Hi can anyone help I have a 79 late bay with 2.0 petrol engine the same as what's in the type25 it has twin soles carbs but failed mot on emissions just over what can I do to lower them ? Also I found a fuel cat leaflet in the glove box I think previous owner has fitted one already looking through the old mot failures its had issues already it doesn't smoke and starts and runs perfect.
Sounds like you need your carb set up mate, mine runs very lean but it gets through the emissions every year so I haven't done it. Any decent garage should only take an hour to sort unless you have a gas machine and can do it yourself
you might have to ask the tester ,my old tester used to do it....you need a machine you cannot just turn the tickover down...
Pre-March 75 vehicles are subject to a visual test for emissions only. This means - the tester revs the engine, then walks around to the back of the vehicle and looks at the exhaust. If there is "too much" smoke coming out of the exhaust, he fails it.
I had one test where the MOT tester who was having his tea break as I arrived. He watched me as I drove in and parked in the "MOT vehicles" parking spaces ready for the test. When it came to the emissions test, he just kept hitting the return key on the computer without looking at the van. I asked him if he needed to look at the exhaust. "Looked alright to me when you arrived earlier" was his reply.
So do I need expert to set the carbs leaner on a machine I'm reluctant to adjust the carbs my self is this the only way.
The very FIRST thing to do , is check your breather elbows, located on the cylinder heads and one other one at the back, These perish, and end up being taped up, but will leak air, causing poor running, which people compensate for by upping the fuelling. Mine was 'well rich' but replaced the elbows, (IIRC about £5 each?) retuned the carbs 'a la well known american vw website' (can't remember the name, its a workshop blog thing) and reset the timing, and its good with a CO reading of 3.21% (4.5% max) and HC of 122ppm (max 1200ppm) And pamplemousse is a std 2000 t4 lump, with a best of 33.4mpg. PS check out the SOLEX thread, that has the article I was refering too, that I tuned mine with.
If you DO try it yourself, remember that they are not ACTUALLY twin carbs at all, they are effectively a single carb with a secondary remote outlet, ie idle mixture etc is on the top of the LH carb, but this affects both carbs, and you balance the pair (by ear, its really quite easy) but as said make sure youre timing is spot on, and the elbows have no air leaks. Oh and the mixture screws do take a bit of finding, they are low down, behind a bit of a lump and face forwards (towards the front) so very difficult to find first time.
Thanks guys I took to my wife's hq fire station at there workshops sorted it £55 runs mint for another year anyway
