Very well done video. Some reject fuel injection because they don't understand it. I get the fact that service/reliability is a reason, but IF they are designed right, FI is a just a better way and lasts forever. I remember when people rejected electronic ignition and disc brakes on cars saying points/condenser and drum brakes were better - really!!??
when it comes to lawn mowers the decision is tough and equally right on carb vs efi. either way you go in a lawn mower, will work great. Car or boat the answer is efi. I have a Kawasaki carb and Kohler carb engines that work great. 22hp Kohler carb engine in are Deere 130 has been around 6 year mowing 2.5 acres and never once gave a problem. And after a year of use the engine oil still looks clean.
Imo the best engine out this days as far as commerial wise is the Briggs and Stratton EFI Vanguard with the Oil Guard system. I have several different brands of mower/machines and that B&S oil guard is a fantastic idea they did for the commerial gear.
The oil guard simply allows longer change intervals. The oil filter is easier to change. But it doesn’t do anything for longevity compared to the standard change. Both engines have an oil cooler. Frankly if your machine sits unused during the off season the oil should be changed at the start of the season regardless due to condensation that will be in the oil. So in short, I’m not sold on the oil guard system but I do like the Vanguard EFI engines.
@@tylermacconnell217 one issue you didn't mention. If a wet sump system is low on oil (most fleet machines) and then you mow on a slope, the oil pump is sucking lots of air. Air makes a very poor lubricant. The MAJORITY of engine failures is not from normal wear but lack of lube. Also under high temps and heavy loads the dry sump tank significantly cools the engine oil more than that small heat exchanger next to the flywheel. One disadvantage of dry sump is cold weather, I warm the engines much more in cold weather before full load is applied almost 6 qts vs 2 qts of oil to heat up.
@@tylermacconnell217 there is less than 1 qt of oil in the engine at any time, 5 qts in the tank, the pump socks oil from the tank puts it under pressure and into the engine. The pump is not belt drive, that does not determine wet or dry sump. The location of the oil determines that.
@@firstname6208 I stand corrected. I looked at the Vanguard site and they are claiming it is a dry sump design. The added volume of oil, and being remote form the engine, will allow the engine to run a little cooler (even though they do both have an oil cooler, so apparently even the Oil Guard version still needs one).
On my new ( purchased on 28 August 2023 / now 15.6 hours ) ZXT 72 61G8 / sn: 161469LF : I just had my dealership: D & J Equipment, Inc in Longwood, FL, upgrade my mower to the Wright part #72410104 " Tweel Wheel Rear Tires." 🤠 OH YEA
I’m changing my two 37EFI Briggs to carbureted because the fuel injection sucks and it cost a lot of money to get the program to adjust it! I engine runs good the other will just shut down if you put low grade gas in it! After changing them over I want to see if I can run low grade gas. That would save me a lot of money!
I just want to know which one is more reliable. I really dont care if it's not efficient bc you're paying either way. Either you're paying for a fix and wasting time or paying a bit more and working more hours
The more electronic the more problems to trouble shoot & the more things that can go wrong when it rains; the more time trouble shooting = 0 work being done = 0 $💸 & more repair bills 💸💳 for being in the dealer’s repair shop, waiting on parts!!
Will the O2 sensor on the 37hp Briggs efi on wright zk if its bad will it make it run like one cylinder and hard to or not start up on cold in the morning
My ZK 52” has a Kohler efi 860. Currently in shop for 2nd time. First time @ 518 hrs severe engine knock. Dealer, Interstate Supplies & Service couldn’t find problem. Was told no engine runs perfectly. Now 693 hrs knock is worse. Told dealer to keep it until they find the problem. I do all maintenance at required times. Change filter with every oil change. Thoughts?
That knock you are hearing may be the hydraulic lifters being noisy. Some efi engine applications call for 20w50 oil which on a cold day will make the lifters tap hard. Also if the oil is starting to turn dark the lifter noise will be louder. Alot of people think it's a knock. Without seeing your machine I am simply just sending this suggestion out to you. I have had great results with putting a couple cap fulls of seafoam in the oil, it quiets down considerably after running full throttle for a few minutes. I hope this helps, Merry Christmas.
