Electric fuel pumps are dangerous .

[Grumpy old man]

I keep seeing multiple threads about installing an electric fuel pump that most of these new engine swaps require and some of these set ups are scary at best , Hot wiring in an electric fuel pump to your ignition won't stop the fuel flow in a crash , Even a separate fuel switch is dangerous , What I'm seeing is no concern for safety and just doing whatever it takes to make the engine run , No mention of auto shut offs , No mention of running hardlines , multiple sections of regular rubber fuel lines connecting pumps and filters to partial fuel lines , Not one mention of adding in an auto shut off , So What are some of the auto shut off options you've seen ? People are used to all the safety measures that are built into the late model cars/ trucks that they are pulling these engines out of and until your involved in a serious crash in one of these old trucks you'll be wishing you had one installed . If heaven forbid you do have a crash and go face first into the steering wheel or solid mounted metal dash an automatic fuel cut off could save your life . I understand not everyone driving these old trucks are mechanically inclined , But if you get knocked out hitting the dash your not going to be thinking I've got to turn off the fuel pump . With no air bags or crash sensors you need to add in a fuel safety shut off . Always think safety first .

[Johnl48]

I expressed this to holley tech with the sniper efi. They told me as soon as engine loses rpm its built into its system to cut power to the pump

[geezer#99]

Originally Posted by Johnl48

I expressed this to holley tech with the sniper efi. They told me as soon as engine loses rpm its built into its system to cut power to the pump

How much rpm?
No gaurentee the motor quits in an accident.

[HO455]

Originally Posted by geezer#99

How much rpm?
No gaurentee the motor quits in an accident.

There some OE systems that use RPM for pump shutdown. Some also use a shock sensor to cut off the pump(s). With any system there is the "perfect storm" scenario where the can pump continue to run. You just have to determine you comfort level.

[Johnl48]

Originally Posted by geezer#99

How much rpm?
No gaurentee the motor quits in an accident.

Not sure they said I couldn't run the oil pressure cut off switch because the EFI system runs the pump for 5 seconds before the motor starts

[72c20customcamper]

I have this on both my AMX and my Lark .

https://www.amazon.com/Carter-A68301...02672362&psc=1

[Rickysnickers]

Originally Posted by 72c20customcamper

I have this on both my AMX and my Lark .

https://www.amazon.com/Carter-A68301...02672362&psc=1

How do you wire this into an EFI system? I have a Pro Flo 4 and would like some sort of shut off.

[HO455]

I wired in a Revolution Electronics fuel pump controller. The controller sends power to the fuel pump for a couple of seconds to put a shot of fuel in the carb (or the fuel injectors) when the key is turned on. After 2 or 3 seconds it will shut the pump off if no tachometer signal is received. Once the tachometer signal is received the pump starts running again.

In addition I use it to control power to the air bag compressor via a 40 amp relay. With the compressor and fuel pump married together they will run briefly then shut off, if I pause the key in the run position before engaging the starter. I can then start the engine without the compressor drawing current from the battery while cranking

https://www.revolutionelectronics.co...Fuel_Pump.html

[LNP]

Originally Posted by HO455

I wired in a Revolution Electronics fuel pump controller. The controller sends power to the fuel pump for a couple of seconds to put a shot of fuel in the carb (or the fuel injectors) when the key is turned on. After 2 or 3 seconds it will shut the pump off if no tachometer signal is received. Once the tachometer signal is received the pump starts running again.

In addition I use it to control power to the air bag compressor via a 40 amp relay. With the compressor and fuel pump married together they will run briefly then shut off, if I pause the key in the run position before engaging the starter. I can then start the engine without the compressor drawing current from the battery while cranking

https://www.revolutionelectronics.co...Fuel_Pump.html

I use this same controller. It will make your fuel pump do exactly as it does in todays car/trucks. If in a wreck and the engine died the controller shuts off the pump. You can use it for fuel injection or carb. If you got the key on listening to tunes your fuel pump isnt running.

