hesitating when cruising. MK2 8v KJET

[Stu-dub]

Ok, this is bothering me now.

Timings set to 6 degrees, mixture is 1.5% at idle, idle set by the book and sits at 950 headlights on, breather disconnected and plugged.
New plugs, leads, cap and arm.

When I'm on the motorway cruising at 60-65 it feels like it keeps hesitating. No misfire as the exhaust note doesnt change, if I put my foot down it pulls cleanly.

So I thought it was a tad retarded, so I advanced it very slightly, went for a drive. Seems to cruise better but if I'm at 65mph in 5th and put my foot to the floor I get pre-ignition, or pinking.

If I back the timing off ever so slightly it seems to cruise smoother but not as smooth and still pinks when I accelerate. I've done this several times and no matter how much or little I move the dizzy I can either have smooth cruise and smooth acceleration from low speed so long as you don't push to quickly on the throttle and pinking under load when putting foot down quite far as if overtaking, or hardly any pinking under load but a hesitant annoying cruising speed.

I'm at a loss.

Any ideas?

Stu

[Horney]

What fuel you running? Should really be Super.

nick

[Stu-dub]

Yep Super Unleaded, albeit Tescos as thats all I could get last time.

[Horney]

Tescos is good stuff so that should be OK. I would suggest getting a garage to have a look.

nick

[rubjonny]

check your injector spray pattern/flow rates also get a fuel pressure test done.  I'd be tempted to tweak the co up to 2%, 16vs like to run at that, pretty much same setup as the 8v

[Stu-dub]

Does anyone know of a garage that could sort it out for me? Flow rates, spray patterns and pressure testing isn't something I can do with my knowledge.

I'm Herts in case theres someone close.

Cheers,
Stu.

(This is making me think 16v and bike carbs a bit more seriously)