Go Back   EcoModder Forum > EcoModding > DIY / How-to
Register Now
 Register Now

Reply  Post New Thread
Submit Tools LinkBack Thread Tools
Old 08-18-2013, 06:03 PM   #191 (permalink)
Learning Aeromodding
myrefugeisintheLord's Avatar
Join Date: Feb 2011
Location: Spokane, WA.
Posts: 199

Metro - '93 Geo Metro 4 door hatchback
90 day: 35.26 mpg (US)
Thanks: 59
Thanked 45 Times in 32 Posts
The Ultragauge STILL reads mileage when the engine is off and it's saying error. This was a constant thing I saw when I was EOCing with my Auto RAV4. Before I realized that was NOT a good thing to do. One way to prove it really quick is to take note of the mileage before you kill the engine, then see what it shows when you bump start. It will be higher.

Your kill switch looks great! Way to go!

What vehicle is that? And what are you killing? Are there any more details you want to add that will help other people driving a manual of your type of car?

  Reply With Quote
The Following User Says Thank You to myrefugeisintheLord For This Useful Post:
gofalls (08-18-2013)
Alt Today
Popular topics

Other popular topics in this forum...

Old 08-18-2013, 07:34 PM   #192 (permalink)
EcoModding Lurker
Join Date: Dec 2008
Location: lone star state
Posts: 55
Thanks: 1
Thanked 2 Times in 2 Posts
what does motor off mean. (key off, spark off, zero RPM, what? , ECU oFF?)
where is that switch, connected to what.? (sorry lazy to read 20 chapters)

I guess first at , just foot off gas pedal coasting...coasting in gear?.

this is easy. (I just finished my gauge, home made)
mpg is range / flow. or distance/fuel rate per hour. miles/GPH
there are 2 ECU's made,
Type A (uses MAF PIDS to reverse calc. fuel flows) (my car, my gauge)

Type B: (ECU B, tells direct actual fuel flow (newer cars) see PID 01-5E ?

note carefull,y this is Division and dividing by zero , is illegal.. dig it?
What your scan tool does, is not known, ask the designer.... but these are facts here.

take the example of type A, MAF, my maf reads some flow, when ECU is in CUT fuel.
(ISC +idle bleed and TV fly plate leakage) known as, pumping losses.....

Less in gear coasting ,than out of gear. some cars, try it. (ISC actions)
so I get a lie. see? why? fast speed, but shows flow that is not real. as a divisor.
In cut fuel the mAF reads but ecu does not inject. so i get a small error.

Example B: real flow. (maf is ignored here)
this ecu shows ( example) 45mph /div, by zero flow.

in my software, I trap the zero flow, and change it to .0000001 so there is never a divide by zero
and shows an insane high Mpg. (if fact the MPG is UNKNOWN and huge)
in truth cut fuel MPG is not measurable at all. see why?
It's all in a nonlinear zone.

Did you know the ECU feeds fuel to the CAT, just to keep it hot , coasting?
It's like 200 mpg fuel rates.

when you kill spark , there str no injections, at all. this is a hard fast ECU rule. zero RPM. zero flow.
Fire safety regs.
and if you do that, there is no MAF reading , nor is there a PID 01 5E , fuel rate.
BTW2, if the crank spins (in gear coast'g) and the rpm is over 300 , the ecu inject or a rolling start.

and if the ECU is on, and VSS is clicking, that is say 45mph / divided by 0) div by zero is illegal.
all computers trap div. by zero. as ERROR. (mine throws, INF)
in math. it's Infinity. if i did this , i'd send 9999 mpg to the display , for the indication of INFINITY. and do.

my gauges are here, x3 see my infinity trap. is free code. all Blue tooth.
ECU Engine Simulator

tell me how do you average Infinity to real data....
and why would you..
I send that data to the byte bucket.

btw3, the first scanguage sold had the divide by zero error.
and they fix that LONG ago.
ask you self how the did that.
there are only 3 ways.
blank the display,
force zero MPG, nah that scare the kids.
do this.
if flow =0 (or ERROR,or INF) set flow to .00000001.

it really don't matter is its in a none linear range, (study how injectors really work)
like computing MPG based on Gas tank evaporation.


