340 1.4 rough ans slow idling
 

Hi there, I'd be grateful for some advice.

My 340GL manual has run well for years.

A few days ago I filled up at the local Asda Petrol Station, after a short distance the car was tending to stall and tickover slower than usual and rough, something like 200 RPM.

The next morning I started the car and again had the same problem I disconnected the fuel feed to the carb and pumped out about 2 litres of fuel. Reconnected the feed and car ran OK. The next day I did a round trip of about 10 Miles and the car was fine. However, today the car is playing up with the same erratic and slow idle.

I did contact Asda about the possibility of contaminated fuel, they responded on the day that I filled up, several hundred cars filled from the same tank and no reported problems other than mine.

I have checked distributor, rotor arm, air filter and for air leaks around carb. The ignition leads are fairly new.

Of course, MOT is due soon, so I need to resolve this. Many thanks in advance.

Would i be right in saying it's also harder to start cold and tempremental until it's warmed up and even then not as it should be?

If so, it sounds as if you have a build-up of condensation in the tank, worth trying as a "first port of call". Wait until the fuel level is down to ~1/4 tank (about 3 gallons left) then add 2L of meths to the tank :

https://www.toolstation.com/methylated-spirit/p99550

Cheapest way of buying it at that volume as far as i know. This will emulsify with the water and allow it to be burned off normally. If it doesn't work, it's cheap enough to know you've tried a quick, cheap and easy fix that has got rid of the condensation. Note that the best ratio is 1:10 so more than 3-4 gallons of petrol will dilute it too much to have any real effect.

Hi, thanks for the useful reply.
I going near Toolstation today, I'll get some meths. Yes, more temperamental when cold, but still bad tickover when hot. Of course, Ive got over half a tank of petrol.

Apologies for the typo in the title. Must concentrate!

Testing the car yesterday, Ive got good brakes on the 340, was going to go through the second set of traffic lights, decided to stop. Range Rover to the left of me decided to go through, he got flashed.

My £6 dashcam filmed this.

https://youtu.be/SQHPWMLzR_w

Just got back from Toolsation to get methylated spirits, car still playing up, bit like kangaroo petrol. Relatively new thing, engine ran on a bit after turning ignition off. Does not usually do that.

You've still got over half a tank of petrol so you haven't put the meths in yet so if it is condensation it will be.

No, not put meths in yet. Will get the tank a bit emptier first. Will be doing a few miles tomorrow, then perhaps over the weekend will pump some more out of the tank. I have a little electric pump for this, about thee years ago I filled with diesel by mistake!

Good idea pumping it out! If you can, put it in a clear container to settle, you'll see the condensation/water at the bottom if you happen to pump any out from the bottom of the tank.

Three years ago when I pumped out the diesel. I just disconnected the feed pipe to the carb, and connected the electric fuel pump to that. I need to find some empty cans though!

Just noticed another error of mine, I'm registered here under two names, this one and 340man.

What about a 25L tub from somewhere? Many places that use clear plastic 25L tubs are happy to let one go free or for tuppence ha'penny and a brass farthing.

Pumping from the carb feed pipe would also mean you're pumping from the bottom of the tank so likely to get a lot of the condensation - could be why when you did similar and got the engine started you pulled through some petrol instead of condensation.