16 replies to this topic

[minimilo25]

Good Morning,

 

My 1989 998cc engine mini will not start (the car has a standard HS4 carb).

 

This is long saga.  A few weeks ago I had a petrol leak between the float bowl and the jet, basically the seal had failed.  I took the carb off and resealed it using a repair kit.  Refitted the carb etc.  Went to start the car and it would not start

 

In my wisdom I thought there be some crap in the jet and bought a new jet and fitted it.  Again would not start

 

I then took out a spark plug after lots of cranking and it was dry.  I checked float bowl and it was full of petrol.  I have checked/refilled the dashpot.

 

by the way - There is a spark at the plugs so I know the ignition is ok.

 

Any help would be appreciated!

 

Cheers

  

[jime17]

Pour a dash of fuel down the carb throat then turn it over and see if it fires briefly. If it does you know it's a fuel delivery problem.

Just a dash though. Like a small bottle cap full.

[richmondclassicsnorthwales]

Did you make sure that the remnants of the old rubber gasket were all removed when refitting the new jet ?

 

What can happen is when you remove the old jet with fixed feed, the old rubber can disintegrate, and leave bits behind. When refitting the new jet, you could have wound in a little bit of old rubber into the delivery tube.

 

Are you absolutely sure you did remove all the crud when refitting the new jet ? 

[minimilo25]

Evening,

 

Pour a dash of fuel down the carb throat then turn it over and see if it fires briefly. If it does you know it's a fuel delivery problem.

Just a dash though. Like a small bottle cap full.

 

 

Tried that and it is not firing.....

 

 

Did you make sure that the remnants of the old rubber gasket were all removed when refitting the new jet ?

 

What can happen is when you remove the old jet with fixed feed, the old rubber can disintegrate, and leave bits behind. When refitting the new jet, you could have wound in a little bit of old rubber into the delivery tube.

 

Are you absolutely sure you did remove all the crud when refitting the new jet ? 

 

 

The seal was not disintegrated originally. It now has a new jet and therefore a new delivery tube. 

 

Cheers.

[cal844]

Check the pump is supplying fuel, are you getting a strong spark? How old is the fuel?

[TheFabMini]

hmmm doesnt sound good...

how long ago and how well was it running before the petrol leak?

 

if youve got spark and we know you have fuel going in.. then all thats left is compression and timing but from my experience even when timing is wrong you still get the odd pop and bang through the exhaust or inlet manifold when it sparks at the wrong point...

[minimilo25]

The float bowl is filling and the fuel is new enough. It was running pretty well before all this happened!

[TheFabMini]

The float bowl is filling and the fuel is new enough. It was running pretty well before all this happened!

Tried spraying some brake cleaner or anything flammable down the air intake??

[minimilo25]

 

The float bowl is filling and the fuel is new enough. It was running pretty well before all this happened!

Tried spraying some brake cleaner or anything flammable down the air intake??

 

 

Yes, a small amount of petrol.

[TheFabMini]

The float bowl is filling and the fuel is new enough. It was running pretty well before all this happened!

Tried spraying some brake cleaner or anything flammable down the air intake??

Yes, a small amount of petrol.

Maybe try something more vapoury like brake cleaner being sprayed a little when cranking the engine.. bit risky if it fires back through the inlet but I’d give it a go...
Apart from that I’m stumped... if it’s 100% got spark and you’re giving it a fuel source then it should go...
Does it sound like it’s got compression when turning the engine?
If you don’t have a compression tester there’s a few non scientific ways of checking if the engine has some sort of compression. Finger over a spark plug hole and see if you feel your finger being pushed off.
Other than that... no idea

[viz139]

If the engine was starting ok before you removed the carb then just concentrate on the carb. Remove the dashpot and piston and using a straw or tube blow down through the jet, you should hear bubbles in the float chamber . This will confirm that the tube is clear and that you have fuel in the float chamber. If this is ok chances are the mixture is too lean, check that the carb is mounted flush and tight and the breather hose is fitted properly so that there are no air leaks.If you have moved the mixture screw reset it it by bringing  the jet flush with the bridge and than turning it downwards two complete turns.Refit the piston and dashpot and by putting your finger in the inlet make sure it moves up and down freely. Put oil in the dashpot. Check that the choke is operating freely. 

Using full choke try start the engine.

[minimilo25]

So I blew through the jet into and I could hear the fuel bubbling in the float bowl. Tried starting, no joy.  Then I checked the plugs and they were wet, so all good.  Went back and adjusted the mixture as described above.  Thought I would try starting it again, still not starting. Checked the spark on the plugs, all good.  Cleaned up the plugs and went to start it again, guess what it did not start... Packed my tools away and gave up in frustration and thought I will be calling the local garage Monday.

 

Once I had sat down and thought rationally about it I decided to buy a new set of spark plugs (on Amazon - Prime delivery) so they turned up today.  I popped them in and she fired up first turn of the key!! Very strange, the car was running fine up to the petrol leak.  Anyway all good now.

 

Cheers everyone.

[cal844]

I'd be looking at your timing and choke settings.

Was the spark a strong spark

[minimilo25]

I'd be looking at your timing and choke settings.

Was the spark a strong spark

No need it is running really well and starting fine. 

[cal844]

I'd be looking at your timing and choke settings.

Was the spark a strong spark

No need it is running really well and starting fine.

Will it start good from cold ?