Are there any longevity benefits of an EFI engine vs. a carbureted engine in terms of mechanical wear from a more precise air/fuel ratio or do the carbureted engines, when working correctly, burn clean enough to keep fuel contamination manageable for the oil?
I have retrofit X2 Kohler 740 closed-loop EFI propane engines on some older mowers of mine. Is there a reason I don’t hardly see these on any other mowers, including Wright mowers? I’ve had nothing but good luck out of them and was wondering why they’re not popular with manufacturers. They’ve been reliable and efficient so far (both have at least 2000 hrs on them). Thanks, I’m just trying to figure out new mowers to purchase.
Very few companies, usually only municipalities with emissions requirements run propane. It’s never got traction in the US and most manufacturers have stopped offering propane. Kohler engines are good up to about 26hp in the Command series. Once you step up to the big block Kohler’s 29+ up they have major issues. Hence why almost all OEMs have dropped Kohler big block offerings. They’re basically a 500hr grenade.
Propane runs very clean, and your oil stays cleaner. It may produce a little less power compared to a gas equivalent. The main reason propane hasn’t taken off is needing two huge tanks to mount externally and no being easy to refill versus gas out of a 5 gallon can if you run out.
The guys that dont trust efi must drive a truck that is at least 35 years old. My 07 and 09 fords ran 250k miles with almost no repairs. My carbureted vehicles always needed this or that. My 86 chevy k20 pickup is like a 2500hd of today. It has a 5.7L v8 that gets 12 to16 mpg and has 160hp and 260lbs torque. A 1987 5.7L v8 had PRIMITAVE fuel injection system and made 205hp and 310lbs of torque.... modern day F150 with a 2.7L turbo v6 makes double the power and has a flat torque curve thats 100lbs higher than my 5.7L and gets 25mpg unloaded.... ppl buy an efi of current technology, theres no reason to use a gas guzzling carburetor. If you arent running EFI you better be like me and running a diesel mower with mechanical injection system
What motor do you run on your mowers? Lmk when they hit 1500 hrs if they ever make it there. Not trying to be mean but I’m out here to cut grass and make money not have my efi mower stuck at the shop getting fixed every few hundred hrs.
@@jonnyg44 I was running a Kubota diesel mower back then for main mower and have 2 carburetor type kawi powered walk behind. A number of ppl I've talked to over the years get 2-3k hours out of mowers with Kohler EFI
I had my cub cadet riding efi riding mower in the shop 4 times last year. Still dying out...now being told the efi's are "nothing but problems...they clog easily...backfiring..but shouldn't. " Modulator and governor spring already replaced. Only 3 1/2 years old. 46inch deck. Very disappointed and still no solutions...limited repair services for efi too.
Quick question for you it’s a little bit off topic but whenever I step on my 2020 stander x it makes a noise in the gas tank I figured it is the magnet rattling back-and-forth with the gas is there anyway to prevent this or fix it?
You're most likely hearing the cut-off switch designed to shut off the blades if the operator steps off the machine while blades are running. ua-cam.com/video/Vbl50E-tPzc/v-deo.html
I saw your new zxt please put some type of latches on the hose for bagger we take them on and off all the time due to clogging and over filling the bagger all the time plus taking it off for the lawns we dont bag,have clamps on my ferris bagger pain in the butt compared to my exmark
Thoughts on mowers that use an non tubular frame? c channel frame or an I beam front end? Seems to be ways of using less steel and keeping price low at the cost of some durability.
you all probably dont care but does anybody know a tool to get back into an instagram account?? I was dumb forgot my login password. I love any tips you can give me!
@Emerson Garrett I really appreciate your reply. I found the site thru google and Im trying it out atm. Seems to take quite some time so I will reply here later when my account password hopefully is recovered.
I would disagree with one point, the closed loop EFI engines(Kohler & Vanguard) get noticeably better fuel economy than open loop(Kawasaki) in my observations. Now the difference in fuel economy could be due to other factors, but I think it’s far more than a coincidence. Just my opinion, but I think Vanguard is the best EFI engine, for that matter, I think Vanguard are the best mower engines period.
