misfire above 5000 rpm, it's been there before. I had changed the Plugs before the track day, also rerouted the crank sensor wire away from the leads as was getting a error on the diagnostics.
I knew its possible to get another chip which does something with the throttle pots above certain revs to stop this problem, but decided to try the spare chip I was given from a Sagaris (marked Tuscan S though) there is a clear improvement, but still not sure it's 100% right.
I knew its possible to get another chip which does something with the throttle pots above certain revs to stop this problem, but decided to try the spare chip I was given from a Sagaris (marked Tuscan S though) there is a clear improvement, but still not sure it's 100% right.
I reckon it's definitely to do with the chip. It'll be mapped to the decat and when you put the cats back in it'll be the wrong set up.
I set out to put my cats back in on Sat - MOT due in a week or so. Got the lower one off no probs but couldn't get the band clamp off the upper one. Was thinking of taking the cutter to it but a replacement clamp from Racing Green is £47 + vat
Anyone any ideas where I can get one cheaper? Oh and is the EPROM chip easy to find? Guess it's in amongst the fuses?
I set out to put my cats back in on Sat - MOT due in a week or so. Got the lower one off no probs but couldn't get the band clamp off the upper one. Was thinking of taking the cutter to it but a replacement clamp from Racing Green is £47 + vat
Anyone any ideas where I can get one cheaper? Oh and is the EPROM chip easy to find? Guess it's in amongst the fuses?
It's not been running a decat chip, when the car was rolling roaded at SRR the fueling was pretty much spot on with the decats in place so wasn't any point paying for a decat chip.
why can't you get the clamp off? is it just the nut too tight? If so a long reach socket and breaker bar should do the trick.
why can't you get the clamp off? is it just the nut too tight? If so a long reach socket and breaker bar should do the trick.
Mine was doing this at 5500 ish, kind of like hitting the rev limiter more than a miss. I have now changed the plugs, leads, coil pack, valve clearances are good, new lambda sensor to replace a screwed one, reset all diagnostics and its still bloody there. Im starting to think its to do with the mapping, the ecu has tusc 2 written on it in pen so not sure it its stock or not.
Noisy said:
why can't you get the clamp off? is it just the nut too tight? If so a long reach socket and breaker bar should do the trick.
It seems to be welded in place. Got the nut and bolt off and levered the clamp off about a third of the way but it just won't budge. Power do the clamp for £23 so I'm going to order one and then cut the existing one offBGB autosport said:
Mine was doing this at 5500 ish, kind of like hitting the rev limiter more than a miss. I have now changed the plugs, leads, coil pack, valve clearances are good, new lambda sensor to replace a screwed one, reset all diagnostics and its still bloody there. Im starting to think its to do with the mapping, the ecu has tusc 2 written on it in pen so not sure it its stock or not.
It's often a common fault that the spindles in the throttle bodies wear and causes some noise through the throttle pots. I am tempted to order a chip which is suppose to stop this, but seeing I fitted this other chip and it seems a lot better I might take it down to SRR and get them to run it and see what it's doing as its hard to test it on the open road.Jim Green said:
I thought maybe it would have been obvious who I was refering too. So to keep the peace I removed the original post. I'm not a person who likes to stir things up.
Just to add........ Always browse the Specialists Web Sites to get the best price. There can be some "Huge" price differences. I paid double the price for the identical part when If I'd spent a moment browsing the web sites then I'd have seen that one of the specialists was selling the item at half the price of the other. £47 versus £23. So if anyones swapping the Cats or doing a decat, they "should" purchase the large "Decat Securing Clamp" from Dom at TVR Power.
Glad you spotted the HUGE ! ! ! ! price difference that I mentioned in my recent post. (I'm sure that price should be for a pair of them). But I'm still too wound up to make a phone call to them. Just to add........ Always browse the Specialists Web Sites to get the best price. There can be some "Huge" price differences. I paid double the price for the identical part when If I'd spent a moment browsing the web sites then I'd have seen that one of the specialists was selling the item at half the price of the other. £47 versus £23. So if anyones swapping the Cats or doing a decat, they "should" purchase the large "Decat Securing Clamp" from Dom at TVR Power.
Edited by Jim Green on Friday 10th April 03:04
Do you think that by doing anything to change the running of the engine that it will cause the misfire to go away; plugs, wires, throttles etc for it only to return a short while later? Even changing petrol brands seems to cure mine for a while.
Could it be that in changing any of the above that the ECU "learns" a new setting, but a short while later some inherent fault causes it to return itself back to some "default" setting that is far from optimum?
just a thought...
Could it be that in changing any of the above that the ECU "learns" a new setting, but a short while later some inherent fault causes it to return itself back to some "default" setting that is far from optimum?
just a thought...
In the diag software on the 4th page there is a box for "warm up timer" and i wondered if this had any thing to do with it. On cold start up and hot running it just says ok so i presume this is not and issue. In Grahams sag manual, when connected to his car it says "no control" in the box.
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