my xk150 3.4 started running rough last season. it was intermittent, usually starting as I hit a hill or put it under load in 4th. This was unpredictable and only happened once or twice every combined 50 miles or so. This spring I put it in for a tuneup and oil change and my mechanis said everything looked good it only needed plugs and minor tweaking. Since getting it back this condition has worsened. It is more frequent, it occurs in other gears, and now it is more severe actually shutting the engine down. It will restart without a problem and when it is not occurring the car runs great.
I changed out the fuel pump, drained the tank and checked it for debris (none and very clean) put in a new sludge screen/plug, blew out fuel lines etc. My various service resources and myself thought it was a fuel supply issue. None of this has helped.
Is this elecrical? Are the carbs going (gone)? Any one out there have experience on this it is driving me nuts and the season is here. Help!

Submitted by hannondon@hotm… on Wed, 06/09/2004 - 15:49

I had a similar experense a while back and the problem was bizzare. I had developed a minute crack in the flexible (rubber) fuel line between the tank and the fuel pump. Occasionally it would suck air instead of gas (sputtering and dying from fuel starvation) Replacing the fuel line cleared it up. Good luck !

Don & Nora XK 140

Submitted by tgman@ix.netcom.com on Wed, 06/09/2004 - 11:28

You've done the plugs and fuel thing so here's a couple of other things to look at; coil, plug wires and wire ends, distributor cap, rotor and point contacts. Coil and plug wires are most frequent failures, but things like the carbon contact in the cap can also increase firing voltages to the point that the coil can't generate enough voltage.

Submitted by rmurray@turfpr… on Wed, 06/09/2004 - 11:08

Thanks for reply. I am told it could be the coil but if it was it would not restart immediately as well as it does? It is suggested I test some of the wires, coil, main distributor, etc Comments? Thanks

xkmeister