Last edited by jtgh; 08-19-2013 at 04:52 AM..
  Reply With Quote
Old 08-18-2013, 08:07 PM   #193 (permalink)
EcoModding Lurker
Join Date: Dec 2008
Location: lone star state
Posts: 55
Thanks: 1
Thanked 2 Times in 2 Posts
lesson 2; Accuracy, first off ,it's no instrument. it's only a toy. (but nothing better to learn to drive frugal !)
when your ECU and scan tool boots,
your scan tool does a valid pid scan, to see all valid scans.

1: if not 01 5E pid valid, the tool must use MAF reverse calcs. most older cars dont have this.
these are only accurate on a hot engine and in closed loop, and are not accurate, otherwise.
Can be very accurate, on flat ground cruise near 50mph, and never at WOT or near 75% of WOT. (if no MAF it uses the MAP)

2: if the car has 5E available and the tool is smart enough to use that? it gets fuel rates from the
core of the ECU injection rate algorithm.

This may be, vastly more accurate at all times. but not on the low end.
read how injectors work , at low rates,( not so good, is the simple answer)
the low end is a very tiny flow, at cut fuel mode.
Does, this help understand the limits for ECU OBD2 scans?
The ECU also uses the injector to keep the TWC, three way CAT hot.
If car is CALIF car , you can be sure it does. yes, this wastes fuel. but makes the air clean.
Case in point:
Here are some more facts about OBD2, 1996 to present
I have 2 examples here, a 96, Suzuki 1.6L and a 96 , ford v6 3L
they are totally opposites (book ends)
the Suzuki; if you kill the CMP (cam sensor , the spark dies on purpose.) Dead Distributor.
this is because the ecu MUST have cam location data.

the Ford keeps running. CMP cut. (it has no Distributor "DIS" system it is)
the Ford, runs off the crank sensor, it can do that magic, because, it CAN.
it has wasted spark ignition.

But the FORD goes into to OBD fault mode. P0340? and that fact
shuts down the mandatory spark misfire monitors.
and goes to limp-home, which wastes fuel. (fuel guessing mode)

I used many types of ECUs to test my OBD tools, I make.

Point 2, if you go into Fault mode, the SYSTEM can be slow to recover in to full
closed loop. after say, dumping the clutch , coasting. (bump starting)

That is because , this ECU you have , drops all the fuel trims on the floor.
It did that due to limphome mode.
Depends on year, make of car and even if car is from Calif. how it does that and how fast.
my point?. your readings will be way off. (off, dead,or pure lies)

BTW, my TI30IIS hand calculator. (brand new) shows 45mph/0 =
"Divide By 0 ERROR, on the LCD. ( nothing new under sun? huh)

on most microprocessors, this is a NMI, "non mask-able interrupt."
That means, in uCode jargon, the last math instruction was (DOA).
how you or your scan tool handles NMI is your job,.

Me ? I trap them, and use a very tiny number, to avoid all errors of this type.
mine is really, in OBD2 parlance just a 16bit integer. PID rules.
so in binary that would be B0000000000000001. (i add the LSB 1 at end)
here is 1 more, fly in the ointment.
the ECU may produces wrong numbers in the live data stream , when in LIMPHOME.
each ECU works different, Iv'e run many and they all have odd , results in Limphome.

I have a Plamer Software scan tool software, and comes with the MPG algorithm for free.
I does in fact never divide by zero, it shows about 150 mpg. coasting, in cut fuel.
and you can add in your own macro instructions an display any thing you want !

my question to you, why is 150mpg not good enough.?
That number btw is very inaccurate. on all cars. it's a huge number yes but is not accurate.
It's not because no ecu was ever designed to do that. not 1. at all times and all modes.

but does work well , hot engine, flat road , easy cruise.
and the O2 sensor fulling engaged.
on my car and my guage, i have a closed loop LED.
i keep the LED going for the longest time and MPG is MAX !

just 1 little LED, can do that.

IN the end , only the fuel tank refill , is the RAW truth. Rubber meets road.

