Fuel Problem...please advise.

[TeamBrian]

My engine is suffering from a flat/sickly spot when you start to lift the revs from idle, then it passes once you increase the revs. I'm finding it really annoying as you have to keeps the revs up all the time in town, which isn't really my style of driving. It's an AB engine and the valve clearances and timing have just been checked/adjusted and the fuel set according to the Bentley manual. It's a Bocar carb and is fairly new. Any advice would be greatly appreciated.

 

[StuF]

What sort of condition is your acclerator cable / linkage in? Might just be some slack in the cable?
Sorry I cant offer any more advice

Maybe renew your linkage with one of Buttys kits and see if that improves things - made my throttle much more responsive and easier to set the idle correctly as there was absolutely no play left in the cable from the pedal to the carb.

 

[TeamBrian]

Hi STuF, yes the cable's OK and the problem still occurs when you operate the throttle by hand. I bought myself a Butty's Bits linkage too...another job on the to do list! Cheers.

 

[Zcat7]

I would check timing and the accelerator pump. The pump could be poorly adjusted or maybe the diaphragm is split. Had the same thing myself recently (although with twin Kadrons) and it was the accelerator pumps.

 

[TeamBrian]

Thanks for that. I'm heading now and I'll report back later

 

[privatejobs]

try and get a genuine vw carb bocars are shit

 

[TeamBrian]

Agreed, PrivateJobs. I'm going to have check the timing again as I've just found out that I've set it incorrectly, and read up on adjusting the accelerator pump.

 

[NellyM]

My bus suffered with a really bad flat spot which seems to be what you are describing and I tried all sorts - new carb, timing, valve clearances etc and in the end it was down to carb icing. Run your engine until it gets hot and check the temperature of the heat riser tubes coming up from the exhaust to the inlet manifold. On my engine one side was stone cold whilst the other side I could barely touch which proved it was blocked. They tend to suffer with a build up of carbon.

New inlet manifold fitted and she runs like a dream!

 

[john the horse]

009?

 

[jonboylaw]

John, looking at his other thread then it is a 009. Good call.


The flat spot is possibly (likely) caused by lack of advance coming off idle as there is no Vac advance to help pull the advance forward on a 009. SVDA would cure it. Try and borrow one to see.


Sent from my GX64 SatCom phone using Tapatalk

 

[Tofufi]

As above - my money is on it having a 009 distributor.

 

[TeamBrian]

Correctomondo, it's a 009....possibly part of the problem!

 

[jonboylaw]

Possibly the whole problem. Borrow an svda and see if it cures the issue.


Sent from my GX64 SatCom phone using Tapatalk