@@851995STARGATE how much do you think a fuel pump for a mower cost, or an O2 sensor? I’m sure vanguard and kawi have decent efi motors but they are more complicated and yes they do cost more for a replacement.
i wonder why manufactures dont use the smaller 19hp efi engines on the smaller mowers if the benefit is that much fuel savings? they should have that option at least...and liquid cooling on 18-40hp engines with efi...its supposed to be better so why not make it?
Actually it was called Lambdasond (Lambda being the Greek symbol for oxygen/air I believe). And while it Was on my Volvo, it may have been invented by Bosch for Volvo as part of their K-Jetronic system~
You've done a poor job of explaining the differences in closed-loop versus open-loop EFI. There is a significant fuel savings in a closed-loop versus open-loop fuel injected mower engine. You made mention of higher operating temperatures negating the efficiency of closed-loop fuel injecting, when in reality you must reach full operating engine temperature for the oxygen sensor to perform as designed. I think people should have accurate information based on actual technology, not opinion. QUOTE: The Electronic Fuel Injection (EFI) system is a complete engine fuel and ignition management design. The system includes the following principal components: • Fuel Pump • Fuel Filter • Fuel Rail • Fuel Line(s) • Fuel Pressure Regulator • Fuel Injectors • Throttle Body/Intake Manifold • Engine Control Unit (ECU) • Ignition Coils • Engine (Oil) Temperature Sensor • Throttle Position Sensor (TPS) • Speed Sensor • Oxygen Sensor • Wire Harness Assembly & Affiliated Wiring, • Malfunction Indicator Light (MIL) Operation The EFI system is designed to provide peak engine performance with optimum fuel efficiency and lowest possible emissions. The ignition and injection functions are electronically controlled, monitored and continually corrected during operation to maintain the theoretical ideal or “stoichiometric” air/fuel ratio of 14.7:1. The central component of the system is the Motronic™ Engine Control Unit (ECU) which manages system operation, determining the best combination of fuel mixture and ignition timing for the current operating conditions. An electric fuel pump is used to move fuel from the tank through the fuel line and in-line fuel filter. A fuel pressure regulator maintains a system operating pressure of 39 psi and returns any excess fuel to the tank. At the engine, fuel is fed through the fuel rail and into the injectors, which inject it into the intake ports. The ECU controls the amount of fuel by varying the length of time that the injectors are “on.” This can range from 1.5-8.0 milliseconds depending on fuel requirements. The controlled injection of the fuel occurs each crankshaft revolution, or twice for each 4- stroke cycle. One-half the total amount of fuel needed for one firing of a cylinder is injected during each injection. When the intake valve opens, the fuel/air mixture is drawn into the combustion chamber, ignited, and burned. The ECU controls the amount of fuel being injected and the ignition timing by monitoring the primary sensor signals for engine temperature, speed (RPM), and throttle position (load). These primary signals are compared to preprogrammed “maps” in the ECU computer chip, and the ECU adjusts the fuel delivery to match the mapped values. After the engine reached operating temperature, an exhaust gas oxygen sensor provides feedback to the ECU based upon the amount of unused oxygen in the exhaust, indicating whether the fuel mixture being delivered is rich or lean. Based upon this feedback, the ECU further adjusts fuel input to re-establish the ideal air/fuel ratio. This operating mode is referred to as “closed loop” operation. The EFI system operates “closed loop” when all three of the following conditions are met: a. The oil temperature is greater than 35°C (86°F). b. The oxygen sensor has warmed sufficiently to provide a signal (minimum 375°C, 709°F). c. Engine operation is at a steady state (not starting, warming up, accelerating, etc.). During “closed loop” operation the ECU has the ability to readjust temporary and learned adaptive controls, providing compensation for changes in overall engine condition and operating environment, so it will be able to maintain the ideal air/fuel ratio of 14.7:1. The system requires a minimum engine oil temperature greater than 55°C (130°F) to properly adapt. These adaptive values are maintained as long as the ECU is “powered up” by the battery. During certain operating periods such as cold starts, warm up, acceleration, etc., an air/fuel ratio richer than 14.7:1 is required and the system operates in an “open loop” mode. In “open loop” operation the oxygen sensor output is not used, and the controlling adjustments are based on the primary sensor signals and programmed maps only.
