Re: Yamaha OX 66 200 HP Questions
wow<br /> but it will go up here soon. its gonna cost me almost 700 dollars just for another week of school and gas last year was about 1.20 and now its 2.40 a gallon.<br /> so I can only absorb so much and every other tech and dealer is in the same boat.<br />\ but everything is going up, LPG, gas,diesel. parts due to the price of plastics and electricity.<br /> in fact we were disscussing today as to raise from 75hr to 90 this year or go to 100hr in 07. I voted for 90 and if we get out of Iraq and gas goes back to 1 dollar a gallon as per Rumsfeld's TV promise, we dont have to lower the price so much.<br /> most the dealers around here try to opererate on a 30% margin.<br /> but the cost seems reasonable to me. <br /> the TPS explanation does not make sense, the engine gets its RPM info from the pulsers and the TPS gives throttle angle.<br /> a simple explanation is at .5V the ecu sees the shutters as fully closed, the CPS detects crankshaft phase angle(which piston is where) and the rulser coils provide information on RPM and assist in ign timing control.<br /> we know there is 35PSI of fuel waiting at the injector, we know that X amount of injector "on" time will deliver X amount of fuel.<br /> ok we are idling at 730 RPM. the TPS is about .62V we want to accelerate.<br /> now the TPS angle suddenly changes and goes to say 3.5V, the ECU is looking at that and at the RPM from the pulsers and the CPS.<br /> it knows that the values are not correct.<br /> it now adds fuel by increaseing the injector "on" time and adding a specified amount of ign timing advance.<br /> its looking for the Map values to null themselves.<br /> the ECU map sees the engine load through the TPS, the barometric pressure the intake air temp(for air density) and RPM. it will adjust fuel delivery and ign timing in an attempt to make the ECU map correct.<br /> the knock sensor gives info on detonation and if detected can add fuel and retard ign timing. the O2 sensor is giving the amount of O2 (unburned hydrocarbon comparison) information so the ECU is constantly making minor corrections to fuel mix in an attempt to hold a 14/1 air fuel ratio.<br /> thats a basic electronic EFI. most all speed density systems work that way. some systems dont use an O2 sensor. but all have to have a means of detecting throttle angle,crank phase angle and crank speed.<br /> aint but so many ways to do it.<br /> failure of the actual EFI stuff is rare. mostly its adjustments and mechanical failures such as a bad fuel pump diaphram. stupid computer cant detect that. stupid puter also cannot detect low fuel rail pressure due to a clogged VST filter.<br /> stupid puter cannot detect a dirty O2 sensor either and can lean out the air/fuel mix above 4000 RPM and smoke a piston.<br />and there is the twofold issue of running an OX 66 motor with a bad low pressure pump. not only is it leaking raw fuel with no oil into the crankcase causing a flooding condition the O2 sensor will pick it up as an over rich condition and lean out the incoming air/fuel to all six cylinders thus reducing the availible lubricaton even more.<br /> poof no piston and occasionally bang the rod cap is now hanging outside the crankcase.<br /> its all about the proper maint with a tech that cares.<br />and no the fuel pump is mention nowhere as a maint item, that comes from a few days experience.