Technical Very bad running after filling up with Bp super

[Robster160]

Hi all

just filled up with bp super unleaded and the car is now running very badly. Bad hesitation and dies as soon as I take my foot off the accelerator.
I have been told that really I need a new carb as the secondary throttle shaft is worn. Which is the reason I had been having trouble before with idle. But this is very sudden and bad.

thanks for any help

Rob

 

[Pugglt Auld Jock]

I really can't imagine, if it was running well before you filled up, that a change, say from supermarket "cheapie" fuel, to something like BP super, would give any change in the way it drives. Assuming you've not done something unexpected like putting some diesel in? - which is most unlikely I'd guess? or that the fuel you've taken on is in some way contaminated, it's likely you've some other problem which has just manifested itself, inconveniently, at the same time. If it's related to the new fuel I'd expect you to get a couple of miles down the road with her driving as she did before your fill up, while she sucked the existing fuel up the fuel line. only then would she quite suddenly, change as the new fuel got through to the engine.

PS I run my elderly horticultural machinery on "super" grade fuel because it's 5% ethanol so doesn't have much effect on the fuel lines and rubber diaphragms in the carbs. If I've got fuel left over at the end of the season, rather than letting it "go off" over the winter (Ethanol fuels don't like being stored) I just tip it in our Panda and, although the fuel may be a couple of months old by then, I've never noticed the slightest difference. Should have said my nearest station that sells 5% is a BP.

 

[Robster160]

Thanks for the reply.

It was probably about a mile or so after I filled up that the problem started. First just a minor hesitation, then it ran ok but then got progressively worse until it now will start but I have to use a lot of throttle to keep it running. I did wonder whether it had something to do with fuel pressure? When the tank was filled.

 

[varesecrazy]

Thanks for the reply.

It was probably about a mile or so after I filled up that the problem started. First just a minor hesitation, then it ran ok but then got progressively worse until it now will start but I have to use a lot of throttle to keep it running. I did wonder whether it had something to do with fuel pressure? When the tank was filled.

What do you normally run it on ?

RON rating change on a 'fixed' old school motor isnt like modern kit where everything makes adjustments out of sight



No guarantee that fuel isnt contaminated though..

Worth speaking to the garage after a day
... see if problems have come to light

 

[Robster160]

Thanks for your reply.

I usually run super of some sort. Usually Shell, but I thought I would try Bp because I think I read somewhere that it was a higher octane.

 

[varesecrazy]

More likely to be an issue with what you were sold..

Ask them if they have been misfuelled

Tankers can fill the wrong tank..it does happen !!


For you..

Every 5 to 10 litres you use... fill up with what you normally run


It should improve after a couple of fills

 

[Pugglt Auld Jock]

More likely to be an issue with what you were sold..

Ask them if they have been misfuelled

Tankers can fill the wrong tank..it does happen !!


For you..

Every 5 to 10 litres you use... fill up with what you normally run


It should improve after a couple of fills

Does sound like it doesn't it? The upside is that this is an old car so very unlikely to cause any serious issues with the fuel system. Put the wrong fuel in a modern vehicle and it'll usually end in tears!

 

[Robster160]

I have been told that it is probably water in the petrol. I am going to put some Wurst petrol additive in and see if that will disperse the water. At the moment it's too hard to drive. So I hope this works. I will let you know

 

[Pugglt Auld Jock]

I have been told that it is probably water in the petrol. I am going to put some Wurst petrol additive in and see if that will disperse the water. At the moment it's too hard to drive. So I hope this works. I will let you know

The obvious question is "who told you it's water?" If it's the filing station then you're going to be one of many with this problem and they jolly well should cover the cost of draining and flushing your tank. If some other source then did they in some way sample the tank contents or is this a guess?

 

[Robster160]

It was the garage that serviced and mot'd my car. When I described the symptoms they said it sounded like water in the fuel. I have spoken to the manager at the Bp garage, but he said they hadn't had any complaints. I've also emailed Bp

 

[Robster160]

Wurth petrol treatment didn’t help. Got the car running but it was still running badly wouldn’t idle. I took the idle jets out and cleaned them and it did seem better, but was very inconsistent. But I thought I would give it a run and see if the water would work its way through. Got less than 50 meters and it started to run badly with hesitation and a slight misfire. Got it back home and tried again with the idle jets, also looked at the spark plugs. they were very black and sooty, but I thought that might be because it had just been sitting running slowly for some time. Changed the plugs and got it running again. After a little while it suddenly started running smoothly. I assumed the water (if it is water) had worked it’s way through. Took it for another run, and initially it seemed ok. But just as suddenly it started running very badly again, worse than ever. It started misfiring and then bad backfire. just managed to limp it back home.

 

[Robster160]

Just as a follow up to my messages. I had a breakdown recovery guy look at it and straight away he said it was water in the fuel. said he never goes to Bp because of that problem. He took it to DTR sports and they drained the fuel, put new fuel in. It's now running perfectly.

 

[Pugglt Auld Jock]

Pleased for you to hear you got to the bottom of the problem. Water in fuel in a situation like this - where it's pretty obvious it's from a fill up at a petrol station - pretty much has to be down to storage tank maintenance. I never had much to do with the fuel side of any of the garages I worked in - some didn't sell fuel anyway - but I do know that there was a regular tank inspection by the fuel company (JET) at the DAF garage I worked for. The van would be seen from time to time at the pump island and I think he checked calibration too (quantity dispensed compared to pump readout) I know condensation and residue in the bottom of storage tanks can be something of an issue. I was advised to always fill up at a high volume sales outlet where these problems are supposed to be less likely.