69 mgbgt rough running

[poolystan]

Hi all, Whilst out on a run yesterday the "B", after about 15 miles of great driving developed a lot of hesitation whilst accelerating. I pulled over , lifted the bonnet and revved the car up, it revved ok with no hesitation whatsoever. I drove off again and it seems the engine did not want to accelerate under load and felt like it was about to cut out. I managed to limp home by using very gentle movements of the throttle. The weather was 26 degrees the engine temperature was normal, I have lumenition magnatronic electronic ignition fitted and K&N filters. Any ideas what is going on ? I have sent away for a new dizzy cap and a set of silicone leads as a precautionary measure just in case it's that .

[mr rusty]

It could be a fuel starvation problem- take it out, when it starts to play up pull over and whip the fuel cap off and listen for a big inrush of air and then normal running. If this occurs then your filler cap breather is probably blocked. With regard to ignition, avoid Lucas branded stuff like the plague- it's awful, made in chinese slave factories to a dreadful quality.If your rotor arm has a rivet holding the brass bit on then it's one of those and throw it as far as you can.......go to http://distributordoctor.com/red-rotor-arms.html and buy one of theirs, superb original 60's/70's quality.