Help! 911SC

[aquaregia]

My 911sc was shipped out to Dubai and since arriving here the car has not been happy, maybe she misses the snow rain and cold! Issues have been cold start problems back firing and generally running poorly. Spluttering and loss of power under load. I assume the 45 plus degree heat in summer does not help, but in winter its a nice 25 degress and still issues. So far I have changed the WUR had new leads, distributor cap, rotor arm. New injectors with new rubber seals. New coil, new fuel pump, new pressure regulator. This resolved the backfire issue but then the car started hunting, however when I remove the oil filler cap the car idles perfectly. The fuel pressure is ok and the lines hold the pressure ok when the engine is switched off. I have searched for a vaccuum leak but nothing as yet. I have decided the next route is to replace the inlet manifold hoses and the whole vaccuum system hoses. Before considering the fuel distributor. Has anyone here had any similar problems. The air box has the pop off valve fitted there are no visible cracks. Any advice would be welcome. I am beginning to dislike CIS! My TVR is now proving to be more reliable!

[Merritt]

Different grade fuel??? I have no idea what they use in Dubai but you may need the ignition timing adjusted??

Steve

[BliarOut]

Check what grade of plugs are recommended at those temperatures. Also you'll probably need the mixture altering to cope with the less dense air.

Removing the oil filler cap to cure the idle is a new one on me, it does point to a build up of pressure somewhere internally

[aquaregia]

The octane rating here is 95 and 98 same as UK I assume its similar to the summer blend in the uk, not sure about what plugs I should use, where can I find out. Re build up of pressure I can only think that the rings are worn but the engine had a full rebuild 30,000Km ago and during my investigation I did pressure test the cylinders all roughly the same. Not the best test but implies even wear! I do notice now in winter that the car runs better at the lower temperature,on warmer days the problem gets worse, obviously the denser air helps. re mixture what would you advice for higher temps? Thanks for the advice.

[BliarOut]

You'd probably need someone to remap it to suit....

Have you got the manual?

[ED965]

Sounds to be like a fuel/induction issue without a shadow of a doubt.

[henry-f]

I suspect you have corrosion in the fuel injection system. New warm up regulator, fuel distribution head & injectors. The fuel distribution head needs to be replaced, if you take them apart there are little filters that look as though they can just be cleaned out and replaced but it never seems to work. All the items need to be replaced in 1 go wth new.

Take the tank out and flush it as well as the fuel lines.

Obviously very hard on a car of that age so ust a guess.

Henry

[aquaregia]

Thanks chaps will get to work this weekend........

[northeast]

Try a search on Pelican Parts, tons of good advice.
http://forums.pelicanparts.com/showth