Hello, I had my cel come on the other day so i brought it to the dealer and they told me the fuel system wasn't presurized. How do i go about fixing this? The mechanic told me to start by replacing the gas cap, is this correct? I've never heard of that befor, what do you guy's think? Thanks - Johnny

 

JBG
Was it just a cel or was it running funny??? if your fuel system was completely depressurized it wouldn't run at all. sometimes if the fuel cap is even slightly ajar and the computer has to run the fuel pump harder than it normally does to maintain pressure it can trigger that code. My wife has a habbit of not replacing the gas cap completely a LOT!! First just make sure the cap is on tight and see if that does it. Probably will. If it isn't running properly you probably have bigger issues and will need to provide much more info to diagnose it.

Hope this is it!

 

johnny be good,
The EVAC system is maintained at 1mm/hg vacuum to prevent gas fumes from escaping into the atmosphere (emissions). There will usually be no poor running problems since there is a restrictor under the hood that prevents you from dumping vacuum by only allowing 1 mm/hg past the valve. This is not part of the pressurized fuel system.
If there is no vacuum for a prolonged period of time the CEL will light up to let you know. The first place to start is replacing the gas cap. If that doesn’t work then check back here for more advice. I would advise you to get the cap from Ford even though they are more costly, the aftermarket caps leave something to be desired.
Good luck.

 

OK guys thanks, I'll start with the gas cap and see if that does it, it runs fine just has the check engine light on.- Johnny

 

just a thought? If you took your truck to the dealer why didnt you get it fixed????

 

They said it "shouldn't" take more than a few hrs to figure out what was wrong, at $50 per I thought I'd try here first.- Johnny

 

I guess I must be confused on this. You are talking fuel system not pressurizing (not too much to do with the EVAP system). Dealer is talking gas cap (EVAP system), and another member here is talking EVAC (same as EVAP system). What was the CEL code that came on? These are really different systems (fuel delivery and the EVAP system), so a code might help us help you.

 

The gas cap fixed the problem, thanks for the help guys.- Johnny

 

Great, nothing like an easy fix.