Agreed, he was definitely off on the closed loop vs open loop. No doubt, much better fuel economy with closed loop. All modern vehicles run closed loop.
Im old school, give me a carb on an engine! just my opinion have a blessed day folks
wondering why someone thumbs down on this one. seems like a lot of good info.
Very well done video. Some reject fuel injection because they don't understand it. I get the fact that service/reliability is a reason, but IF they are designed right, FI is a just a better way and lasts forever. I remember when people rejected electronic ignition and disc brakes on cars saying points/condenser and drum brakes were better - really!!??
Very informative and helpful. Thanks Ed.
Your videos are smooth. You have mowing looking cool. Fonzy cool.
He EFI lawn mower motors that the company i work for has had in the past do not last as many hours as carbureted motors do.
Problem around here is lack of skill at local mower shop's ability to repair EFI engines...
when it comes to lawn mowers the decision is tough and equally right on carb vs efi. either way you go in a lawn mower, will work great. Car or boat the answer is efi. I have a Kawasaki carb and Kohler carb engines that work great. 22hp Kohler carb engine in are Deere 130 has been around 6 year mowing 2.5 acres and never once gave a problem. And after a year of use the engine oil still looks clean.
Imo the best engine out this days as far as commerial wise is the Briggs and Stratton EFI Vanguard with the Oil Guard system. I have several different brands of mower/machines and that B&S oil guard is a fantastic idea they did for the commerial gear.
The oil guard simply allows longer change intervals. The oil filter is easier to change. But it doesn’t do anything for longevity compared to the standard change. Both engines have an oil cooler. Frankly if your machine sits unused during the off season the oil should be changed at the start of the season regardless due to condensation that will be in the oil. So in short, I’m not sold on the oil guard system but I do like the Vanguard EFI engines.
@@tylermacconnell217 one issue you didn't mention. If a wet sump system is low on oil (most fleet machines) and then you mow on a slope, the oil pump is sucking lots of air. Air makes a very poor lubricant. The MAJORITY of engine failures is not from normal wear but lack of lube. Also under high temps and heavy loads the dry sump tank significantly cools the engine oil more than that small heat exchanger next to the flywheel. One disadvantage of dry sump is cold weather, I warm the engines much more in cold weather before full load is applied almost 6 qts vs 2 qts of oil to heat up.
@@firstname6208 Vanguard engines with Oil Guard are NOT dry sump engines. They would not behave any differently on a slope.
@@tylermacconnell217 there is less than 1 qt of oil in the engine at any time, 5 qts in the tank, the pump socks oil from the tank puts it under pressure and into the engine. The pump is not belt drive, that does not determine wet or dry sump. The location of the oil determines that.
@@firstname6208 I stand corrected. I looked at the Vanguard site and they are claiming it is a dry sump design. The added volume of oil, and being remote form the engine, will allow the engine to run a little cooler (even though they do both have an oil cooler, so apparently even the Oil Guard version still needs one).
On my new ( purchased on 28 August 2023 / now 15.6 hours ) ZXT 72 61G8 / sn: 161469LF : I just had my dealership: D & J Equipment, Inc in Longwood, FL, upgrade my mower to the Wright part #72410104 " Tweel Wheel Rear Tires." 🤠 OH YEA
I’m changing my two 37EFI Briggs to carbureted because the fuel injection sucks and it cost a lot of money to get the program to adjust it!
I engine runs good the other will just shut down if you put low grade gas in it! After changing them over I want to see if I can run low grade gas. That would save me a lot of money!
Great video Ed
Thanks 👍
I just want to know which one is more reliable. I really dont care if it's not efficient bc you're paying either way. Either you're paying for a fix and wasting time or paying a bit more and working more hours
The more electronic the more problems to trouble shoot & the more things that can go wrong when it rains; the more time trouble shooting = 0 work being done = 0 $💸 & more repair bills 💸💳 for being in the dealer’s repair shop, waiting on parts!!