BTW 4, be careful slowing down with no brakes (lamps), the guy behind you can eat your can.

hers is my proof, nothing new under the sun..... 84 mpg (very light car)
Has carb that my thumb cant fit into... too...
note JOCKEY!

Last edited by jtgh; 08-19-2013 at 05:00 AM..
  Reply With Quote
Old 05-02-2014, 12:55 AM   #194 (permalink)
Master EcoModder
Join Date: Oct 2008
Location: Dallas Fort Worth
Posts: 259

TexasThunder Avg MPG 54 - '08 Toyota Prius Base
Thanks: 223
Thanked 23 Times in 22 Posts
Originally Posted by bbjsw10 View Post
I installed an EOC switch today. Here is how I did it, should work on any 89-94 as far as I know.

Supplies needed:
1. momentary switch normally open
2. relay use a good one like Bosch 5 pole 30Amp
3. inline fuse holder capable of 20 amps
4. 15 amp fuse for holder
5. 16 gauge wire use no smaller than this or will over heat
6. ring terminal for grounding momentary switch
7. nylon ties
8. wire loom
9. (2) 1/4" male spade connectors for 16 gauge wire
10. (4) 1/4" female spade connectors used to connect wires to relay
11. Solder and soldering gun a must for underhood wires. Don't want to break down because of bad connections, Do you?

Begin by disconnecting battery. Pull 15 amp injector fuse in under hood fuse panel. Cut 2 sections of wire roughly 6 feet in length. Solder a spade connector onto fuse holder, and one section of above wire to other side of holder, mark this wire with a piece of tape at end. Solder another spade onto second wire used as return from relay. Run these 2 wires into underdash to mount relay. You will need the momentary switch grounded on one side, this will be to trigger relay. The other side of switch goes to relay. Diagram below. Mount your switch wherever it is easy to get to, I used my shifter knob. Once you have all connections made plug the fused wire into fuse panel and the unfused wire in as well. Pic below. Reconnect battery. Install fuse, match the size it calls for 15 Amp on my car. Start car, verify it runs. Press button verify it dies out.

To use while coasting shift to neutral for coast, hit button. Enjoy. Bump start vehicle, no key needed. Just release button, ease out in clutch in a higher gear, do not pop clutch, but do not overly slip either. Takes practice but saves alot of fuel. Questions just ask.

Edit: 85 and 86 are reversed on my diagram. These pins are the control side and reversible. One ground, One power. Makes no difference on the position of these 2.

this is kinda/sorta how I plan to do a toyota kill switch.
Does anyone know where you would get the mini fuse male spades to fit the fuse socket?
  Reply With Quote
Old 05-18-2014, 04:23 PM   #195 (permalink)
Not bad for a machine
dirtydave's Avatar
Join Date: Mar 2014
Location: Baltimore
Posts: 1,024

Maechunbu - Retired - '00 Kia Sephia 1.8I4 16VDOHC
Last 3: 45.28 mpg (US)

Slasher - '96 Chevy Corsica 2.2L 3speedauto
Duct Tape Aero Crew
Team Chevy
90 day: 34.76 mpg (US)
Thanks: 279
Thanked 241 Times in 178 Posts
Can someone make a shopping cart from a website I can buy everything from?
  Reply With Quote
Old 05-20-2014, 01:27 PM   #196 (permalink)
Moderate your Moderation.
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
I was considering doing this type of setup on my TDi.. but then I found out that it idles at .1gph, which really isn't enough for me to even bother worrying about.

This means on a full tank, I could let my car idle for 180 hrs. All friggin' week.

"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Reply  Post New Thread

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Kill switch for 88-95 Honda Civic/CRX/DelSol AndrewJ DIY / How-to 40 06-18-2012 03:13 AM
Kill switch accomplished homeworkhome53 DIY / How-to 22 08-11-2011 02:19 PM
Geo Metro Kill Switch Idea? HotRod EcoModding Central 5 01-27-2011 06:13 PM
help W/ Remote Kill Switch Idea 93hatchDX DIY / How-to 21 07-31-2008 03:46 PM
Winter mod - heater blower integrated with engine kill switch MetroMPG EcoModding Central 3 12-31-2007 10:31 PM

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2023, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com