Idle and Rough running Driving me mad...

Thought I had fixed my issues earlier this week, not the case, drove to work and back today, issues again stalling, not running quite right, seems worse at low speeds. It doesn't seem to stall once the engine is at full operating temperature but still runs rough, cruises at 60 mph no probs.

I am planning a bit more investigation tomorrow but am just wondering if anyone has any pointers. I am going to follow Ratwell regarding tuning up and also the other very good write up available from Samba (the one with the handsketch pictures!). I am thinking do I look at a new distributer and or fuel pump?? Just driving me mad now...

Its a 2.0 l type 4, stock solex PDSIT 34's, also the van seems to be using more fuel that normal, the dipstick was lukewarm after the 25 mile run today so I assume that the engine aint running hot, any ideas chaps??

 

Nope, don't have an air supply, can I get these out without major dismantling of the carbs??

 

Maybe running rich as symptoms not so bad at cruising speed and fuel consumption worse. Have you tried a "plug chop" which means taking the bus for a run and removing a spark plug afterwards then checking the colour which should be "brown to greyish tan colour" according to the bible by Haynes. If it's sooty / black it's a rich mixture which would give you a starting point. Have a look in any old Haynes manual and it's probably on the inside of the back cover as the only colour page under "Common spark plug conditions". If you haven't got access to one let me know and I'll scan a copy
Hope this helps in some way and you get it sorted
Mr B

 

Keep it simples mate , obviously I do not know the history of your own bus but that buying/replacing parts in an attempt to find/cure a prob is the road to financial and spiritual ruin, did it run ok previously?have you altered/changed anything ?good tip I had many years ago from a wise old sage was " service it ,set it up as book says" >does it run ? if yes ,its a sub system prob ,perhaps adjustment ? as other fella says ,blocked ,semi blocked jets can be a bugger (I know) my 2 pence worth ? how fit is the coil and associated parts ,?not something you can "see" but perhaps worth checking out

 

Thanks for that, I was going to do that tomorrow, have a look at the plugs, just lost it a bit today as this has been going on a while. After a beer or two tonight I hopefully will be ready to apply some logic tomorrow...

 

Cheers Steve, you are right, keep it easy and logical. History is, dropped engine over the winter for some body work. Engine went back in at Easter with new clutch. Have since replaced coil (no reason other than felt it was time), new plugs and points, fiddled with the carbs and also had the MOT man set the timing and tweek the carbs but hasn't worked.

Do you know, can I get the jets out without dismantling the carbs??

 

Use a can of butane lighter fuel. Someone on here, Para i think, gave me this tip. Works a treat. Pilot jet is on RHS on a 34pict standard carb. easy to get to.

I had similar issues. Twas my auto fuel cut off solonoid.

 

I'd look at what you changed. Try the old coil? Points gap?
I don't believe the MOT man will have the skills to adjust these complicated carbs...

 

Cheers Zed, will do,

 

As Zed said re carb adjustment.

 

Do you have hydraulic lifters? If they need a service these symptoms sound right. Incorrect valve opening resulting in higher fuel use and rough running See the ratwell write up as asallsorts can effect them. Oil that has a too high or low viscosity when cold or hot etc etc etc

 

yes I do have the hydraulic ones, never fiddled with them...I am using the same oil as I always have in my 3 years owning the van, its clean as of 300 miles ago...

 

User jt1 has just experienced rough running problems finally pinned down to lifters after weeks

 

Need to read the ratwell article again but how major is the work required to service the lifters, just we have camping trips booked and I don't want to find that the van is out of use, if that's needed would prefer to leave it until the autumn,,,

 

Ratwell says that leaving the van standing for a period of time can cause the lifters to "drain" therefore need rebuilding under oil. To take them out its rocker covers off rockers and pushrods out, pushrods tubes out, pull lifters out with magnet on a stick. Check and rebuild. I have has mine out of the block for 12 weeks but stored under oil after rebuilding.
I would exhaust all other option before going down this route

 

Check all carburation system pipes and tubes. Look for cracks etc and if they are actually present. The ratwell article mentioned is very good. Hydraulics if they are sticking will rattle a bit. A mechanics stethoscope makes it easy to pin point these. Do a compression test before taking stuff apart. Chokes opening correctly and roughly the same time. Are the points ok, check them for exssive pitting and any carbon deposits. Not such a good indicator with the modern materials used these days.