CU Back firing help

Post by **Uberpussy** » 22 Jun 2008, 13:40

Ok I've just installed a CU Aircooled dual carb in replacement of my water cooled and it's running bad, back firing all over the place and cutting out.

I've converted it to electric fuel pump but other than that it's a standard CU with dual carbs etc. I've gapped the points and set a default timing position as I would with my 1.6 T2's but its just not right.

It sound to me like only one side is firing but thats purely speculation on my part.

Anyone got any ideas on possible causes or some fault finding help?

Post by **Mocki** » 22 Jun 2008, 13:46

why have you put olde worlde ignition on it?
CU's are electronic ignition, there shouldnt be any points
sounds to me like its timing way out from here.........

Post by **Uberpussy** » 22 Jun 2008, 13:54

Mocki wrote:why have you put olde worlde ignition on it?
CU's are electronic ignition, there shouldnt be any points
sounds to me like its timing way out from here.........

Urm are you sure. I thought all the Aircooled where points?!? Certiantly thats what the block came with. Even the water cooled I replaced was points.

Anyway I'll go back to the timing and try again cheers.

Post by **cumbriankeith** » 22 Jun 2008, 14:33

I too thought all CUs were electronic ignition but were some fitted with points apparently.
Back firing can be caused by air leaks into the many complex bits of pipework these engines have to do with carbs, idling carb, as well as takeoffs for vac and servo. What carburetion does it have?

Post by **Mocki** » 22 Jun 2008, 14:35

if it is points, and the old wbx was points, the hard of thinking have been fiddling! The 009 dissy isnt correct for these engines, but they will run on them , sort of

Post by **Uberpussy** » 22 Jun 2008, 14:59

I stand confused.

The old WBX was electronic sorry but the CU is not. I'm gussing a straight swap of the electronic WBX to the CU is not going to happen?

----

Well to answer my own question it is a straight swap and the CU engine is running great now!!!

I get the feeling that the engine I brought isn't in the orignal state it was when it was dropped.

Cheers for all the great advice people I could have spent days tinkering with points etc, when a five minute swap out was all that was needed!

Post by **Uberpussy** » 22 Jun 2008, 17:34

Actually it running well right until you try to drive it and there is little power there, even advanced a little it still runs with zero power. Yet it idles fine.

Any more gems of wisdom to fix this one?

Post by **Mocki** » 22 Jun 2008, 17:44

see now im wondering , you swapped the WBX dissy onto the CU ..........

the wbx dissy isnt the same as the CU one i dont think, although the electronic ignition is, just the dissy isnt......someone with a better memory will be along soon......

is it getting enough fuel, and are the carbs balanced..... its awkward to tell from here!

Post by **Ye Olde Syncrospares** » 22 Jun 2008, 18:28

2 litre bay=CJ code -points ignition,2 litre wedge =CU leccy ignition,never seen one with points yet,if its got a 009 in it bin it,if youve put a water boxer dizzy in it bin it,yes itll run but it wont be happy,have you checked your engine code and by this i mean actually checked yourself???,misfires are caused by blowing exhausts and air leaks and running lean,get it too a rolling road at some point to set it up,cj.

Post by **Uberpussy** » 22 Jun 2008, 18:33

Mocki wrote:see now im wondering , you swapped the WBX dissy onto the CU ..........

the wbx dissy isnt the same as the CU one i dont think, although the electronic ignition is, just the dissy isnt......someone with a better memory will be along soon......

awaits... :lol

Mocki wrote: is it getting enough fuel, and are the carbs balanced..... its awkward to tell from here!

Its just as awkward when your me at this end

The fuel flow *seems* fine but it is a new electronic pump so I'm not 100% convinced on that front how does one tell if enough is getting through?

I have no idea how to balance the carbs as only ever messed with single carb engines before, any pointers?

Post by **Mocki** » 22 Jun 2008, 18:56

while we are at it, where is "here"?
put your location in your profile, someone maybe just up the road, who can help........ like CJ says, go look at your engine number, is it really a CU?

Post by **Uberpussy** » 22 Jun 2008, 20:16

Mocki wrote:while we are at it, where is "here"?
put your location in your profile, someone maybe just up the road, who can help........ like CJ says, go look at your engine number, is it really a CU?

There is no engine number just a spiral symbol and the letters CU. I've cleaned the area where it's supposed to be but I really can't see anything.....is it likely to be hard to see?

....beginning to wounder what I've got my hands on...

Post by **Mocki** » 22 Jun 2008, 20:21

its a rebuilt CU then....... as you were!

Post by **Uberpussy** » 22 Jun 2008, 20:48

Mocki wrote:its a rebuilt CU then....... as you were!

Where was I again?

So given it came with a 009 and Im assuming it was running on that what is my best option to put in there now if the WBX isn't good?

Can someone point me in the direction of a good place to pickup the required distrib?

Post by **Mocki** » 22 Jun 2008, 20:56

where to get a CU dissy......... ummm....... erm........ post a wanted add in the wanted forum....... some of the breakers on here might have one, Billy739, T25 Spares...........arghhhhh , ummm........ try the JK kamperchat forum, and VZI too......