Help. I’m going crazy trying to identify the reason for a misfire on a classic A-Series engine (the type you find on a classic British mini).
On the ramp the car runs fine. Revs freely. No misfire. Idles fine. Popped into gear on the ramp and “driven” off the ground it runs fine. Through all gears up to 60mph no probs.
But. Put car on the road and it immediately misfires, pops and splutters and even cuts out. I’m assuming the difference is that it’s now under load and on the ramp it is not.
so far I have checked and changed out the following:
Fuel pump and line, manifold gasket, ignition leads, plugs, it’s electronic ignition so no points to change, checked carburettor and float bowl, sprayed it with fuel spray to see if there’s an intake leak (none found).
So I can’t find a fuel starvation issue. I can’t find a sparking issue. I can’t find an intake issue.
What next???
Please answer all the questions in the first paragraph for help.
On the ignition side, Use a spark tester on each ignition lead to confirm that you're getting strong enough spark from the ignition coil to all 4 spark plugs.
Maybe replace the distributor cap and rotor if it hasn't been done already.
Also, check the ignition timing with a timing light
what is an "A-series"?
