Fuel Starvation with vw carb... Solved

[freeflyd]

After Bennie did the vw carb conversion for me I could not be happier. The engine sounded better, felt better and the fuel consumption was dramatically better.

I have now done about 2 500km after the conversion and have a problem with fuel starvation. It only occurs when the engine is at running temperature and only below 2 500 rpm. The other times I have experience the same symptoms were when my dizzy got wet and when the fuel pump wore out. It is most apparent when I'm pulling away and changing up through the gears. When I'm at cruising speed there seems to be no problem at all. My fuel consumption is slightly higher, but that's probably because I have to drive her harder to get going...

My first thought was that I might have a dirty fuel filter, so I replaced that. Then I thought that the carb mounting might not be sealed perfectly, so I re mounted the carb with new gasket and that didn't help either. My next guess was petrol pump, so I replaced that and still no joy. There are no leaks in the fuel line either and the idling is smooth.

It is almost like the carb needs both throats open to get enough petrol into in the engine.

I don't know a lot bout engines or carbs, so I don't even know where to look. Could it be a problem with the electronic dizzy?

Bennie: Perhaps you could send me a phone number for Oom Albert so he could have a look at the spark plugs....

Any other thoughts might be helpfull.

[BenHur]

Why don't you come and make a turn?

[Scooter]

When you installed the carb, did you guys use the "surge pot" that the golf 1's have? If not, install it !!

With my old golfie I was experiencing the same problem and after much searching and changing of things I decided to add the pot. It cleared the car of all fuel starvation problems.

Back in the day I had to aquire mine from a breaker, but I'm pretty sure Goldwagen will have.

(In case you dont know what Im talking about, it is a pot that normally sits on the front of the head and has a inlet & outlet for fuel as well as a return outlet. I reckon it would be worth a try)

[freeflyd]

Thanks Scooter.

We had a look last night at Bennie's place and it seems like the carb might be sucking air past the mounting plate. I'll get an original mounting plate today and install it tonight to see if that makes a difference...

I'll ask them about a surge pot, but have to admit that I have no idea what that is...

[Scooter]

Take a look here : viewtopic.php?f=1&t=4047&p=44404&hilit=surge+pot#p44404 to see what the surge pot looks like.

[BenHur]

I dont think it requires surge pot as it is not a case of the carb running dry on hogh RPM but rather something to do with teh engine running lean on low rpm.

We krapped with it again tonight but no joy. It feels as if the jet on the 1st barrel of the carb is suddenly too small as she has the feeling of running lean on the 1st barrel. She pings and if I slow down the timing to where she stops pinging the engine accelerates very ruff as if she does not get enough fuel in. If I advance the timing she pulls much better but then pings all the time.

Dawie will take her to Schalk 2morrow to check her out.

[MORNE]

Make sure it is a orig. VW. carb, I think its call a Nikki carb .You offen get inported carbs made in China and they do give a lot of simular problems

[Scooter]

Make sure it is a orig. VW. carb, I think its call a Nikki carb .You offen get inported carbs made in China and they do give a lot of simular problems

I fear you have confused the Hilux 4Y carb with the VW one Morne. The original VW carb is actually a "KEIHIN" or if you go even older than that you will get a "Solex".

Bennie / Freeflyd, I would install the "pot" (and not the green stuff ) anyway to be safe. They dont cost that much but will save you alot of trouble. On the golfie I suffered for months. After rebuilding the motor and removing my weber 34D due to it running so lean it burnt the valves , I installed the Keihin carb. For a while it was fine then this same thing started happening. It wasn't running dry either (that I could tell anyway) and after installing the pot, it went away and I never had another days trouble.

For some reason the golf carb prefers to have that extra bit of fuel waiting for it, especially on mechanical pumps.

[BenHur]

Turned out the problem had nothing to do with the Carb but rather a misfire due to carbon build up on one of the plug leads' connections where it goes over the plug so at a certain RPM (from about 1200 to about 3000RPM) she was not firing correctly. We did actually looked at the firing the other evening briefly but did not look too deeply since by removing the plug leads individually while she was idling the engine's RPM did drop with each individual wire that was removed. We also did not see any sparks around the leads in the dark either, bit in this case because the plugs are inside the head we did not see any sparking pass the side of the plug. Wel so leer mens né

[freeflyd]

Enough said... Thanks Bennie!