Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Getting the most out of lean burn (Honda)

greasemonkee · 10-01-2012, 01:44 AM

This is the best I can break it down:

Here's the pulse generator - New NE555 Square wave signal generator 1hz-500khz | eBay

It's not perfect, but does the job. This makes the ecu think the car is rolling at 60 mph, to the speed lower the board would need to be modified, doubtful it would make a difference anyway. The jumper must go in the 50 Hz to 1Khz slot and the frequency turned down to the lower end of the adjustment - frequency and duty cycle should really should be matched up to the waveform of the stock VSS with a scope, but you might get lucky and hit the sweet spot.

*Signal line - Intercept the VSS signal to the ecu, that is pin B10 (yel/blu). Cut that line, cap the side going back into the harness and feed the output signal of the pulse generator into the ecu.

*12V+ can be found at A25 or B1 (yel/blk)

* Ground can be found at A23 or A24 (blk)

Solder the lines to the pulse generator, grab a small project box from radio shack, and stuff some foam around the board to secure it.

Now you've got leanburn in any gear, when stationary with the throttle slightly depressed, and at lower coolant temps.

NOTE: fast idle is always active and might kick up the idle a hair, add a toggle switch in the VSS line if necessary.

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Removing MAP signal may be as easy as using a resistor in the map signal line, but the better way would be to grab an Apexi SAFC, VAFC, VAFC2, or NEO. The older non-vtec version should work fine, they often go for $100-$150 on craigslist or ebay. This way you have more control over rpm and throttle position over how much fuel you're pulling.

Be aware that the more fuel you pull, the more timing you add, also the timing curves get more out of whack so use with caution and listen for detonation. My settings wound up at -8% fuel and 12* distributor timing. The oxygen sensor will add fuel as needed to compensate so increasing the fuel pressure is not necessary.

10-01-2012, 01:44 AM	#26 (permalink)
greasemonkee EcoModding Apprentice Join Date: May 2009 Location: Western NC Posts: 177 Thanks: 3 Thanked 43 Times in 19 Posts	This is the best I can break it down: Here's the pulse generator - New NE555 Square wave signal generator 1hz-500khz \| eBay It's not perfect, but does the job. This makes the ecu think the car is rolling at 60 mph, to the speed lower the board would need to be modified, doubtful it would make a difference anyway. The jumper must go in the 50 Hz to 1Khz slot and the frequency turned down to the lower end of the adjustment - frequency and duty cycle should really should be matched up to the waveform of the stock VSS with a scope, but you might get lucky and hit the sweet spot. Signal line - Intercept the VSS signal to the ecu, that is pin B10 (yel/blu). Cut that line, cap the side going back into the harness and feed the output signal of the pulse generator into the ecu. 12V+ can be found at A25 or B1 (yel/blk) * Ground can be found at A23 or A24 (blk) Solder the lines to the pulse generator, grab a small project box from radio shack, and stuff some foam around the board to secure it. Now you've got leanburn in any gear, when stationary with the throttle slightly depressed, and at lower coolant temps. NOTE: fast idle is always active and might kick up the idle a hair, add a toggle switch in the VSS line if necessary. ---------------------------------------------- Removing MAP signal may be as easy as using a resistor in the map signal line, but the better way would be to grab an Apexi SAFC, VAFC, VAFC2, or NEO. The older non-vtec version should work fine, they often go for $100-$150 on craigslist or ebay. This way you have more control over rpm and throttle position over how much fuel you're pulling. Be aware that the more fuel you pull, the more timing you add, also the timing curves get more out of whack so use with caution and listen for detonation. My settings wound up at -8% fuel and 12* distributor timing. The oxygen sensor will add fuel as needed to compensate so increasing the fuel pressure is not necessary. Last edited by greasemonkee; 10-01-2012 at 02:07 AM..