F***ing Vapour Lock! - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Martin · 11-07-2003, 09:10

AHHHH, this is giving me the shits!
I pull the car out of the garage to do some work on it yesterday, a few hours later I go to restart the car to put it back in the garage, and it just cranks, cranks, cranks, for around 10-15secs until finally it starts, coughing and spluttering for a good minute or two. With a very rich fuel smell and black cloud out the exhaust. Max temp was 24C.

Give it a few weeks and im not going to be able to drive it as its just too much of a pain to restart it on hot days, first noticed this during last years summer, but didnt do it the year before that. Hell it even did it during the winter just gone, only needs temps of ~15C and be sitting in the sun for around 20mins minimum for it to get this vapour lock problem. Seems to be worse with premium fuel?

Any ideas? Has anyone yet discovered what causes this, from what I understand this is pretty common? Yet no one knows how to fix it.

Thanks in advance.

EBXR · 11-07-2003, 09:28

Hey Martin,

Autoco in Phillip ran an ad on TV recently, about being fuel injection specialists and one of the items they identified in the ad was the black cloud out the exhaust...

Might be worthwhile having a chat???

EBXR · 11-07-2003, 09:30

http://www.autoco.com.au/text/fuel.htm

'92BigBronco · 11-07-2003, 11:28

Premium fuel is less volatile and has a higher vaporization temperature than lower grade fuel, making it less likely to cause vapor lock....... which makes me think it's something other than vapor lock.

Assuming it's fuel injected, do an engine off static pressure leakage test to see if one of the injectors is leaking enough fuel when shut off to flood out one cylinder. The engine off pressure is normally higher than the engine running pressure is.....and a fuel rail full of 40 psi fuel can flood out a cylinder in a hurry if one of the injectors is leaking.

Other than the injectors, I'd say a headgasket. A bad headgasket can allow just enough coolant into the cylinder to cause a hard start without causing any overheating problems. A chemical block test should tell the tale on that one.

Soxx · 11-07-2003, 13:55

Doesn't sound like vapour lock to me either.
Leaky injectors sounds closer.

Next time you think it might be difficult to start, press the throttle half way to the floor and wind it over.

Rick.

NZ · 11-07-2003, 15:39

What is Vapour Lock anyway?

'92BigBronco · 11-07-2003, 16:58

Vapor lock is when the fuel inside the line boils, causing the liquid fuel to become a vapor. The vapor pressure of the trapped vaporized fuel prevents the liquid fuel from the tank from flowing through the line to the carb or injectors.

With most late model FI cars, the high pressure pump is in the tank....meaning the fuel is flowing from the tank to the injectors at around 30 psi depending on the vehicle. This makes it NEARLY impossible to boil the fuel and cause vapor lock because the boiling temperature of any liquid increases as pressure acting on the liquid increases. The higher the vaporization temp of the liquid, the less likely it is that vapor lock will occur.

Martin · 11-07-2003, 19:02

Thanks guys

Injectors were reconditioned less than 5000kms ago, and it made no difference to this problem.

As for headgasket, well I havnt needed to top up the coolant in around 15000kms since I last changed it.

sleepwalker · 11-08-2003, 06:19

u said u did some work on the car b4 it started couging. what did u work on?

TopGhia · 11-08-2003, 10:35

If all else fails, change your brand of petrol. A tank of Caltex Vortex works wonders.

cheers