brick wall and the change up lights.

[rick111s]

this has happened a couple of times so i thought i would post and ask advice please.

it's happened in 2nd and 3rd.
full throttle, first change up light comes on then wack feels like you have hit a brick wall or the rev limiter. the car seems to die. both the second and third lights work so i'm not being stupid.

is this normal? what is it?

thanks for any advice as i'm getting worried...

[TSS]

If it’s at about 6000 RPM then it’s a common problem. Something to do with the ECU getting erroneous readings and cutting the fuel supply (no doubt somebody here can give you a better explanation).

It can sometimes be cured/improved by adjusting the throttle pots (a dealer job). Alternatively you may need a different ECU chip. My Tuscan used to do this until they changed the chip.

[rick111s]

thanks for that.

any idea on costs? the car is still under both tvr (engine) and dream machine warranty. is this a warranty job or just live with it or pay for it myself?

rick

[nelly1]

Rick

I had exactly the same syptoms as yourself, and though it must be something serious!

The car went in for a 6,000 mile (standard - not tappet) service.
The usual stuff was done, but new plugs and throttle pot adjustment transformed the car

If a service isn't imminent, get it done on warranty.

Neill

>> Edited by nelly1 on Friday 28th October 10:26

[Mr Freefall]

rick111s said:

this has happened a couple of times so i thought i would post and ask advice please. it's happened in 2nd and 3rd. full throttle, first change up light comes on then wack feels like you have hit a brick wall or the rev limiter. the car seems to die. both the second and third lights work so i'm not being stupid. is this normal? what is it? thanks for any advice as i'm getting worried...

It was cured by a de-throttle chip that TVR would supply. Its the throttle bodies that are warn. The casing is ally and there was a brass needle that holds the it in place to the ally casing. Over time thii wear, and the problem is that the ECU reads over 100% of fuel to the system from pod 1 as the wear causes vibration and and error to the ECU, then automatically sets the mixture to very lean, hence the brick wall.

Now, the best thing to do is update the throttle bodies with the roller ball type that stop the wear in the needle. TVR Power do the conversion, I got mine done under warrenty with my engine build. Dreadnought do some on a PX basis I think.

You can got for the de-throttle chip, but its just a quick fix really.

Mr F

[J_S_G]

Could be a number of things - starting off as simple as the HT leads, and working through the options like worn throttle bodies, etc.

If you have slightly stuttery running at constant revs (3000 seems to be a bad one for it), then it's likely to be the throttle bodies that are worn. Dreadnought and SFR both manufacture uprated versions that you can replace the existing ones with. If the only problem is just a brick wall at 6k RPM or so, I'd be more inclined to have it serviced first - new plugs, leads, and throttle pots set up.

As an aside, regarding the ECU... it's a "dThrottle" chip - it measures the delta (difference) of the throttle differently, rather than de-throttle (which'd mean it held back on the gas!) What (all of the) ECUs do is take readings to see the difference in throttle, figure out how to fuel the car accordingly, etc. Problem with worn throttle bodies, etc. is that it gives erroneous readings over very short time periods. The dThrottle chip takes readings over a slightly longer period (i.e. a greater delta), evening out the false readings. This does inherently mean that you have slightly less crisp throttle response, however.