Guys,

I finally have my Ute back with an A15 with Twin Su's and a 30/70 cam. It runs brillantly except for an annoying problem at around 100-110km/hr. At this speed when you hold the accelerator constant, about every 10 seconds or so you can feel a slight 'miss' and the car holds back. Sort of like driving into a head wind.

I was thinking that maybe the fuel pump may be struggling to keep up?? It is the stock 1200 one. Should I change over to something a little bigger (180B or Bluebird??), considering that I am running an A15 with Twin Su's??? Any ideas.

regards,

Daz

I doubt if it is the fuel pump, or you'd notice it more during acceleration, and would be worse at higher speeds.

It sounds as if it may be running lean (hesitates, misses) at that certain spot.

It also could be an ignition problem.

Are you running electronic ign?
It may be the spark plugs not the right rating...take the plugs out and have a look what colour they are. they should be ligh brown in colour.
If they are black and wet looking the mixture is too rich, white in colour too lean.

Guys,

Thanks for this. I looked at the spark plugs and they are a little white. It maybe running a little lean. I have taken the jet screws out by 1/4 turn each. Will see how this goes.
Thanks for the help.

Daz