Thankyou Mr Donk 

OK, so I understand that with emissions in mind that any gasses from worn rings etc. are oily so they want them to go into the combustion chambers and get burned.


And I can see that the inlet manifold is a source of "suck" to pull the gasses out of the rocker box and into the chambers, but.... what does it do to the mixture that the carburettor has just carefully made perfect?


Surely allowing unmetered, poorly mixed, probably not all vaporised, air and oil direct into the inlet manifold must do bad things to the vaporised fuel mix and therefore engine performance???


Surely it would be less damaging if it went into the air intake of the carburettor?


Why do we need "positive crankcase ventilation? surely "passive" ventilation would do? (it used to on all of my old UK cars...).


So surely it would be OK to just disconnect the line from the front of the rocker box to the manifold, block the hole into the manifold, block the outlet from the front of the rocker box, put a PCV valve on the rear hole in the rocker box and allow it to just vent any overpressure into the air filter? (and tidy up the rats nest of pipes around the engine and carb...)

Finally saved up the pennies and bought a Webber kit (32/36 DGEV WK551) from Quadratec and fitted it.
(First time I have ever fitted a carburettor - instructions were good, it was easy....).
Fitted an electric petrol pump at the same time (rather than fitting a regulator to drop the pressure from the nice new mechanical pump I fitted not long ago.....).


Started first time and runs smoothly. (Holy **** !!!)


Unfortunately it still "surged" under sustained load / up long hills etc..


Decided to experiment. (It was either that or commit suicide as a better death than telling the wife I had blown £500 for no benefit....)


Reading told me that "normal" Webber installations do not expect the "fuel filter with two outlets, one to return petrol to the tank if the carb doesn't want it" setup that the CJ7 has. They expect the Webber float seals to stop the flow from the (lower pressure...) electric pump without difficulty. So I put in a "normal" in-line fuel filter and just connected it to the carb.


This was useful as I was wondering what to do with the Webber "float overflow" output, and this allowed me to connect it to the fuel tank return pipe rather than having any overflow running out down the side of the engine.


Voila! the "surging" problem went away instantly!


Any ideas what was going on? Any problems with what I have done?

Cheapfest is back on again this year, it's at the usual venue of Coney green (DY13OTE)
It's a full weekend event as usual. With camping on site from Friday evening. £75 for the weekend for event attendees. Or £10 for those camping that don't participate
PayPal friends and family to Birtydastardsjeepclub@gmail.com

Copied from the FB post.

Hooray!, Do we need to book/pay in advance again???  if so where does payment need to go and how much?

A bit of a long shot, but I need an ECU for my 03 4ltr WJ. Apparently, they are year specific. Part no. is 56044634AE.
Can't even find one at Rock Auto. Can anyone help?

We’ve taken on the summer walters event from j33p.
26/17th July. £95 for the weekend or £50 for a single day.

10/11 September for cheapfest this year. Still at coney.

Breakout is the 6/7th of may next year. Plenty of camping available. £35 per day.

It won’t be the seat, I recon you’ve turned an interior light in by mistake while removing the seats. My kids do it all the time in my ZJ.