Engine not running - can't figure it out

[James k]

Hi,
After covering over 2000 miles on its trip from Hastings to Inverness and back, my traveller broke down on the M25 just before Dartford!

I was stuck in a traffic jam in hot weather for about an hour when the engine suddenly sputtered to a halt and wouldn't restart. The oil pressure and water temp were fine but the fuel pump had been ticking frantically so I thought it had to be vaporisation. I managed to push it from the middle lane into the hard shoulder (not the nicest experience) and left it for half an hour to cool down as the whole engine bay was extremely hot.

After half an hour it still wouldn't start or rather it would but it ran like a single cylinder engine and sputtered to a halt. I checked the following:
Fuel: pump is delivering fuel properly.
Spark: there is a spark at the king lead and each of the plugs. I also tried swapping the coil as it was very hot.
Compression: reading 160-170 on all four.
Carb: piston is rising and falling as it should and the needle is clean.

After all these checks and the engine still not running, I had to have the AA tow the car back to Hastings. I've tried running the engine again and it seems to be only firing in cylinders 1 and 2 as removing those leads stops the engine where removing 3 or 4 makes no difference.

It may be worth noting that the day before, the air filter came off. I have no idea how but the stud holding it on suddenly sheared off. Also, I have electronic ignition so no points or condenser.

I'm rather out of ideas. Any suggestions?

Thanks,
James

[oliver90owner]

Have you put the plug leads on correctly? Everything (other than the timing) seems to have been checked out and is good.

[oliver90owner]

Return trip to Inverness from Hastings is far less than 2k miles - which route did you take?

[oliver90owner]

Have you put the plug leads on correctly? Everything (other than the timing) seems to have been checked out and is good.

[James k]

The plug leads are in the correct order. I've just had the manifold off to see if there was a blockage but it's all clear. I've also checked the valve clearances and seen that the valves are all operating correctly.

With regards to distance, I took a rather round about route and visited a lot of places each day.
It was the driving around whilst in the different stops that helped rack up the mileage.

[James k]

I've just put the manifold back on and it's started. It's now running on four but is still not running right. It's idling rough and intermittently misfiring.

Somehow taking the manifold and carb off changed it

[simmitc]

Checked that the jet is clear, and also its feed at the bottom of the float chamber. Not long ago, I had the rubber sealing washer start to break up and a little flap acted like a valve to briefly stop petrol flow to the jet.

[philthehill]

If you had vaporisation at the pump the engine could have pulled some muck into the carb jet when the fuel was low in the float chamber.
One quick way to clear the jet is to rev the engine and put the palm of your hand over the carb intake and usually the muck gets sucked into the engine so clearing the jet.
It appears very much like muck in the carb jet is your problem.
Phil

[oliver90owner]

Spray some oil around the intake area of the manifold while the engine is running. If the engine note changes, you have an air leak.

[James k]

Phil, looks like you were dead on. I tried the hand over the carb trick but it didn't seem to work. I then disconnected the jet from the float bowl and blasted lots of carb cleaner through it. I also cleaned out the float bowl which had quite a lot of dirt in it. After reassembling it ran perfectly! I just wish I'd thought to try that yesterday instead of having to be towed.

Given that the carb is generally quite dirty, the jet pipe looks very old and the rubber o-ring is partially disintegrated, I think it may be time to rebuild the carb. What do you reckon?

Thanks

[philthehill]

Me thinks that it is time to service /overhaul the carb.

[Dogsdad]

Nice to see a good result here.
Nothing worse than posts that simply stop and give no answer.
Well done you and Phil.

Richard M.

[pgp001]

I have just recently rebuilt the carb on my Traveller, it has made a world of difference to its general running and fuel economy.

I fitted a new throttle spindle and butterfly plate, new float needle valve, new main jet and needle, and a new dashpot spring.
It now ticks over much better than before, it was drawing some air in past the worn throttle spindle I think. Luckily the carb body was OK it was the brass spindle that had worn oval.

The new butterfly plate has a little relief valve in it now that was not on the original one, and I have noticed my "parp" seems to have all but gone on the over run, I can only think the little valve is the reason for that, any ideas anyone ?

Phil

[StillGotMy1stCar]

James, Such a shame your journey ended like that and unfortunately foxed the AA man with nowhere to plug his thing in to tell him whats wrong...
pgp001, The poppet valve on the butterfly is to reduce emissions. On overrun with the butterfly closed the mixture gets rich, the valve opens to lean out the mixture. The valve can wear and can cause idle problems, it can be soldered shut to get your “parp” back.
In effect the throttle isn't fully closing until near idle speed is reached and you only get the "parp" on a closed throttle.
I think that might explain it but welcome other thoughts.
Regards John.

[James k]

I've bought a rebuild kit and have started dismantling my carb. It's all rather filthy and forget about wiggling the spindle to feel the play, I can SEE through the gap! presumably this means I'll notice some improvement after rebuild.

I've already checked the new spindle in the carb and it has zero play so I won't need to rebush. I've also got various grits of wet and dry paper, some wire wool and aluminium polish to shine up the outside.

I'll let you know how it goes.

[philthehill]

James
Clean the body of the carb in cellulose thinners - it will come up like new but without the shine...….
Phil

[Nickol]

......and how can you make it shine????

[edd_barker]

You can spend hours polishing it up, but it will tarnish pretty darn quick in the air, undoing all your hard work.

You can buy chromed dashpot covers and mirror-finish heat shields if you desire a bit of bling.

Edd