Got something to say or just want fewer pesky ads? Join us... 😊

Register Log in

Car Mechanics question



WATFORD zero

WATFORD zero

Well-known member
NSC Patron
Jul 10, 2003
25,809
I've got an old classic car that doesn't get used that often. I have just found out that unleaded fuel starts to 'go off' after a month in the fuel tank. As a result of this, it can thicken, causing misfiring and blocking injectors etc. It's something I've experienced from time to time and what I wanted to know is whether anyone is aware of any additives which would prolong the life or am I really going to have to drain the tank when it's not being used (generally over winter ?)

Also should i run the tank very low ? I've been keeping a fair amount in the tank thinking that I wouldn't be picking crap up form the dregs

Yours,

Confused of Brighton
 




Icy Gull

Icy Gull

Back on the rollercoaster
Jul 5, 2003
72,015
WATFORD zero said:
I've got an old classic car that doesn't get used that often. I have just found out that unleaded fuel starts to 'go off' after a month in the fuel tank. As a result of this, it can thicken, causing misfiring and blocking injectors etc. It's something I've experienced from time to time and what I wanted to know is whether anyone is aware of any additives which would prolong the life or am I really going to have to drain the tank when it's not being used (generally over winter ?)

Also should i run the tank very low ? I've been keeping a fair amount in the tank thinking that I wouldn't be picking crap up form the dregs

Yours,

Confused of Brighton
Click to expand...

When I bought a new lawn mower a few years ago I was advised to use this stuff in the fuel over the winter. I imagine it works just as well in car fuel tanks? The other downside of emptying a fuel tank on an old car is that the tank is probably metal and is more likely to rust if empty?

https://www.briggsandstratton.com/eu/en_gb/support/videos/browse/briggs-and-stratton-fuel-fit.html
 


Spiros

Spiros

Well-known member
Jul 9, 2003
2,361
Too far from the sun
WATFORD zero said:
I've got an old classic car that doesn't get used that often. I have just found out that unleaded fuel starts to 'go off' after a month in the fuel tank. As a result of this, it can thicken, causing misfiring and blocking injectors etc. It's something I've experienced from time to time and what I wanted to know is whether anyone is aware of any additives which would prolong the life or am I really going to have to drain the tank when it's not being used (generally over winter ?)

Also should i run the tank very low ? I've been keeping a fair amount in the tank thinking that I wouldn't be picking crap up form the dregs

Yours,

Confused of Brighton
Click to expand...

I too have a somewhat battered classic that's never been converted to run on unleaded but somehow does. I was advised by the guy who does the MOT to always fill it with premium unleaded instead of the basic stuff if I'm going to leave it in the garage for lengths of time. After a long run of crap weather recently started her up reasonably promptly some 4 months after the last drive, took a while to start but otherwise ok
 


D

Deleted member 2719

Guest
Modern fuels do go off quicker, they also have more tendency to hold water, so I would keep tank full so less chances of condensation and add a quality additive to stabilise the fuel from going off (usually about 3 months) something like Millers.
http://www.millersoils.co.uk/treatments/classic

Or you could just drive it all the time!
 






D

Deleted member 2719

Guest
WATFORD zero said:
I've got an old classic car that doesn't get used that often. I have just found out that unleaded fuel starts to 'go off' after a month in the fuel tank. As a result of this, it can thicken, causing misfiring and blocking injectors etc. It's something I've experienced from time to time and what I wanted to know is whether anyone is aware of any additives which would prolong the life or am I really going to have to drain the tank when it's not being used (generally over winter ?)

Also should i run the tank very low ? I've been keeping a fair amount in the tank thinking that I wouldn't be picking crap up form the dregs

Yours,

Confused of Brighton
Click to expand...

What is your Classic car?
 


beorhthelm

beorhthelm

A. Virgo, Football Genius
Jul 21, 2003
35,303
i hadnt heard of this before, and my Dad has had VW that get left unstarted for months even years and splutter into life with the fuel left from before. i do recall there can be roughness and problems put down to condensation in the cylinders and carbs "gumming up" from evaporated petrol leaving behind a residue.

looking it up seems inconclusive if going off is a thing, and if it is would take more than a month. evaporation may leave the fuel lightr on some more volitile ethers seems to be behind it, so the best additive would be a fresh topup of fuel.
 


WATFORD zero

WATFORD zero

Well-known member
NSC Patron
Jul 10, 2003
25,809
Mouldy Boots said:
What is your Classic car?
Click to expand...

001.jpg
 






RandyWanger

RandyWanger

Je suis rôti de boeuf
Mar 14, 2013
6,032
Done a Frexit, now in London
WATFORD zero said:
View attachment 89781
Click to expand...

That's about 40 years newer than my classic LOL Nice car though.

From what I remember, new fuels have more additives in them which cause the going off. Cheap fuels with higher ethanol content are the worst as it corrodes fuel lines. High quality fuel tends to last longer. I've had a tank of Optimax in mine that's been off the road for 3 years now and still starts (eventually) on the odd occasion I've tried.
 


beorhthelm

beorhthelm

A. Virgo, Football Genius
Jul 21, 2003
35,303
pfft, "old classic" think i have pants older :D

nice though and should have a monthly "italian tune-up" to make this petrol thing a non-issue.
 






BigBod

BigBod

Well-known member
Dec 12, 2014
354
Once there is salt on the road my motorbikes stay in the garage till Spring so usually 3/4 months. I always fill the tank with normal unleaded to avoid condensation, put them on a battery tender, cover em up and leave em till Spring. Come Spring they get a service and off I go again.. Had one of the bikes 16 years now and still runs sweet as a nut and never had a problem with carbs gumming up or any other fuel related issues. If it ain't broke don't fix it or, if it ain't broke fix it till it is...lol. You can tinker too much some times.
 


WATFORD zero

WATFORD zero

Well-known member
NSC Patron
Jul 10, 2003
25,809
Mouldy Boots said:
Hmmm left hand drive, are you sure it's not one of these.

View attachment 89782
Click to expand...

Sorry, didn't have any pics of mine handy, this is mine

3small.jpg

grubbyhands said:
Blimey, is that really a classic car, it seems very recent. Fuel stabiliser is the answer, as posted, and keep the tank almost full up. Don't be tempted to just start it up and run it briefly for a couple of minutes, you'll rot the very expensive exhausts.
Click to expand...

Well it's 18 years old, so not exactly new and I'll try the stabiliser :thumbsup:
 


D

Deleted member 2719

Guest
grubbyhands said:
Blimey, is that really a classic car, it seems very recent. Fuel stabiliser is the answer, as posted, and keep the tank almost full up. Don't be tempted to just start it up and run it briefly for a couple of minutes, you'll rot the very expensive exhausts.
Click to expand...

Residue from the stabiliser or just water that's produced when cold that rots the exhausts???
 


You must log in or register to reply here.

Share this page

Albion and Premier League latest from Sky Sports


Top
Link Here