S1 Not Running / Misfire

[mylesw]

Hello,

So I got in my car for a drive last weekend and when the car fired up it was misfiring badly with a lot of shake. I decided not to take it out and have been trouble shooting since. After the first run the car now does not really run anymore, although I do get the occasional short burst. It's strange as when I parked it a few weeks earlier it was running fine. The car has a mallory unilite distributor (electronic), an MSD Blaster 2 coil and ballast resistor. Here is what I have done so far

1. Cleaned fuel filter, tested fuel pump which is delivering 1.2 l/min @ 6psi
2. Checked float bowl valves which are moving freely
3. Checked compression which is +/- 120 psi on each cylinder (cold obviously)
4. Checked spark to each cylinder
5. Changed coil to a lucas type and bypassed the resistor
6. Changed distributor cap
7. Plugs are wet when removed

Plan to change the plugs as soon as the new ones arrive in the post. Only thing not changed is the rotor/shutter and the unilite sensor itself. These parts are quite hard to get in the UK hence why I haven't replaced these yet. However, given that there is a spark at each plug I'm not convinced (yet) these are faulty.

Any suggestions what to try next or what the cause of this could be?

Thanks

Myles

[rswaffie]

Hi,
6psi is too high, it should not be more than 3. Is it a new solid state in-tank pump from SNG? If so, you probably need a regulator to get it back to spec.
When you say plugs are ‘wet’, is it fuel or oil on them?
The cold compression figures seem low - on my 9-1 engine they were around 185 from memory.
Have you confirmed the timing settings and also that the dizzy is not loose.
From another post re. Mallory-“ Without a ballast resistor, the optical trigger unit will fail prematurely.”

[mylesw]

Thanks Richard. Plugs are wet with fuel. Fuel pump is a few years old and I converted to a pump which isn't in the tank but the R/H wheel arch like a 4.2. I do have a brand new SU pump so could replace that if necessary.

Looking back at the last compression test back in 2017 pressures were at ~180 psi cold. What would cause them all to read 120 psi? Faulty gauge?

[mylesw]

Fitted the new plugs this morning, and took the opportunity to check/tighten up all the connections on the ignition system. Car is now running fine - may have been the plugs but more likely a loose connection in the ignition I expect. Thanks for your help and suggestions on this.

Myles