Leave it to Ford on this one....Inertia switch?

This post is for a relative of mine…speaking what I know about the vehicle. Trying to decide if I want to buy it or not…



2000 Ford Ranger 3.0L 4X4 extended cab. 127,000 miles. Driving down the highway at 70 miles per hour with the cruise control set. The truck started bucking and “falling on its face” like it was starving for fuel for a short period of time, then died just like the key was shut off. All the dash lights came on, the radio was stil playing, just no life in the engine. Engine would crank, but no start. Had the vehicle towed to a small garage. The “mechanic” put his scan tool on the vehicle and found several codes stored in the computer. Not sure what they were but he replaced a bunch of sensors (ie. MAF sensor, TPS, maybe an O2 sensor?) and still has no start. He supposedly got the truck to run roughly for less than a minute after he blindly put these sensors in.



Now my relative does not want to put any more money into the truck. Its been paid off for a while, and doesnt seem to want to trust mechanics any more to charge him for unnecessary work. The last time he spoke with the mechanic he said he was “90 percent sure it is a sensor down on the frame that deals with fuel”.



My relative couldnt remember what the name of the sensor was but Im thinking this must be the inertia switch. But it is most definitely not attached to the frame. Its located in the passenger side kick panel. These Rangers are well known for chewing these up and spitting them out, leaving you stranded on the side of the road if you dont know what to do.



Now the questions I would like to know is…

1. Is this logical?

2. Is this vehicle worth the $300 that im about to pay for it, not knowing what is wrong with it for sure?

3? Does anyone know if there is another “fuel sensor” on this vehicle that is attached to the frame?



Thanks in advance for your input!

I’d definitely take it to a different mechanic, this one sounds like he needs some more training. But, for $300, as long as you can find out the problem, would be a good deal as long as the rest of the truck is in good shape

Forget that mechanic. He is obviously an idiot, as you can scan the computer to get an idea of what might be wrong, but it sounds like he just decided to replace any sensor that might be bad (an “I don’t have any idea about cars, I just swap parts” person). To test the 02, unplug it. The truck will still run, just rich. To test the MAF, unplug it. Again, it will still run, just rich. TPS - that is easy to test with an Ohm meter, no need to replace it “just in case”.

Inertia switch? Possibly - (I don’t work on Fords). These kill the fuel pump power upon impact (a crash), so yes, that could cause fuel problems. But that could be verified easily with a fuel pressure gauge before tearing things up and replacing more parts.

It’s highly unlikely that an inertia switch is behind this problem.
Unfortunately, there is not enough info known to make a half-educated guess because we do not know if the problem is fuel or spark related, if there is any fuel pressure present, codes present, or the reasoning behind flinging a crate of spare parts at the problem.

Just an FYI here. Getting a computer code for something does not automatically mean that the part referred to in that code is necessarily bad. The code provides a starting point for diagnosis.

It’s difficult to give advice on this one but the mechanic should not be replacing parts en masse. This only means wild guessing.
The guy should take a deep breath and determine if fuel pressure and a spark is present. If not, then proceed to the next step in figuring out why.
At 10 years old with 127k miles has he considered the possibility of a failing fuel pump? If the fuel filter has never been changed on a regular basis the pump should be a prime suspect.

Has anyone tried resetting the inertia switch? It’s just a push button…

and besides, a simple continuity test would solve that question for you

IF the ranger is the FLEX FUEL setup, 8th digit of vin code ‘V’, there is the flex-fuel sensor on the frame.

If 8th digit is ‘U’, no sensor.

high dollar stuff, don’t guess on this one. ford # YL5Z-9C044-BA list $661.46 / common sale price $529.95. Rare to need as well. Our dealer has sold just one in the five year application span for that part.

There is a fuel tank pressure sensor but it’s on the gas tank top.
An inertia switch is either ON or OFF. no inbetween, no sometimes. Right kick panel, a good one is re-setable, a bad one can have the circuit jumped to replicate ‘on’.

AND,by the way, your nasty little dig on Ford has nothing to do with it !

$300? Unless it’s in really bad shape overall then yes, it’s abaoslutely worth $300.

This “blindly put the sensors in” mechanic just landed you a good deal. No matter what sensor (or inertia switch) it turns out to be. These items are all replaceable parts. The thing that makes a vehicle a questionable buy is when something internal to the engine or the tranny or drivetrain is failing, or the vehicle has grown old to the point that it’s no longer reliable or safe…or simply needs tons of work. I don’t see anything in your post that indicates this.

The others more familiar with this vehicle have offered suggestions that I can’t add to, but yeah, it’s worth $300 IMHO. Heck, you could spend $300 taking the family bowling and out to eat!

I think that if you want to experiment on something, you have a great opportunity. A Haynes manual and a borrowed diagnostic tool for OBD2 might get it going. You don’t have much to lose, and you have nothing to lose if you don’t buy it. You could do a compression check. The title and registration is what jacks the cost up.