Our 95 ford van vapour locks every time the temp outside gets warm (ie. above 25deg C). Are there any fixes for this? All the mechanics around here say that is just what fords do and there is no way to fix it. I believe it has a 5.7L engine.



Last edited by Rocketman at July 03, 2002, 07:33am

Rocketman: I didn't think that a fuel injected engine would vapour lock but I could be wwwwwrong. Dino

The only thing I can think of is check to make sure the gas tank is venting properly and not causing a vacum in the line.

I had this problem with a ford van. *It turned out that it had a external fuel filter under the hood. *Someone replaced it with a metel one that wasnt right for it and it vapor locked on me. *I relocated it to the frame under the van and the problem stoped. *

However i would first look into other possibilities like the last poster said, But also check the fuel pump. *And dont listen to all the mechanics that say "thats what all fords do." *I dont like ford much but im sure when they built the van it was tested and drivin in temps higher then 25C.

Rocketman,

Give us more info on what it does, I find vapor locking on an EFI rig like this to be very unlikely......fuel under high pressure is very difficult to "boil" which is the cause of vapor lock. I am an ASE master tech, and I have worked for a company who had a fleet of these, and I can say I have not seen vapor lock on any of these, exact symptoms, temps, etc.... may help point you in the right direction. I will check my tech service bulletins as well.

I agree with slarson.that is why most efi cars do not vapor lock the higher the pressure the higher the boiling point.check fuel pump and find something good to insulate the fuel line.

Well, what will happen is when driving in temperatures, usually 30deg C (86 F) the van will lose power, eventually stalling itself. Then it won't start unless you let it sit for a while. And even if you get it started again, you have no power. It will not even idle.

* The only way to get it back to normal is to let it sit for like an hour or more. Then you will have normal operation. But not for long, as it will lose power and stall out again.

I guess I should also mention that all gauges read normal while this occurs, and it happens more often when on the highway than driving in the city. It actually went down here in town just last thursday when it was about 90-95 F



Last edited by Rocketman at July 03, 2002, 5:49pm

It could be.

1. Fuel Pump.
2. Fuel Filter.
3. Fuel Resistor.


Thats all i can think of. *Wait till slarson checks the service bulletin, maybe its common.

Rocketman,

Here goes.....the first things I would verify the fuel you are using meets the manufacturers recommendation, Ford has a bulletin #98-26-2 for "fuel volatility concerns"...the problem centers around fuels formulated for cooler weather being used in elevated temps, if you get fuel at the same place all the time, change stations and brands and see if you can find one that clears it up, or if you get the fuel from a storage tank that is only filled 2-3 times per year, you could have winter blend fuels on hand....the other thing is use the recommended octane, high octane fuels are more volatile. Basically the more volatile fuels like winter blends are more volatile (they evaporate at lower temps) and they cause fuel pump cavitation or "vapor lock". Sometimes simply filling the tank will stop it, see if these things help. Next if the problem persists I would have a fuel guage hooked up while driving enabling you to watch the pressures to see if they drop when the problems start, if they drop, it could be the pump, "vapor lock", electrical circuts, regulator etc...if the pressure remains ok, it could be an ignition problem or even a computer/sensor or control problem. Remember, cover all of the basics first, things like tune up, check engine light etc....look at hings like are you smelling gas? is the exhaust plugged?(cat. convertor) does the exhaust glow red? has the fuel mileage dropped?

It could be so many things, but look and watch carefully, it can tell you alot.

It's not the fuel, because that van is filled at many different stations, in many different towns. It consistently breaks down when the temperature gets higher than 25C. It just loses power and dies.

Rocketman: i have a 87 iroc tune port injected and it did *exactly and i mean exactly the same thing 3 times in the 13 years i have owned it.
the problem every time was the feul pump.
I am not saying this is your proplem but could be a place to start.
For me it always happened when the out side temps were very hot and it happened slowly. You could feel the power slipping away then it would start to miss a bit then not long after it would die for about an hour. start it up and it might last another hour or a few days.
replaced the pump and was good for a few years.

Rocketman,

If it was mine I would install a fuel pressure guage in the thing and see if the pressure drops before or as it is conking out, route the fuel pressure guage so you can see it as you drive it or have your mechanic do the same thing, it is possible that it may actually be something else, but this will verify wether or not it is fuel system related.

I have a '93 F-150 with a 5.0L engine that has gone through a couple of igniton coils and that was how it acted before it died, another thing to check would be the ambiant air temp. sensor, if you have an Auto Zone store in your area they will hook a scan tool up to your vehicle for free, at least they will in my area.