Thread: Engine Problems - diagnosis help

Sounds like possibly points are burned or too far apart or ignition timing is out

As above, sounds like an ignition issue.

Check timing, points, replace condenser, distributor wiring and weights, coil wiring...

Could also be a fuel supply problem, such as an almost blocked strainer in the fuel tank, or a leaky valve in the fuel pump, or an air leak on the suction side of the pump. (or all of these)

John

Whip the air intake ducting off of the top of the carby. and with the engine off check for the operation and security of all the external linkages and the butterflys (round disc things that block the throat of the carby)

Open the choke all the way (the topmost of the 2 butterflys) lean back a bit and look down the carby, now snap open the accelerator linkage, the accelerator pump should stick a spray of fuel down the body of the carby and into the intake manifold.

If thats working start it up and watch whats happening in the throat of the carby. try a couple of sharp taps on the accelerator and watch whats happening then. then try a long slow opening and see what that does for you. Keep watching in the throat.

it might help to disconnect the vac advance which is a small line that runs from the bottom of the carby to the bottom side of the dizzy. blank it off on the carby side.

What do you thinks happening?

Having just finally got one of these running almost right (still runs on after turning the ignition off) I can point you at the areas that I have worked on.

1. Distributor, get some new points and condensor in there. I actually ended up getting a brand new replacement ditributor. I have seen them online for $110 + postage and they include new points, cap, rotor and vacuum advance, all of which would probably cost as much if you bought them seperately. I paid a little more for the distributor to get it straight away from a local supplier. As soon as the new distributor went on it ran much better.

2. New plugs and leads. Very easy to do and then you know where you are starting from.

3. Carburettor. If it is the Zenith carby then rebuild kits are available for them. The right rebuild kits include new throttle shafts and plate, idle mixture screw and needle and seats as well as all the gaskets. I actually ended up buying a new carby as they are still available but only because the float bowl on my old one had some cracks, not because I couldn't rebuild it. It took a lot of fiddling with float levels, recutting the thread on the idle mixture screw and getting timing and mixtures right before it ran properly whereas the old one rekitted ran pretty well straight away before I discovered the cracks. I believe the kits are also available for the older Solex carbs.

4. I had a leaking exhaust gasket. In fact one of the bolts was missing. New gaskets and new bolt and stud sets are available but you might need to make sure you get the new studs and bolts for the inlet as well as the exhaust as they are joined together.

5. Timing. Critical to get this right. A couple of degrees made the difference between the car idling correctly (once I had fixed the mixture screw) and just dying after a few seconds of idle.

Just putting a kit through the carbie and making sure it is right will answer the questions that Dave is asking and it is not that hard to do and not that expensive.

The rider on all that is that I am not a mechanic, I have just been working on mine for a while now since I bought it. Dave (Blknight) is a mechanic and knows a hell of a lot more than I do .

Tim.

One more thing I missed above - Fuel filter. Mine would die on steep hills until I cleaned this out and then later replaced it.

Tim.

Thanks for your help. I'll look into all your suggestions. I've got a feeling the Carb is my biggest problem.

it may not be but if the engine is running its an easy place to start and eyeball what is going wrong.

I've seen problems that you would have sworn were carby fuel issue problems (I agreed with the initial diagnosis and replaced the carb with a known good zenith) that turned out to be the coil breaking down.