Plugs & leads

[cookie79]

Any help with annoying issue I have would be much appreciated

Under acceleration the car stutters in a split second & then bangs back into life, I went down the route of thinking it was a fuel related issue due to it just failing MOT with a leaking fuel pump, several fuel pump changes later & no improvement. Got talking to mechanic who suggested it may not be fuel but spark plug issue, so I found a old set of plugs & put them in & the problem seemed to improve, so I thought that's it then, ordered a new set of w5dpo's from euro car parts put them in & the issue was worse than ever, so I thought maybe HT leads, I've owned car for 17yrs & cant remember ever changing leads, bought a set from gsf put them on & problem still persisted, the best I can get car running is old plugs & old leads but still occasionally will have problem. Confused as thought a new combo of leads & plugs should at least make the issue no worse than before? I've attached a photo of old & new plugs they do differ in appearance but are both stamped w5dpo? Is it possible eurocarparts sell cheapy maybe fake items?
Again any help always appreciated

[PeteG40]

try changing the dizzy cap and rotor arm. and your coil.

I'd bet its your coil, but changing all three will mean your igniton system is pretty much all new and there's only the hall sender in the dizzy that may be at fault ignition wise

[samg40]

I've just had a similar problem in that under constant load/throttle it would start to bog down and try to cut out. If I floored it the car would pick up and be ok until you went to part throttle again. If left idleing it would cut out.

I changed the leads with a slight improvement but after changing the coil it has sorted it I believe, I've not taken it out yet as its SORN at the moment. I've gone through several coils over the years, and they've all failed slightly differently.

[cookie79]

Thanks, I hadn't thought about the coil, the dizzy rotor arm & dizzy cap are pretty new, replaced when rebuilt about 3K ago, so as you say if I get a new coil then it's all covered really.
Thanks again for the help.