[Johnl48]

Originally Posted by LNP

I use this same controller. It will make your fuel pump do exactly as it does in todays car/trucks. If in a wreck and the engine died the controller shuts off the pump. You can use it for fuel injection or carb. If you got the key on listening to tunes your fuel pump isnt running.

I believe this is basically what's built into the Holley sniper efi

[72c20customcamper]

Originally Posted by Rickysnickers

How do you wire this into an EFI system? I have a Pro Flo 4 and would like some sort of shut off.

Neither have fuel injection but I'm sure if you wired the tank pump to it it would work .

I used to get vapor lock real bad with these two cars . But the little inline 4 psi pump cured it but since i can get non e gas i dont think its necessary anymore

[jeffahart]

Originally Posted by Grumpy old man

I keep seeing multiple threads about installing an electric fuel pump that most of these new engine swaps require and some of these set ups are scary at best , Hot wiring in an electric fuel pump to your ignition won't stop the fuel flow in a crash , Even a separate fuel switch is dangerous , What I'm seeing is no concern for safety and just doing whatever it takes to make the engine run , No mention of auto shut offs , No mention of running hardlines , multiple sections of regular rubber fuel lines connecting pumps and filters to partial fuel lines , Not one mention of adding in an auto shut off , So What are some of the auto shut off options you've seen ? People are used to all the safety measures that are built into the late model cars/ trucks that they are pulling these engines out of and until your involved in a serious crash in one of these old trucks you'll be wishing you had one installed . If heaven forbid you do have a crash and go face first into the steering wheel or solid mounted metal dash an automatic fuel cut off could save your life . I understand not everyone driving these old trucks are mechanically inclined , But if you get knocked out hitting the dash your not going to be thinking I've got to turn off the fuel pump . With no air bags or crash sensors you need to add in a fuel safety shut off . Always think safety first .

And it's the first thing that should be considered... not the last. Another pet peeve of mine is all the automotive shows on TV where the grinder just gets whipped out and sparks fly, undercarriage, engine bay. But teaching a bit of safety, or common sense is not very crowd pleasing. The old Norm Abrams used to look like an old Hen always saying, "There's no important safety tip, than wearing these, safety glasses". Said as he pointed to his safety glasses. Way too boring and repetitive for today's sensational programming formats.

j

[special-K]

The factory runs the pump circuit through an oil pressure switch on the diesels I've had. I assume my gas Suburban has the same thing. Soon as the engine dies the pump stops. If the injection pump isn't getting fuel, the first thing to check is bypass the oil pressure switch back to the lift pump to see if that is working.

[Sheepdip]

A combination of an Oil Pressure Switch and Impact Switch should handle about any situation.

[pjmoreland]

I installed both oil pressure and impact switches on mine.

https://www.summitracing.com/parts/hly-12-810

https://www.summitracing.com/parts/SMP-FV7

https://67-72chevytrucks.com/vboard/...d.php?t=828999

I used this hard line kit:

https://www.sstubes.com/products/tgl...line-kit-steel

[Jason Banks]

Here's a good option. Less work than the oil pressure switch in my opinion.

https://www.amazon.com/ACDelco-D1876...dp/B000C9PBXU/

[cj847]

The thing that scares me the most on LS swaps-----rubber fuel lines. I have searched for hard lines that connect like factory. But unless you can use the fuel feed from a tahoe or other you are out of luck. I am actually starting to have concerns about people driving a 2000 ls powered vehicle. That 6-8" of rubber fuel line right at the fuel rail (directly above the exhaust manifold) is now over 20 years old. It is one thing to have old rubber holding 5-7 psi, but I am talking 60 psi in ancient rubber!. If that hose gives..........

PS> I have an LS swap that is 5 years old. The other day I looked at the hoses and nearly crapped my pants. Even though the vehicle has been in doors and I used high quality fuel injection hose it was cracked and dry rotted to the point it was scarry. Needless to say, I immediately replaced it and plan to again in 4 or 5 years (or until I find steel lines that don't have weak connections.)

PSS> If you have braided rubber lines you should peel some off and check the underlying rubber.

[LS short box]

My 98 Wrangler LS swap has almost 15 years on it. On all my LS swap I run -6 SS line. No rubber or plastic fuel lines for me although OEM's use plastic all the time. One complete length of -6 from the FFR to the fuel rail. No splices. Never had a problem but no accidents.
On a typical LS system if the ecm doesn't see a crank signal it will shut down the fuel pump.
Seems to me some folks are using a roll over/rear impact switch from a Fox body Mustang to shut off the fuel pump.
If I did roll it over onto the roof I'm thinking the fuel pick up will uncover and the engine will die in seconds.

[Grumpy old man]

Originally Posted by LS short box

My 98 Wrangler
If I did roll it over onto the roof I'm thinking the fuel pick up will uncover and the engine will die in seconds.

Wranglers are famous for rolling over , Are you willing to bet your life on it ? I'd rather go in my sleep than a ball of flames .

[LS short box]

Funny you should ask. I actually did roll a CJ5 over when I was in the army as a MP(76-79). I was driving on patrol on typical wet rainy night at FT. Lewis WA on a asphalt road going about 35 mph and met a convoy with tanks on flat beds so I pulled off onto the soft shoulder and let them pass and as I pulled back onto the road the front tire caught the edge of the asphalt and the Jeep rolled one complete roll and back up onto its wheels. The hard top and glass were toast. It was still running! My partner and I were fine. My LT wasn't impressed. It was wrote off as a "training accident".

As for my 98 Wrangler it has a roll cage unlike most street cars. Front and rear bumpers made of 3/16"x 3" x 4" tubing. Gas tank has a tip over valve in the vent line like the ones used on race cars that prevents gas from pouring out of the vent tube in the event I'm upside down. I have no doubt that if my Wrangler was upside down the fuel pick would uncover. The stock Wrangler fuel tanks have a built in sump that protrudes thru the fuel tank skid plate by about 1/2". My Wrangler left the jeep plant aa 2.5 4 cylinder so the gas tank only holds 16 gallons max. It's the same tank as a 6 cylinder jeep but the fill tube extends farther into the tank so the 6 cylinder tank holds 20 gallons. Why I no idea. But it means I have 4 gallons of room in the tank. A FI system with no fuel shuts down the engine within seconds due to lack of fuel pressure. No fuel so no crank rotation so the LS ECM shuts down the fuel pump. Not like a carb system that has a fuel in float bowl.
The 98 and up Wranglers have a wider wheel stance the has helped prevent roll overs.

I think the king of roll over SUV's were the Bronco II's of the 80's.

I would be more worried about a hard rear impact that opens up the gas tank and spills a bunch of fuel on the ground like on my current 80 Camaro LS swap project.

[Richard]

Using the factory ecm fuel pump on/off in my swap. Factory pwm pump with aftermarket pwm controller in my case. Will get the action of priming before start and other safety benefits of a stock vehicle.

[Bigdav160]

I don't see an electric pump anymore dangerous than a mechanical.

[volksworld]

bigdav160...heres the scenario...you crash the truck...its a manual trans...you had your foot on the brake but never hit the clutch in the panic...engine stalls,key is still on, something fuel related is torn up in the crash and your electric pump just keeps happily pumping gas under pressure onto the engine,exhaust,whatever ....toasty...not as easy to stall an automatic but shattering the cap against the firewall and other stuff is still possible depending on severity of the crash

[KQQL IT]

These were a handy trick to know driving tow trucks in early 90's.

Ford Genuine 5L2Z-9341-A 5L2z9341a Fuel Pump Inertia Safety Cutoff Switch Cut Off OEM https://a.co/d/7ugWHjy

[Accelo]

I find this thread interesting.
Don't get me wrong as I am a safety advocate.
We are worried about fuel safety and not a single mention of the stock fuel filler, sticking out, on the cab side and a full tank of fuel inside the cab.
Begging the question.
Isn't any rear mounted fuel tank safer in an accident than the factory set up?
Cheers