TD5 90 Chipped... Juddering at about 70mph

If the tuneit is the plug in type then try unpluging it and drive without it for a while, the tuneit only adjusts the injector pulse width, so is not concerned with tubo boost, depending on which tunit you have you could ty to adjust the potentiometer, to back it off a bit. Before I bought a tuning box I considered the tuneit unit but after some enquries of the manufacture decided against it. This was a pesonal opinion but I got the impession that it was not as sophisticated as the dastek unit, sure the dastek is more expensive but I have after 6 months of use had no downside to the unit.

Hope this helps

In message , Jon writes

It could be any number of things totally unrelated to you Tunit device.

Overboosting can cause this. The ECU senses and over boost and cuts the fuel. Duff sensor or split in hose on waste gate valve.

Oil in wiring loom can cause this, as can throttle pot, air flow meter....the list goes on.

Unplug the Tunit first and try without.

OK, thanks for your replies so far.

I unplugged the chip and all is fine (appart from its slower!). So I guess it's probably the chip?

I found the adjuster settings after speaking to Tunit (it was set at the half way stage). I dropped it to the "lowest" setting and the problem is still apparent, just at a different speed.

I then increased to the "highest" setting and again, the problem is still present, again at about 70mph.

Moving the adjustment just seems to alter where the power comes in and thus where it judders, when its set at its "lowest" position, the power surge doesnt come in until later on up the rev range, when its set to "maximum", the power band seems apparent almost from tickover.

Does this shed anymore light on the issue and a solution?

Thanks Jon

On Wed, 19 Apr 2006 06:15:22 GMT, "Dad" scribbled the following nonsense:

dastek, h'mm vowed never to have anything to do with them when their sales guy tried selling me chip for my 200TDi Disco at the Heritage Run. Repeatedly told them it was a 200 TDi..... They only got the hint when I took the vehicle to their show stand because i told them I didn't know where to fit such a chip to my engine......

Throw the box in the bin and bring the car to me for a proper chip ;-)

Marc,

What sort of chips to you use, would I need a bigger intercooler (its standard at the moment)? AND what sort of cash are we talking?

I guess you wont be in Yorkshire either??

Jon

No you would not need a bigger intercooler . TD5 intercooler is pretty good.

I am based in Kent but my maps are born and bread in Yorkshire so you are lucky there.

Mail me for more info