bad idle or overheating after stopping?

[LeRoiDeLaRue]

Mine does it too ... is there no fix, such as putting some slots in the bonnet, like TVR did with the Chim and after market to Griff?

[Herman]

Mine does it too ... is there no fix, such as putting some slots in the bonnet, like TVR did with the Chim and after market to Griff?

Not really.

[LeRoiDeLaRue]

Hmmm.... I had a problem on acceleration twice on return home the other day. I spoke to chap who supplied a replacement engine to a former owner and he identified a possible dodgy fuel pressure switch as maybe not responding swiftly enough on demand ... maybe it is linked?

[Herman]

Hmmm.... I had a problem on acceleration twice on return home the other day. I spoke to chap who supplied a replacement engine to a former owner and he identified a possible dodgy fuel pressure switch as maybe not responding swiftly enough on demand ... maybe it is linked?

If it is something else (or also happens when cold) it might be pump, sensor, dodgy COP or plug.

If they're all OK and it still happens it is most likely vapour in the fuel line due to heat build up. TADTS

[WNJ516]

Would be interesting to know what fuel pressure the rail is at, and what temp the fuel rail is when this rough idle occurs. What temp does petrol boil at, to cause this vapourisation. I don't presently suffer with it but should it occur will try and take those measurements.

[Cribbit]

Suffered quite badly from this today. Did an hours drive, stopped for an hour and then had really lumpy idle. Drove for 20 mins, stopped for 20 and same again. Then drove for an hour again and stopped for 10 mins and it was fine. Whilst I do quite like the car's shake and the lumpy low idle noise it makes and the burbling when you bring the revs up with no load it's probably not generally good for the car. It does seem quite random as to when it does it, and it's more frequent since I had the kenne bell heater bolted to the top of the engine. I have no insulation under the bonnet, and plan to fit some vents if I ever get round to having some body work mods done, so will be interesting to see if this helps.

[AndyG]

Try running without the under engine plastic tray.

I removed mine years ago mainly to aid the view of any liquid leaks.

I understand it was fitted for something to do with high speed running. As I rarely exceed the NLS by much for any length of time I have not had any problems.

Without it it would allow the air from the rads escape.

[Julianp]

This sounds like fuel vaporization, which affects the fuel/air mixture and can cause the engine to misfire and idle roughly. I used to get this periodically with my (standard) 260 in heavy traffic in Paris during hot weather. On a couple of occasions it triggered the check engine warning light and I had to reset the codes, but it always fixed itself once the car had cooled down.
Julian.