Help...back firing, loss of power - NOW TRUELY PI$$ED

[Baldrick]

Hi all

I've just had the bus serviced and rolling roaded so that nothing can go wrong while we are on holiday...

Half way down from Kent to Devon the bus started back firing and losing power. I'm reduced to crawling up the slightest incline and when I put my foot down I can smell petrol in the cab.

There is no smoke that I can see and there were no ominous "bang" type noises...

Any ideas? It was very wet on the way down and I wondered if I have damp problems. Don't shoot me, but I've recently had an electronic ignition put on, could this be breaking down under heat?

Other than that anyone know a good mechanic in Kingsbridge Devon?

Looking for some good news here guys...I really don't want the trailer of shame home like I did two years ago

Thanks

Andy

 

[Gert Big T]

I had similar issues on a previous bus. It was a couple of things. One was the ignition leads coming loose from the spark plugs and distributor cap, the other problem was due to the small cam on the of the carb catching on the casing of the aftermarket alternator that was fitted, as this was causing the engine to only have half throttle, which in turn was making the engine struggle and over heat at speed, up hills etc. I ended up having to put a spacer on the carb to lift it higher and shave a mm or two of the alternator casing to let the small cam clear. :?:

 

[Baldrick]

Thanks. I'm still a bit suspicious of the electronic ignition as that is the only thing that has changed.

I think it will end up being a call to the RAC.

Sent from my HTC One X using Tapatalk 2

 

[Kombi zombie]

Not in Kingsbridge but in Plymouth give these guys a call:
Quayside VW.
Unit 3, Cattedown Road
Plymouth
PL4 0RW
Tel:
01752 268795

These guys look after my bus.

Cheers,
Rob.

 

[Baldrick]

Not in Kingsbridge but in Plymouth give these guys a call:
Quayside VW.
Unit 3, Cattedown Road
Plymouth
PL4 0RW
Tel:
01752 268795

These guys look after my bus.

Cheers,
Rob.

Thanks Rob

Looks like I will be giving these guys a call to see it I can get in at short notice.

Diagnosis is not good. At best the inlet valve is stuck open, at worse the engine is in a bad state.

I have a balance pipe between the dual carbs and each time the engine backfires (pops) you can feel the pressure back up through the carbs and hit the balance pipe. The RAC guy suspects that if it is not a valve then pressure is blowing from one cylinder into the next. So bad news whatever.

Not bad for a £3000 engine that has covered only 2500 miles. Feeling pretty pi$$ed...still, I suppose I can have a few beers as I'm not going to be driving anywhere for a while.

Look like I could be trailered home for the second time in 3 years.

Thanks again

Andy

 

[Baldrick]

Just to finish off the story the bus is back on the road and the damage wasn't as serious as first thought. I had one broken push rod and one bent one.

Strangely enough the same problem I had two yeas ago when I had to get trailed home from the very same place in Devon.

James Wooton (Veedubs in Welling) worked his magic for me and everything running well.

It seems that my rocker geometry was wrong and had been that way since the engine was built. Bit of a bummer because of all the inconvenience, but hopefully all is now sorted.

Thanks for the earlier comments.

 

[Trikky2]

Wow. To bend and break pushrods the geometry would have to be seriously out. [puzzled smiley]

 

[BJ1]

Wow. To bend and break pushrods the geometry would have to be seriously out. [puzzled smiley]

Indeed! I've seen a couple of examples of this over the past few years, some caused by engine 'builders' using those Mex heads with the long reach plugs (so-called "unleaded heads"). They are thicker than normal and require longer pushrods to restore the geometry.