engine rev issues over 4k

[MGB3405]

Hi

I'm still fairly new to all this.

At the week end under hard acceleration I was unable to rev past 4k in second and third it almost felt like a rev limiter, quick check of leads and one was loose (at Dizzy), once tightened all was fine.

Again tonight same problem but no loose leads tick over fine and pulls like a train up to 4k any thoughts......

it's a 4.0 pre serp (not sure of relevance)

[ITVRI]

I would check for fault codes with a borrowed code reader or even better buy a lead from blitz racing (see TVR classified) Copy rover gauge to a laptop to do an analysis. Rover gauge comes with a fault coder reader inbuilt. It also has a logger that you could analyse.
This may show up the fault causing issue.
You mentioned it does not miss until 4000 and from there it acts like a rev limiter and cuts out completely. That would tend to rule out basic ignition issues in my mind except maybe the coil.

[Chilliman]

Check the inlet hose in the nose, from the filter back through into the engine bay. If it's squishy it could be collapsing. Maybe. There could be a whole host of other reasons but this one is easy to eliminate as a possible cause.

[FlipFlopGriff]

Ignition amp, coil, king lead. Could be lots of things.
FFG

[MGB3405]

Thanks for all the advice

Tonights update re-bedded all leads at dizzy and went for a drive all sorted (couple loose again), but popped out a short while later same fault, fiddled with leads all good again.

The leads and dizzy look pretty good but coil is ancient, so coil and king lead change and see where we go... then look at filter

ITVRI if I buy the lead is Rover gauge pretty idiot proof?

[ITVRI]

Rover gauge is plug and play.
It is what you gleam from the information displayed thats not idiot proof. I found by looking at the information displayed it give me a clue in which direction where to look or help rule out potential issues. Just another tool in the bag.

I also have an electronic infra red temperature reader that I used recently to measure the heat output of each cylinder and quickly diagnose a faulty lead extender. This may also help you to see which cylinders are not firing.
Cheers Warrick.