Shopsmith Forums

That fuel cut off switch or inertia switch may be located behind the kick panel in the foot well on the passenger side of the vehicle, at least that's where it was on my F-150. It's there to prevent fuel from getting to the engine in the event of an accident. Perhaps one of those pack rats got to the wire leading to the switch. If there's no power, there's no fuel to the engine. There's a button/plunger on top that resets the switch if it popped. A defective relay also is a possibility.

pennview wrote:That fuel cut off switch or inertia switch may be located behind the kick panel in the foot well on the passenger side of the vehicle, at least that's where it was on my F-150. It's there to prevent fuel from getting to the engine in the event of an accident. Perhaps one of those pack rats got to the wire leading to the switch. If there's no power, there's no fuel to the engine. There's a button/plunger on top that resets the switch if it popped. A defective relay also is a possibility.

I found and verified the switch to no avail. This does not mean that the wires are good/bad but I learned that the switch exists. I did not know of the switch until now.

reible wrote:Hi,

Just a couple of items I haven't seen mentioned yet.

One is that the fuel pump can have it's own fuse, a simple check might find that as an issue.

Some cars/trucks have a safety shut off for the fuel pump, if there is impact the switch flips, a simple reset is all that is required, well that and finding where the switch is.

On one of my cars the top mounted fuel pump was in the trunk under the matting. Not sure how that would work on a truck be it would be worth checking.

Some trucks have dual tanks and various combinations of using one tank or both tanks and or tank balancing... I had a cousin who filled the wrong tank and ran out of gas about a half hour later, bet the guy in the tow truck and a good laugh after he showed him how to turn on that tank...

BTW the fuel system will most likely not stay at pressure for long or at least that is what I've found when replacing injectors etc.

To bad we live so far apart, I have a pressure tester, rather expensive tool for the single use I've had with it. Still nice to know I have it in case we need it. Some auto parts places rent tools like this, or even loan them out if you are buying parts from them.

Ed

I have not checked the fuse panel. Better do that soon.

The inertia switch did not fix the problem. The shrader valve has not proven anything yet - except that I have dropsey. I lost the cap down into the engine compartment somewhere. Nick had dropsy, I do too.

oldc6 wrote: .....

The red plastic line which appears to be broken is vaccum to the fuel pressure regulator . That is the round thing . it controls fuel pressure once engine is running.
.......

that red line that appears broken is a critical thing because without vaccum to the pressure regulator you are running full pressure to system at all times. normally this only happens under full throttle accelerations. that broken line may have caused the check valve in the fuel pump to be broken because of to much pressure against it......

find a good tech, and he should be able to diagnois pretty quick........

He is correct. The hose to the fuel pressure regulator go that is the first thing I would fix. Buy some tubing and reconnect it if you can.

I'm not sure if losing vacuum to it gives the same symptoms as it failing, but when it fails the car won't run. I when from 70 to coasting with the engine off when mine failed.

Not sure about the comment about the check valve though.

As stated, I believe the inertia switch is OK (it is and was pushed in) and the fuel pump fuse is good.

The battery is fully charged and all of the DC functions within the camper are operational. Note: Did not check out the refer.

The engine cranks but does not fire except when shot with ether then it sounds as though it wants to start (ignition system good).

Do not hear the fuel pump in any ignition key position. Also have not found the fuel filter (need to crawl around under the rig).

Looking for a point where I can verify power to the fuel pump. It seems that there must be a quick disconnect in the line somewhere. I would hope it is back near the tank.

If there is a quick connect, I can open it to measure pump power OR I can inject 12Volts to verify pump.

If I was thirty again, I'd have this done.

I really don't want to have to drop that tank. It is full (55 gallons I think).

You might need a wiring diagram to do what you want. You will have fuel pump wires and sensing lead(s) for fuel level. Most of the units I have seen have 4 wires, but you could do it with 3 if they share a ground. (ground will be a return line due to it being at the fuel tank).

You will probably have the fuel line and a fuel return all coming out of the same plate, you could also have vent but that is more likely near the fuel input location.

Ed

I think most of today's fuel pumps are inside the tank and under the fuel so you won't hear them run. Every car/truck I have owned since 1990 have been inside the tank.

I really never liked the idea of running electricity inside a tank filled with fuel but I haven't heard of one blow up yet. Someone once told me that there wasn't enough oxygen in the tank for the fuel to burn. Hey what do I know.

I said all that to say this you can if you decide the fuel pump is the problem install an aftermarket fuel pump outside the tank and just insert a fuel pickup. Be careful how you do this since most of the time the line that supplies power to the pump is also the same line that carries the fuel level sensor info to the gauge.

On every diesel have ever seen there is a large fuel filter with a drain cock. I would think you could check there to see if your are getting fuel or not. I;m told to be careful checking for fuel on the fuel rail as this pressure can be fairly high and fuel will spray everywhere.

My advice call your insurance agent. I will bet any damage by critters is covered under you comprehensive. Comp claims usually have a low deductable and do no count as accident claim against your insurance.

Well, I finally have gotten out from under the RV. It is not as easy as it once was; they must be built on a chassis that is lower to the ground.

I have located the fuel filter, the schrader valve, the associated fuses the inertia switch and the quick disconnect to the tank.

Having found them all, I now believe I have to bite the bullet and call AAA. It was just too hard getting under there where I would have to work. In my younger years there would be no way I would pay to have this sort of work done but I might be getter wiser along with older.

The fuel filter would be a piece of cake for some young pup with the right tools; especially if it was up on a lift. The fuel tank is something else all together.

You should be able to hear the fuel pump. It will build pressure for about 2-3 seconds when you first turn the key to the on position. It should sound like a quiet hum. Might need a helper and put your ear close to the pump in a safe location.

You also might want to try your library. If you have a card they might have online access. Here is the link to the Pima County library (think that is where you location listed). They have something called the Auto Reference Center. My local likbrary has AllData, but only at the branch.

http://0-search.ebscohost.com.libraryca ... autorefctr

I be late to this discussion, but fuel pump or power to it(assuming no plugged fuel line).

Fuel pumps seem to be non-tolerant of long rest periods.

Your symptoms have been my symptoms in the past.