A quick jerk, and off I go! (Fuel inertia shut off?

[wacorider]

Hello guys an' dolls,

93 ford Ranger, 299,330 miles, second owner of a stock truck.

Just read a very informative article by another Ranger man, an engineer, here on the site, about the Fuel Cut-off/inertia switch...

....with that in mind, my symptoms: going down the Interstate and hit a high seam in the roadway, or a dramatic pothole, and the truck's power will stutter/pause, for just a fraction of a second, and then I continue down the road. been doing it for well over a year. All ground wires appear intact. battery secured. generally well taken care of vehicle.

Any ideas?

Thanks, Doug B

 

[Mark_88]

It certainly could be the inertia switch because I had similar symptoms that cost a lot of money to try to fix...only to find the inertia switch was fried...I've only posted this about a few hundred times but I never tire of telling the tale because if I had read one of my posts before this happened it wouldn't have happened...or something like that...

Anyway...pull the inertia switch off the place where it is mounted and have a look at the back side to see if there is any melted plastic...even sniff it...as some smell like...oh, never mind...if it was burnt you'd know.

It doesn't cost much to pull one of these at the junk yard and keep it as a spare...or swap it out right away to see if it clears the problem up with small bumps...if so...maybe pick up another one because they can go out rather abruptly.

You can also bypass the switch in emergencies so the the fuel pumps will keep working until you can get a replacement...but remember...this is a very important safety feature to prevent explosions and fires in accidents...

 

[oldyellr]

https://youtu.be/WDfcSAFri_Q

 

[RonD]

Also tap the inertia switch while engine is idling, see if it reacts.

What engine do you have?

Could be TFI module or coil power, again try wiggling those wires while engine is idling.

Fuel pump relay's coil could be getting weak and opening when you hit a bump, cutting power to pump.
Tap on it with engine idling