Erratic Revs, Spluttering and cut out. Mk2 1.6 1984 Golf EZ

i still have the swirl pot on mine
not had an issue with it other than when the lines degraded, had little bit of muck float about in the fuel then
so having done the lines and clean everything out, mine is now back to behaving itself (touch wood)
as for your idle issue have you checked all your VAC lines, any holes in them will cause that sort of thing to happen

 

I've checked the all Vac lines and none are damaged or come disconnected in anyway, they were replaced when I did the rebuilding of the carb. I know it's something to do with that as everything else is in good order all that was changed on the carb was the gasket and the jets before hand it was running okish compared to how it is now. To be honest I don't have much history on the carb as to wether it was a brand new one fitted or a second hand one when I bought the car. I will be changing it though but until then I want to at least get it running fine without the fear of it breaking down, hesitating or refusing to start after driving

 

jonny
what does this restrictor look like?
cheers
john

 

Hi Jonny.

I've tried to restrict the return pipe (used an old carb jet similar to the one that used to be on the t-piece that Webers came with) but still getting the same problem as before. Even cleaned out the swirl pot (nothing but pure fuel) took it for a spin and it just wanted to die out so had to put the choke out to keep the revs up to prevent that from happening. So I'm sure it must be the carb that has a problem but as to what I really can't say.

So far all the fuel lines in the car are clean and new in the engine bay) no vacuum leaks, the mechanical pump is new from heritage (second one and after testing the other no fault was found with that) carb has been rebuilt and new jets and filters fitted.

I'm at a lose to be honest.

 

Just out of curiosity would the heating element on the inlet manifold cause a problem if it's not working properly? I only ask as it's something that I may have overlooked.

 

Hi Jonny,

The rubber flange is in good condition with no splits & I done the simple checks like block airflow (cuts out as expected) and sprayed carb cleaner to see if there was any denoting within the idle speed on the manifold and baseplate and nothing was out the ordinary. I cleaned the spark plugs and also changed the air correctors for different ones (not the ones for a 1600) car idles fine but now backfiring when I rev to 2500 3000 rpms. Drive it around and still get the same heasitation as before.

I'm still planning on changing to twin 40s anyway but would like to try and sort out this problem in the meantime in case it's something else and not the carb. On a different note is there any problems that I'm likely to encounter when I change to twin carbs in relation to fitting them. I've hear the master cylinder (brake booster) can cause fouling.

Cheers.

 

I'm planning on fitting a facet solid state fuel pump to run the 40s and use a malpassie filter and regulator the latter already being fitted. The pump that is currently on is new as I also thought the same thing as did the guy from the AA when it broke down last. I've taken the fuel line off and turned it over to make sure there was a good flow which there is (ran it into a bucket to make sure.) I'll try get the facet pump fitted and see if that makes a difference. Where would be the best place to mount it as I've heard under the car near the tank but as mine is lowered I don't want it being torn off by a speed bump. Also trying to figure out how to wire it so it only works when the ignition is on (engine running)

Cheers.

 

Thanks for the tip. I was originally going to wire it up to an oil pressure switch but the way you have suggested sounds a lot easier and less faffing about. I may have to pick your brain again Jonny if I get stuck but I'll check the Haynes manual also.

Thanks

Edit

Does anyone know what jetting I would need for twin 40s in a 1600? Or where I can find that information?

Ta

 

re-reading jonny's posts i think he means the none return valve in the vac line as it comes off the side of the inlet manifold on its way the brake servo.
the valve has two pins on it, one for the carb and one for the reservoir, the one for the reservoir is blocked off and only the one for the carb remains in place.
the return line on the fuel is still needed do not block that off.

 

I'll try get a picture of my set up, up tonight just so everyone can see, but to describe mine I have the brake servo hose coming off the manifold then a valve with two nipples one to the carb and another to the dizzy then continues to the brake cylinder. The return has been restricted with a spare jet but that has made no difference, all vacuum lines are in good order along with the rubber flange the carb sits on, no vac leaks at all (it's tighter then a nuns bum) the other theory I have though of is carb icing which never really occurred to me until I spoke to someone at VWHERITAGE who suggested they symptoms sound similar but even he suggested it maybe something else. After a bit more research some of the symptoms I have had do appear similar to carb icing but want to be 100%.

Still changing to 40s tho as I managed to get a good price for a brand new set built to spec for a grand total of 672

If anyone can think of anything that may help I appreciate it. Thanks guys.

 

Ahh this could explain the reason for the intermittent problems then. Unfortunately the conversion was done prior to me buying the car and the original air box was not fitted the previous owner had a foam one placed on which he cut so it would fit, I then got a K & N filter to replace it. I did get the air box off him but I think bits are missing for it (ain't really looked at it to be honest) so I should remove that vacuum line altogether and block both the outlet on the carb and the nipple on the other end?

 

I will run some tests over the weekend (permitting weather) I have added a photo of my current set up so you can see and also if I've missed something.


https://www.flickr.com/photos/147939594@N08/shares/0471ea

sorry about the link for some reason the upload feature on here doesn't seem to be working. the link is off my current engine setup. The foam filter is what the previous owner had done when i bought the car