I just did mine (on another thread on here) and I am amazed that there are bare electrical connections in the tank on the pump. Then you are to cut the old wires and crimp on new ones. Does anyone else find this dumb? I crimped the crap out of my solderless connectors but I will always be worried about them coming loose. Just seems if one wire touches metal the whole rear of the car will go bye bye and you could be seriously hurt. food for thought I guess.
anyone else find installing a new fuel pump a little stupid?
- Thread starter old_blue
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Keep in mind that gasoline itself doesn't burn, only the vapor, and it needs oxygen to burn. Almost all EFI pumps are in-tank. But yes, if they were to touch each other, it would short.
88gt
Founding Member
It seems insane that the wiring for the pump inside the tank is so poorly done. I guess that they hoped was that the air/fuel ratio in the tank would be so rich that it wouldn't ignite if the wiring did short out. Small comfort...old_blue said:
Yeah, you are not in any danger, even if it does short out. An auto tech professor explained the theory to me once in a class I was taking, but basically because there is so much fuel, very little vapor, and little oxygen, the elctrical current has not effect on the gasoline and it's perfectly safe.
tunedin302
I AM the law!!!
I always wondered the same thing but if fastfox is correct then that explains it. Still, a little wire insulation would make me feel better. 
Aliate X
Member
fastfox86 said:
Its the same idea of throwing a match into a bucket of gas. The match will go out.
795.0pacecar
lover of pudgy polygamists
If it bothers you, insulate the connections. No big deal. I've never heard of a mustang exploding because the fuel pump wires failed.
Blakthorn said:
It's actually designed like that and perfectly 100% safe. Ford is not the only manufacturer that does pumps like that. Other makes are the same way.
Gasoline isn't explosive, only it's vapors are. How explosive all depends on the vapor concentration inside the tank. The concentration in relation with the oxygen content needs to be perfect and inside it's just way too high. You could rip up a propane grill ignitor in there and let it fire all day and it will never blow. The concentration level favors a situation where there is slightly more oxygen. The gas filler neck in combination with the charcoal canister setup (which a lot of guys on here remove for reasons which are beyond me) keep the mixture safe. The only real chance of explosion with the setup is when filling your tank and the excess vapor is displaced outside where it combines with oxygen and dilutes to a situation where a small spark from static electricity would set it off.
There are names for those situations
Upper Explosive Limit (UEL) - The upper explosive limit in air measured by percent by volume at room temperature. The maximum concentration of gas or vapor above which the substance will not burn or explode. Above this concentration, the mixture is too "rich" to ignite or explode.
Lower Explosive Limit (LEL) - The lower explosive limit in air measured in percent by volume at room temperature. The minimum concentration of gas or vapor in the air below which the substance will not burn or explode. Below this concentration, the mixture is too "lean" to ignite or explode.
Basically...the vehicle fuel tank is designed to be a UEL environment. Gasoline has an LEL of 1.4%, a UEL of 7.6%, and the tank levels are MUCH higher than 8%...if i had to guess 80-99% concentration
Upper Explosive Limit (UEL) - The upper explosive limit in air measured by percent by volume at room temperature. The maximum concentration of gas or vapor above which the substance will not burn or explode. Above this concentration, the mixture is too "rich" to ignite or explode.
Lower Explosive Limit (LEL) - The lower explosive limit in air measured in percent by volume at room temperature. The minimum concentration of gas or vapor in the air below which the substance will not burn or explode. Below this concentration, the mixture is too "lean" to ignite or explode.
Basically...the vehicle fuel tank is designed to be a UEL environment. Gasoline has an LEL of 1.4%, a UEL of 7.6%, and the tank levels are MUCH higher than 8%...if i had to guess 80-99% concentration
At least Ford had the common sense to use METAL fittings for the supply/return/vapor lines going into the tank, as opposed to those ridiculous PLASTIC fittings you find all the time on Mopar junk nowadays (and some GM stuff). I dunno how many times I've had people coming in to plunk down $300 on a whole fuel pump assembly because some stupid little "quick disconnect" plastic fitting got brittle and snapped off the top of the sending unit when they were servicing it for something minor like a leaky tank O-ring seal or something.
Really, I've found over the years that Ford has a lot more mechanic-friendly ideas thrown into Foxes than a lot of other cars. A few annoying things here and there, sure - like the PCV valve way back yonder, or the special little stupid tool needed just to undo two screws for an ignition module - but all in all, their mechanical engineering for the Fox was pretty sound. Exposed terminal connections for an in-tank pump are found on almost every single make of pump I've seen, excluding the goofy one-piece assemblies that almost all the new Ford, GM, and Mopar cars are starting to go with, nowadays.
Really, I've found over the years that Ford has a lot more mechanic-friendly ideas thrown into Foxes than a lot of other cars. A few annoying things here and there, sure - like the PCV valve way back yonder, or the special little stupid tool needed just to undo two screws for an ignition module - but all in all, their mechanical engineering for the Fox was pretty sound. Exposed terminal connections for an in-tank pump are found on almost every single make of pump I've seen, excluding the goofy one-piece assemblies that almost all the new Ford, GM, and Mopar cars are starting to go with, nowadays.
Lemonade
Founding Member
