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?fuel starvation on 26VA
Jon, connect the condensor wire to the connector that goes from the coil to the distributor (low tension that is!), and earth the body of the condensor to a convenient earthing point -- in my case between the coil securing strap and the coil. The earthing tag on the condensor should slide under the strap. I ran mine in this condition for a couple of weeks until I replaced the official condensor.
Don't know whether it is relevant, but I have just ahd a similar problem with FG. Stopped at the garage to fill up this morning after a fast run. The little car went 500 yards up the road and stopped. would it restart? Would it b*gg*ry! Carb feed was vapour locked.
Understood Dave.
David - does the ethanol result in greater vaporisation? How long did you have to wait?
Hi Jon

I use one of these to check capacitance

AIMO M320 Digital Multimeter DMM Frequency Capacitance Meter Auto Range B1C9


Hi, Jon.

About ten minutes. Usual checks, diagnose problem, find spanners from under the seat, slacken the union to the carb. Get fuel to flow and back going again. Put everything away and drive off.

Don't know about ethanol evaporation, but it was quite warm today. And the exhaust manifold is not far away from the fuel line.

Remember that FG is an RP saloon, so rear tank and fuel pump.

I had fuel feed problems on my car which is gravity feed to an updraught carburetor. It was caused by the in-line filter which restricted the flow too much. With the filter removed I've had no more problems.
Gravity feed to a sidedraught is going to be more sensitive to flow restriction.
Jim - I've got a socking great/oversize plastic/paper concertina disposable one for that reason. Would you agree that the 5 minute pint fill mentioned earlier in the thread is a suitable test? I suppose I can compare the two flows with and without.
Even if it turns out to be a distributor based problem, it is worth knowing the parameters for that filter...
Hello again JonE

My quick calculations show that 5 minutes per pint (1.5 gallons per hour) would be sufficient (or a bit more than sufficient) flow rate for a 17 bhp A7 engine running flat out. It would correspond to 33 MPG at 50 MPH.

Back to condensers, I wrote a piece a few years ago called "Capacitors (Condensers), How they're made and why they fail". This gives more detail if you are interested. You can find it on the Dorset A7 club website under Technical Pages, Electrics+Ignition.

Cheers, John Cornforth
Hi John

I've used your article several times recently.  It is very very helpful.  Thank you.

I'm using the old DS4 distributor on my RK and have 2 condensers of the correct shape. One shows 0.5 microfarad but the spare shows 1.4.  Is this within the bounds of acceptability or should I be looking to hack it about and fit a more modern condenser (say from a DK4 inside it) Thus preserving the look of the dizzy?


Condenser value isn't that critical in my experience, somewhere between 0.25 and 0.40 microfarad is acceptable.  A reading of 1.4 microfarads is way off and suggests a faulty component.

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