What did you do to your X1/9 today ?

johnph said:
I had a Mercury Sable wagon with this kind of inertia switch. On that car, the switch was mounted in the right rear quarter panel just 1 foot forward of the bumper. I worked as an auto insurance claims adjuster for years. Several times, customers reported to me that they were in a minor rear end fender bender (just a scratch on the back bumper) but their car would not start and had to be towed to a mechanic. If that happens to you, just press the red button and continue your journey.
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For a number of years I used to get a new Sable wagon every year as a company car. In the earlier years, I had the experience of that switch getting tripped by going over big but not huge bumps. On two of the cars, I believe they changed out the switches because they were too sensitive. Never had an issue with the later cars so I guess the problem with the switches was resolved.
 
2 ways to look at this.
If you believe in Murphy's Law with respect to electrics, adding more items to a circuit increases the possibility of that component failing. My 1979 Lancia Beta Z had an oil pressure triggered switch in the (fuel pump?) circuit. It was there so if you ran the engine out of oil, it would shut off the engine. A Lancia mechanic told me that since that 'safety circuit occasionally malfunctioned, it might be a good idea to simplify and bypass that safety device.
If I remember correctly the fuel pump safety switches came into use about the time of fuel injection. Fuel injection requires high pressure pumps and the chance of high pressure gas spraying. I do not remember these being in use as OE on carbureted cars? Perhaps it is to comply with NHTSA new car crash test requirements.
 
Electric yes, it makes sense to do so. It’s a simple safety device that will cut the fuel in case you are incapable of turning the ignition off due to an accident. I don’t see why you wouldn’t fit one. 🤔
 
NEG said:
Electric yes, it makes sense to do so. It’s a simple safety device that will cut the fuel in case you are incapable of turning the ignition off due to an accident. I don’t see why you wouldn’t fit one. 🤔
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On the '74, there's no stock electric fuel pump. Some have suggested installing one for quicker starts after the carb's been sitting for a few days. I guess if you were to install said pump, then this is a good idea to install with it...
 
Yesterday fitted the rear bumpers, haven’t managed to fit the R/H front yet as I have an issue with the sidelight/indicator unit on that side. At some point water has sat inside it corroding the contacts and creating a high resistance...I’ve had to find a replacement plus the wiring on that side is badly corroded.

 
I've never added a impact safety switch to any of my cars, and I'm still here. Definitely personal preference, I just don't feel it's needed. Obviously everyone must decide for themselves. But I do agree with @johnph, my understanding is the concept originated in conjunction with the high pressure, high volume fuel pumps used on EFI vehicles. Anyone have info on the actual history of them? However I still don't add them to my EFI converted vintage vehicles.
 
For anyone thinking of adding this inertia switch, please keep in mind that this switch is not designed to take the electrical loading of the fuel pump itself. It must be wired between the 12v ignition source and pin 86 of a conventional fuel pump relay.
 
tvmaster said:
Are these only necessary if you decide to install a fuel pump?
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TV, you already have a fuel pump. As someone stated above, if you have fuel injection, you have a high pressure electric pump on your car.
If you want your old car to meet a certain New Car safety standard, you can. Just remember that once you have installed this, if your car won't start, do not forget to hit the red button. Why? It is probably not in the Fiat shop manual diagnostic guide and not in the owners manual. On my 93 Mercury Sable, I think there was a sticker on the switch that said something like "fuel safety switch: please consult owners handbook".
 
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johnph said:
TV, you already have a fuel pump. As someone stated above, if you have fuel injection, you have a high pressure electric pump on your car.
If you want your old car to meet a certain New Car safety standard, you can. Just remember that once you have installed this, if your car won't start, do not forget to hit the red button. Why? It is probably not in the Fiat shop manual diagnostic guide and not in the owners manual. On my 93 Mercury Sable, I think there was a sticker on the switch that said something like "fuel safety switch: please consult owners handbook".
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An ‘electric’ fuel pump?
 
jimmyx said:
I've used this switch on numerous builds and have one on my K20 swap. About the best inertia switch out there. I would give some thought to mounting it in a more accessible location in case something trips it. Somewhere in the rear trunk works well as does the inside of the spare tire compartment if you want to hide it.
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In the process of fabricating the mount it occurred to me the placement and orientation in particular might matter. First, studied the switch knocking it about to figure out how it worked and sensitivity to tripping. You can feel the mechanism work bouncing it off the tool bench. Then did some research and found this, which you may find of interest. Seems like (1) you want the red button facing up (2) it should be securely mounted (3) in an accessible location. This post was from a Ford forum:

"FYI, they are direction sensitive. Upside down isn't good.

How they work: there is a small funnel shape with a magnet at the bottom. A ball bearing rests in the funnel held in place by the magnet. There is a big flag on top of the funnel that goes to the trip switch.
When you take a hard hit from the side the ball is knocked off the magnet and ramps up the funnel tripping the switch. Also a hard roll over will just lift the ball off the magnet and trip the switch. But a hard hit from the bottom (hitting a pothole) pushes the ball into the funnel not tripping the switch. A side hit while upside down will have gravity pulling the ball so it is more sensitive.

There is a reason why the trip switch is on the top. "
 
An ‘electric’ fuel pump?
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Our carbureted X's were equipped from the factory with mechanical fuel pumps. Injected cars came with electric pumps. Your car may have been modified at some point with the deletion of the mechanical pump in favor of an electric. My car was, I switched back to the mechanical pump purely out of personal preference.
 
mlsceo said:
This is more about what I did "with" my X1/9 than to it. Ran a 220 mile road trip yesterday. Highways 198 and 25 in central Ca. Some of the best X roads out there. Car ran great, great weather, good times.
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If I remember correctly, 198 between Lemoore & Coalinga was a very windy road, indeed. Just need to let the fog clear before a run at this time of year....
 
Got lucky, had no fog this time. Run 198 west to just before state 101 and take 25 north to Hollister. I run this on my GS1100E Suzuki and E63 AMG Mercedes also. First time in the X, highly recommended.
 
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My memory is fading...… Looking at the map, the curves start shortly before Coalinga and go for a while after. It was back in 71 when I was stationed at Lemoore. Back then they had "raised" reflectors in the center of the road and at night they looked like an orange snake curving in front of your headlights on 198. I had never taken the road to Hollister. 41 down to Morro Bay might be another good one to take.
 
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