Need help from the guru's

[BillC]

Hi all, in a past thread I talked about my XR8 missing. the suggestion was to put new spark plug leads. I put MSD leads on but the car is still missing. i am running NGK iridium plugs that have been in for about 20,000 Ks prior to these symptoms. The symptons are:

Starts fine, drives fine. Good economy (well what you would expect from an XR8)

But after a drive for about 30 minutes the car will miss. When I say miss it loses power for two or three short bursts. Its like the car hic ups. It does not feel like the leads are breaking down because I have felt this before. It mainly does it at low revs. Doing a U turn for example but not all the time and not necessarily turning. Then it might not do it again for another 30 minutes.

One thing I noticed when I tried to change the throttle position sensor with my mates Au 6. I pulled it out and when I put it back on I positioned it incorrectly and it gave the same hic up almost every time you drive off from a full stop. When I positioned it correctly it stopped doing it at take off but it has that same hic up every 30 minutes or so.

I am thinking I may have a dead spot on the TPS.

Could this give me those hic ups at a certain rev point ?

I would like to find one and swap it for a day to see if that is the problem before I go and buy on. I am not convinced this is the problem. I wish I knew somebody else with an XR8. Au 6 cylinders look the same but they have a different plug.

I took it to the local mechanic and of course he could find nothing wrong with it. It did not do it for him.

Any help or ideas would be appreciated