More trouble with my Classic

5 of us all set for an early start and a day at the coast then ....

My Classic 1989 EFI failed to start, cranks,splutters every now and then, but will not fire up. Keep on cranking to the point that you think you will flatten the battery and give up, she then splutters and starts. Will then drive beautifully for the rest of the day. Next day same old problem .....

Replaced recently with genuine spares...
Coil,Leads,Plugs,Dizzy cap,Rotor,Reluctor coil,Amp,Earth lead and petrol pump

If you have any ideas we will all be most grateful

Hi, Had a problem not to unlike yours a while back,When started after a lot of cranking the engine would rev to about 1500 to 2000 then nearly stall.On mine it was the fire trap and breather pipes from that where blocked.A new fire trap and cleaned pipes solved it.

Thanks I will try that.

The fire trap, is that the metal cylinder on top of the rocker cover ?

I also forgot to mention that when I do get it started the engine runs at about 1100 in park or Neutral, but select a gear and it drops back to 600 until hot

Check the coolant temp sensor resistance with a multimeter. The resistance should be around 7k Ohms or so when cold and 200 Ohms when warm. Or just renew it (fairly cheap).

Does she start fine when engine is hot?

Thank's I will test the coolant temp sensor today.

Yes she starts and runs fine for the rest of the day, it's only when you leave her over night and try to start her the next day that this happens.

Thank's guy's

I have cleaned the flame guard and pipes, loads of gunge came out.

Then I checked the coolant sensor and it was full of green stuff, cleaned and sprayed with WD40.

Eventually she started, so I removed the hose between the MAF and filter to find the flapper and entrance covered in what looks like dried mud, cleaned the area with a cloth soaked in carb cleaner and re-started her spraying carb cleaner into the entrance. Flapper then shot right to the back with great clouds of smoke from the exhaust.

Ran fine for the rest of the day, so I will try a cold start tomorrow.

I think I will replace the coolant sensor as it looked as though coolant da leaked through to the connector at some time.

I will keep you informed....