1.2 misfire

[gitters27]

I’m having big issues with misfire on my 1.6 8V on twin 40s.
timing all good,carbs all good,fitted new coil/plugs/leads/roter and cap and still misfire.
i have ordered an ignition control module that’s in the dizzy to try next.
im starting to wonder if I have a bad earth? Where are the earth points because I can’t see one from the engine to body or gearbox to body.
compression at 190 on all 4 cylinders so all good on that.
purchased a second hand distributor but car wouldn’t even start with that on 🤦🏻*♂️.
please help

[gitters27]

Sorry forgot to mention the car was a 1.2 carb so using that ignition set up

[torquey]

I dont think it would be earth related what pump are you running. ,

[gitters27]

Facet red top at 3 psi

[torquey]

Right what did you set the timing at.?

[gitters27]

If you give it the beans/even to 7 grand it’s fine so I’m pretty sure it’s not a fuel issue

[torquey]

Strange pal. So its low down the misfire starts? Does it miss on idle?

[gitters27]

Cam is set to 105 degrees,crank 10.
Had it rolling roaded and it pulled like a train,had a slight miss low end but it’s getting worse and worse,sat cruising is horrendous.Even checked head gasket all ok

[gitters27]

Yeah misses on idle but not badly,Rev it up to 3 to 3 1/2 it goes

[torquey]

That was my next question head gasket..

[gitters27]

Iv played with the timing advancing and retarding makes no difference on misfire just power delivery

[gitters27]

It’s only done 150 mile since head gasket was changed

[torquey]

What fuel are you using? Are you using the 1.6 dizzy or 1.2?

[gitters27]

Super unleaded fuel and 1.2 dizzy set up

[gitters27]

I was using unleaded but had pinking no matter what I did with timing,changed to super unleaded and pinking stopped

[torquey]

I've heard the 1.4sr dizzy set up is the one to use with 40s. Dont know how true that is.

[gitters27]

Yeah iv used that set up before but used this set up years ago on another one with no issues

[torquey]

Right maybe something internal then could be the issue..

[gitters27]

I can’t see it’s that because I have good compression,cylinder head was flowed/new valves seals and guides/skimmed,all work carried out by reputable company,I have no air leaks on intake manifold

[gitters27]

Hopefully ignition module will make a difference

[torquey]

Hope so pal. Sounds like you have a good engine to start with. Hopefully something minor.

[gitters27]

She pulled 135bhp on the rollers,Dave Bogg who rolling roaded it commented on how well it pulled for a 1.6 8v

[torquey]

That's good power bet it goes well.

[gitters27]

It does once it’s past the misfire ;-)

[mowgli]

Are you using the black screw on dizzy with the advance retard diaphragm?