Running Problem - Its back again!
Turbo Mini Forums

I've got a problem which is causing me to tear my hair out and would be grateful for some help!

After finally finishing my turbo build I was amazed when the engine fired immediately (once I'd remembered to put some fuel in it...) but since then things have gone backwards.

The engine starts easily and will run for 10-20 seconds and then dies - after that nothing. It appears to be a fuel problem (I've still got sparks) but I can't trace it. There's definately fuel in the float chamber, and there's fuel feed to the carb, but nothing happens.

My first thought was some crap in the fuel so I stripped the carb to clean it - didn't find anything suspicious so put it back together but the problem is still there.

If I leave it for half an hour it fires up ok but then dies again.

Has anyone had a similar problem? Is there something obvious I've missed? Any ideas/suggestions would be gratefully received!

Edited by mike_jenkins on 11th Jun, 2011.

pull the daspot off and turn the pump on, check fuel dosent overflow out of the jet so the engine floods.

if it does you need to check the fuel pressire and the float valve.

this could be a sticking float valve ?
also
make sure you have the carb piped up correctley!

and as joe C states

Ok,

Have you replaced the gasket between the carb and plenum? some dont have have the holes in them to the dasput.

also, its worth pulling out the choke assy to check the seals, if they are knackered they can cause issues.

Check that the fuel tank is vented properly. Mine used to tick over for around 5 minutes and then cut out. It was down to the tank becoming pressurised and not allowing fuel to the carb.

I couldn't fund anything wrong at all to cause the problem I had so eventually bit the bullet and did a complete stripdown and rebuild of the fuel system from tank to carb (and replaced the carb itself).

I was very relieved when it started first time after the rework and everything was fine until last night...

I was warming it up when it died on me - didn't think it was too much of an issue and it appeared I was right, there was no fuel in the tank. The problems started when i refilled the tank and tried to start it again... nothing.

My first thought was maybe an airlock somewhere, so I pulled the fuel pipe from the carb and ran the pump for a while (there was a small slug of air in the pipe but nothing major) and once i was happy that it was just fuel connected it back up - still nothing.

I'd be grateful for any ideas on what the cause is and what I can try to resolve it - the way its going another season will be over before the car even gets to the track.

Edited by mike_jenkins on 11th Jun, 2011.

first you need to be fitting a pressure gauge to the carb this will reveal all
keep us posted

faulty pressure reg especially if its old, duffed fuel pump may be?

Is it a turbo carb with the lean-off pipe? any split in this will cause all knds of problems.

Is there definately fuel in the float bowl since it was emptied?

As a long shot the needle valve may be jammed shut or the needle may be stuck in the jet.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph