Explorer Hybrid? On dash Fuel Pump ON/OFF switch. Can this do any damage?

[mawrazen]

I have been experimenting with an interior mounted fuel pump disconnect. (On/Off switch)

I have located the power wire from the underhood Fuel Pump relay (14 gauge green/yellow wire) and inserted an On/Off switch to turn off the fuel pump when coasting. (Foot off the accelerator)

The theory behind this experiment is the tranny in Drive transfers the trucks inertia to the motor and keeps the motor turning at speed untill the vehicle slows down.

After testing I found the vehicle will always refire unless I let the engine drop below 500 RPM.

In testing I would turn off the fuel pump while coasting downhill or coasting to a stop. I would then turn the fuel pump back on when the truck falls below 1000 RPM.

In one test I let the RPMs drop below 500 before restarting the fuel pump and the truck almost didn't refire. So I have found 500 RPMs to be the threshold at which the inertia of the slowing truck will still refire the engine.

What harm could cutting off the fuel pump while coasting do?

My next step is to attach the FPD (Fuel Pump Disconnect) to the gas pedal to turn Off the Fuel Pump while coasting and On (refire) when the accelerator is pressed. This concept would work well at speed but at a light or at a stop this concept would not restart the vehicle. (RPMs at 0)

The next step would be to wire a circuit to restart the engine in Drive when RPMs are at 0 and the gas pedal is pressed.

I have also considered building an APU (Auxillary Power Unit) that would maintain 500 RPMs when the truck is in drive and the Fuel pump is OFF (Foot off the accelerator)
Possibly a 12 or 24 VDC or compressed air motor that could maintain 500 RPMs when no fuel is flowing to the engine. This would keep all of the accessories in their proper running mode. (Air conditioning, power steering, brakes etc.)

I have considered modifying an Air conditioning compressor with clutch to maintain 500 RPMs using a DC motor or a compressed air motor.

APU (Auxillary Power Unit) Circuit:

(If Tranny = Drive and Fuel Pump = Off then APU = ON)

Another possible solution would be a circuit to restart the truck when the gas pedal is pushed.

Hydrid Restart Circuit:

(If Tranny = Drive and RPMs = 0 and gas petal is On (depressed) then Fuel pump = ON and starter = On for 1 second )

I dont want to burn out the starter but that seems to be a possible built in solution. This circuit would recognize the truck is in Drive and the RPMs are at 0 the starter overide circuit that would restart the truck when the gas petal is depressed.

Am I crazy or could this work?

 

[CDW6212R]

I doubt that you will accomplish much fuel savings, and the wear on the start circuit is critical. I deliver mail, and avoiding shutting off the engine is more important than gas savings. Reliable starting is worth a little fuel.

The fuel used it idle is insignificant, and the energy you may use to substitute air will be comparable in cost.

I admire the effort that you are willing to put forth, but I believe that other things are more constructive. Do the many other common things for efficiency before trying new ideas. Dream of them, but put them last after proven methods. Regards,

 

[BrooklynBay]

There are some vehicles which use an alternator/starter as a single unit, and do what you are describing. Don't do it with a regular starter. The alternator/starter doesn't have a throw out gear to mesh with a flexplate like an ordinary starter. Check this link for more information: http://delphi.com/manufacturers/auto/hevevproducts/isgs/

 

[mawrazen]

Einstein was called crazy too! Now we call him a genius.

Actually I am trying to avoid using the starter to restart the motor. I am actually looking for a way to restart the motor using an APU (Auxiliary power unit) with a DC motor or compressed air etc.

If I can built an APU that can start the truck my next step would be to use it to power the truck. I have also considered a 2nd Auxiliary flywheel that can be engaged or disengaged from the motor via a spring-loaded (to ensure contact) mechanism to the existing flywheel or driveshaft. This would allow me to charge the Auxiliary flywheel at speed (max RPM) and disengage as the truck slows down.

Upon restart condition the stored energy of the Auxiliary APU or flywheel could be used to restart or power the truck.

If this works I would eventually want the APU or flywheel to power the systems on the serpentine belt and maybe even through an air compressor provide vacuum to the Brake booster.

If such an APU can be created via a small 2 or 4 cycle engine etc. I could bypass the engine and have a connection directly to the driveshaft. This would allow me to only use the engine to charge the APU reserves (Batteries, air tanks, etc.) and only run when needed. (EX. going uphill or on the highway) In the engine off position. The APU could provide forward motion until its energy reserves are depleted or the workload exceeds whats available by the Auxiliary power unit.

In a perfect world the APU batteries or airtanks could be charged at home providing enough energy to power the truck on a short local trip. This system would allow the engine to be shut off in low power situations and refire when needed to power the truck and the Auxillary energy storage system (Batteries, Compressed air tanks, Flywheels etc.)

The next step would be to add regenerative braking capability. This could capture the energy lost as heat (friction) and convert it to potential energy using motor/generators, flywheels, Air compressors or even springs. Under an accelerator depressed situation the stored energy in the Springs, Batteries, Air Tanks or flywheel can be released be used to convert stored energy to actual work(motion) to power the APU and move the vehicle.

In this situation the engine would power ON when the APU energy reserves are depleted and would power the truck and recharge the APU reserves. (Shutting off when the systems are fully charged)

My hope is that someone will design a system that can recycle enough energy from the existing engine to allow it to shut off a percentage at a time. (DIY Hybrid)

If an APU can be created with enough reserves, aldive could cover his hood and roof with solar panels and charge his truck anytime its sunny. I'm sure he'll be the first to get 40 MPG in an Explorer.

This is all just food for thought to get a discussion rolling on a DIY hybrid system that can be applied to any stock combustion powered vehicle.

Billy Joel once wrote :
"You may be right
I may be crazy
But it just might be a lunatic you're looking for
Turn out the light
Don't try to save me
You may be wrong for all I know
But you may be right

Keep it real!

Your thoughts and feedback are greatly appreciated!

 

[mawrazen]

Brooklynbay, Thanks for the link. Thats exactly the type of info I'm looking for.

I may think I Know-It-All, but there is always someone out there that can teach you something.

 

[BrooklynBay]

There is already an air car in existence. It was a French design. Here is some information on it: http://en.wikipedia.org/wiki/Air_car. BTW, an air powered engine could run on steam, and vice versa. A man named Robert Green which lives in California is one of today's experts on this subject. Check his website: WWW.GreenSteamEngine.Com. The .Gifs run a little slow in most browsers except for Opera. You could download it from WWW.Opera.Com.

 

[aldive]

I doubt that you will accomplish much fuel savings, and the wear on the start circuit is critical. I deliver mail, and avoiding shutting off the engine is more important than gas savings. Reliable starting is worth a little fuel.

I turn my motor off whenever I have to stop for more than 15 seconds. Have been doing this for years and have had no starter issure ( still using, at 143k miles, the original starter ).

The fuel used it idle is insignificant, and the energy you may use to substitute air will be comparable in cost.

Not really,; the fuel used at idle is wasted.

 

[CDW6212R]

I turn my motor off whenever I have to stop for more than 15 seconds. Have been doing this for years and have had no starter issure ( still using, at 143k miles, the original starter ).




Not really,; the fuel used at idle is wasted.

I do turn off my truck at long stops, but I choose a time period of more than 30 seconds. I could shut off my truck probably twenty more times each day, in addition to the 20-40 times I already shut it off for stops. There is such a thing as pushing your luck, so limit the starter uses to some extent.

 

[mawrazen]

The reason I am experimenting with the Fuel Pump Disconnect is actually to create a situation where the engine is still turning allowing for power steering and power brakes. I have been using neutral gear to coast for some time. But when you turn off the engine you lose all power to the trucks sytems.

On I-77 South in VA at MM 7 you can actually coast for 7-8 miles all the way into NC. The elevation drops about 2200 ft in that stretch. The engines RPMs drop from 2500 to about 700 at 75 MPH. You actually have to use the brakes at times to keep it below 85 MPH.

I have actually shut the truck Off (0 RPM) for brief periods going down hill or coasting to a stop but you instantly loose the power steering and eventually the power brakes when you shut off the engine. This creates an unsafe situation. "hypermileing?" Also when the light turns green you have to time it just right when restarting the truck or you look really stupid. Dee Dee Dee ........ "1 out of 3 is Dee Dee Dee!" Carlos Mencia

I am trying to create automatic Hypermilage thus the need for an APU to keep the engine turning or to restart it. Brooklyn Bay and Delco have already thought of this.

Many thanks. Keep you comments and criticism coming!

 

[mawrazen]

Video! Truck runs on Propane! With Fuel Pump relay removed!

Here is a video I made powering my 1994 Explorer with a mini camping size propane can!

This experiment was able to power the truck at idle. This could be a Possible Alternate Fuel source to gasoline. It would not accelerate but did keep a steady Idle for over 5 minutes until I saw the Propane tank was freezing and I got scared.

:fire:

 

[IZwack]

Swap in a manual transmission -- I neutral and turn off the engine all the time on my Civic. Just be aware that you only get one so pumps of the brakes

 

[explorerhot]

With all your knowledge, maybe you can rig a cylinder shut off mode and turn of 2 or 3 cylinders on the highway or coasting. GM does it, and some old guy on you tube did it on an escort or turus and claimed 40 or 60 mpg.

 

[BrooklynBay]

Here's another article that you might find interesting: http://www.walletpop.com/article/_a...z/125204?icid=200100125x1207494391x1200383341

 

[seth247]

variable displacement shouldn't be too hard to do. Just need to kill the injectors. And maybe the spark. And somehow fool the oxy sensor.

 

[MrWizard]

Gas Savings, or not

Interesting discussion! My two cents worth:

- Probably not necessary to manually shut off the fuel flow on a long
downhill coast. EEC-IV shuts off the fuel after a few seconds, as
long as you are still in Drive. You actually are getting worse mileage
by shifting into neutral in this case, as the fuel is not turned off
when you coast in neutral.

- Idling at 680RPM consumes about 0.49 gallons/hour in a '94 explorer.
Restarting consumes about "15 seconds" worth of fuel.
(I dunno beans about starter life.)

- You might find the operation of the older Saturn Vue mild-hybrid
Belt-Alternator-Starter system interesting reading. A really el' cheapo
hybrid using a motor/alternator belt drive system. Probably the easiest
homebrew system. The belt limits how much power you can put back
into the system, but it's dirt cheap.

- I think for cylinder deactivation to really save much gas you have to
use some kind of lifter mod to block the intake and exhaust valves
from opening to reduce the pumping losses. Otherwise the active
cylinders just have to work that much harder to push the air in and
out of the dead cylinders. Although there is a minor savings even
without the lifter mod.

- (If you have a lot of free time) you can make a simple fuel flow
measurement system with a resistor, a couple of diodes, and a
laptop computer. You record the fuel injector pulses as "audio"
and then use any audio editor program to measure the duty cycle
and calculate the fuel flow. Or spend a hundred bucks on a
Scangauge, if you have a OBD-II (1995+) vehicle.

Okay, I better shut up, I'm starting to show my geeky side....

 

[mawrazen]

With all your knowledge, maybe you can rig a cylinder shut off mode and turn of 2 or 3 cylinders on the highway or coasting. GM does it, and some old guy on you tube did it on an escort or turus and claimed 40 or 60 mpg.

My research shows the firing order on a 1994 Exploder is:

3-4
2-6
1-5

Is this correct?

Any suggestions as to which cylinders I should disconnect?

I will try experimenting by pulling the leads to 2 or 3 of the fuel injectors to disable the fuel from being injected into the bypassed cylinders.

If I can keep a stable idle with only 3 or 4 cylinders I will report my findings.

I will try buiding a switch to create a variable cylinder fuel injection system.

Any ideas? Is this the right approach?

I hope to have some data later today.

Thanks for the feedback!

 

[seth247]

You can't just yank the plugs for the injectors. The o2 sensor willread really lean and dump fuel into the remaining cyliders and flood the engine.

 

[mawrazen]

Does Fuel Pump turn OFF while coasting in Drive?

Interesting discussion! My two cents worth:

- Probably not necessary to manually shut off the fuel flow on a long
downhill coast. EEC-IV shuts off the fuel after a few seconds, as
long as you are still in Drive. You actually are getting worse mileage
by shifting into neutral in this case, as the fuel is not turned off
when you coast in neutral.

EEC-IV shuts off the fuel after a few seconds, as long as you are still in Drive

Is this true? Where does this information come from?

In my testing, I have found that while coasting in Drive, my Air/Fuel gauge will still fluctuate from red to green (O2 sensors, On/Off signal to the PCM)

In neutral, with the Fuel Pump "On", I have seen the A/F guage drop to Red (minimum) or even go dark.

With the Fuel Pump Disconnect (FPD), when I manually shut off the Fuel Pump, the A/F gauge will go to min. or dark while coasting in Drive.

The A/F guage measures the leanness or richness of the exhaust gases.
My tests seem to indicate that fuel is still supplied to the engine while coasting in Drive. (Fuel Pump On)

When using the FPD, I need to turn the circuit back (ON) before the RPMs fall below 500 or the inertia through the tranny will not refire the truck. (Requiring putting the truck in Nuetral and doing a manual starter refire)

Thanks for your Ideas they are very helpful and informative.

 

[mawrazen]

Pulling Fuel injector actuator (signal) wire! DIY Variable cylinder engine.

You can't just yank the plugs for the injectors. The o2 sensor willread really lean and dump fuel into the remaining cyliders and flood the engine.

I pulled the Injector wire off the # 2 cylinder (Easiest to get to) running the truck on 5 cylinders for about 30 miles.

It ran a little rough and lost some power, but did not trigger a CEL.

It did seem that the truck was running richer on 5 cylinders than on 6 based on the dash mounted Air/Fuel Gauge.

There is a Fuel Flow Meter available for boats to monitor the amount of fuel (in real time) being used by the engine. This gauge is about $200-300 and has a sending unit to show the flow in Gallons Per Hour (GPH)

 

[seth247]

narrowband air fuels are not usefull for doing this kind of fuel modification. definatley need a wideband to make sure your not doing permanent damage to the engine.

Best solution: BUY AN ESCAPE.

And when you say injector wire do you mean injector wires?