WBX running problems

AMBROSIA · Post by **AMBROSIA** » Thu Apr 17, 2008 10:59 am

Having a frustrating time with my WBX beetle

The engine has an intermittent problem where it will be running fine and then suddenly starts stuttering when cruising.
If you ease off the power it is smooth and if you accelerate it picks up smooth. Whilst cruising at one speed it sounds like it's missing and then occasionally picks up speed and then is smooth again

I took it to a rolling road and of course it behaved itself. The tune up went with no hitches and the drive home was fine.
Took it out next day and after 30 mins of driving it started playing up again.
Today I drove to work and back. It was fine until just arriving and then started again. Coming back home it did it from a cold start all the way.

So far I have changed:

Fuel pump.
Hall sensor.
Distributor cap.
Various HT leads.

The carbs are reconditioned.
The main and idle jets were changed during the tuneup.
I have ordered a new coil and rotor arm but it does not sound like an ignition problem.

I just can't see a pattern that would cause this?
Any ideas people?

AMBROSIA · Post by **AMBROSIA** » Fri Apr 18, 2008 1:30 am

Looks like I have spotted the problem.
I am running the fuel pipe to the left carb and then across to the right carb.
When the problem starts the right carb filter is empty so it appears to be a fuel starvation issue.
I will run the carbs of a T piece to see if that helps.

Moog · Post by **Moog** » Fri Apr 18, 2008 4:43 am

Check your fuel tank breather - if it is blocked or blanked off then after a while you will get a vacuum in the tank, which will man the pump can't suck the fuel.

AMBROSIA · Post by **AMBROSIA** » Fri Apr 18, 2008 5:36 am

Check your fuel tank breather - if it is blocked or blanked off then after a while you will get a vacuum in the tank, which will man the pump can't suck the fuel.

Yep, will do.
It's strange as there must be fuel getting to the right carb but only when the vacuum level increases.
The problem was still there just after filling the tank up.
I think i'll clean out the fuel pipes as well.

AMBROSIA · Post by **AMBROSIA** » Sat Apr 19, 2008 11:05 am

Still having problems

Today I changed the fuel pump, put on bigger fuel hose and used a t-piece.
Once again it's missing and running rough but I can see fuel being delivered to the T-piece

Once you get going above 3k it runs ok and accelerates well but soon as you drop to idle it splutters and dies. I then check the engine and the fuel filter has fuel in it.
I guess i'll be replacing the remaining ignition parts next

AMBROSIA · Post by **AMBROSIA** » Sun Apr 20, 2008 5:15 am

Ok today I changed the coil, checked the HT leads and replaced the coil lead, checked and cleaned the ignition box and still no joy

It's bizzare, it won't idle from start which with dell 40's is not surprising but once warmed up it does.
Then you leave it tick over for 30 seconds and it just dies.
If you catch it in time and rev up it then settles an idles again.
I tried removing the filler cap in case of a vacuum but it still dies.
The only thing left unchanged now is the ignition module.
My question is what module is likely to work?
Currently it is fitted with a fairchild as it's matched to the 1.9 distributor.

Has anyone successfully fitted a later module perhaps from a golf?
Gotta get this sorted before next weekends show.

1303wasserbug · Post by **1303wasserbug** » Sun Apr 20, 2008 10:39 am

sounds to me like fuel mixture is off can you get it to a mot station and test co? also what timing are you setting at? that ign mod thingy is the same as a load of cars from bmw's golf's and some vauxhall's too.

AMBROSIA · Post by **AMBROSIA** » Sun Apr 20, 2008 2:25 pm

Just had the car rolling roaded and he did the timing and jetting etc.
Today I went to see a mate and everything was running perfect

Tonight I ordered a new ignition module so hopefully that will solve the problem.
Hope your motor is running well mr 1303r

Will you be going to any shows this year?

1303wasserbug · Post by **1303wasserbug** » Mon Apr 21, 2008 9:28 am

yeh i read you had it rolling road tuned. i just don't trust anybody

. thats why i now have an innovate data logging system in my car. nope my engine is not running. i'm putting it together now, got fed up everything was going wrong so brought myself an old datsun to drive. now i need to put the bug back together before i can turbo the datto

AMBROSIA · Post by **AMBROSIA** » Tue Apr 22, 2008 12:50 pm

Fitted a new igntion control box today and I must say the engine feels much livelier

It started up with a few burbles from the carbs but then sat idling perfectly for about 10 minutes.
Fingers crossed that's solved the problem.