Will the O2 sensor on the 37hp Briggs efi on wright zk if its bad will it make it run like one cylinder and hard to or not start up on cold in the morning
Great video. Thoughts on the fx1000 efi?
Good engine. Because it has a one-piece block, I'd like to see 8 bolt holes to hold it on the mower. -Ed
@@WrightMowers Will that engine be available on zk for spring 2021
My ZK 52” has a Kohler efi 860. Currently in shop for 2nd time. First time @ 518 hrs severe engine knock. Dealer, Interstate Supplies & Service couldn’t find problem. Was told no engine runs perfectly. Now 693 hrs knock is worse. Told dealer to keep it until they find the problem. I do all maintenance at required times. Change filter with every oil change. Thoughts?
That knock you are hearing may be the hydraulic lifters being noisy. Some efi engine applications call for 20w50 oil which on a cold day will make the lifters tap hard. Also if the oil is starting to turn dark the lifter noise will be louder. Alot of people think it's a knock. Without seeing your machine I am simply just sending this suggestion out to you. I have had great results with putting a couple cap fulls of seafoam in the oil, it quiets down considerably after running full throttle for a few minutes. I hope this helps, Merry Christmas.
My was the valve seal i replace with whole cilinder head new
Can you switch from an Briggs efi 37hp to a carb Kawasaki fx850 on the wright stander ZK
Are there any longevity benefits of an EFI engine vs. a carbureted engine in terms of mechanical wear from a more precise air/fuel ratio or do the carbureted engines, when working correctly, burn clean enough to keep fuel contamination manageable for the oil?
Thanks for the info it's very helpful. Your videos are always so informative.
Very informative!
Thanks for watching!
I have retrofit X2 Kohler 740 closed-loop EFI propane engines on some older mowers of mine. Is there a reason I don’t hardly see these on any other mowers, including Wright mowers? I’ve had nothing but good luck out of them and was wondering why they’re not popular with manufacturers. They’ve been reliable and efficient so far (both have at least 2000 hrs on them). Thanks, I’m just trying to figure out new mowers to purchase.
Very few companies, usually only municipalities with emissions requirements run propane. It’s never got traction in the US and most manufacturers have stopped offering propane. Kohler engines are good up to about 26hp in the Command series. Once you step up to the big block Kohler’s 29+ up they have major issues. Hence why almost all OEMs have dropped Kohler big block offerings. They’re basically a 500hr grenade.
I beleive the Kohler cv980 38hp in The toro 38 stump grinders were
all replaced under warranty
Propane runs very clean, and your oil stays cleaner. It may produce a little less power compared to a gas equivalent. The main reason propane hasn’t taken off is needing two huge tanks to mount externally and no being easy to refill versus gas out of a 5 gallon can if you run out.
The guys that dont trust efi must drive a truck that is at least 35 years old. My 07 and 09 fords ran 250k miles with almost no repairs. My carbureted vehicles always needed this or that. My 86 chevy k20 pickup is like a 2500hd of today. It has a 5.7L v8 that gets 12 to16 mpg and has 160hp and 260lbs torque. A 1987 5.7L v8 had PRIMITAVE fuel injection system and made 205hp and 310lbs of torque.... modern day F150 with a 2.7L turbo v6 makes double the power and has a flat torque curve thats 100lbs higher than my 5.7L and gets 25mpg unloaded.... ppl buy an efi of current technology, theres no reason to use a gas guzzling carburetor. If you arent running EFI you better be like me and running a diesel mower with mechanical injection system
What motor do you run on your mowers? Lmk when they hit 1500 hrs if they ever make it there. Not trying to be mean but I’m out here to cut grass and make money not have my efi mower stuck at the shop getting fixed every few hundred hrs.
@@jonnyg44 is it that bad with these efi engines?
@@jonnyg44 I was running a Kubota diesel mower back then for main mower and have 2 carburetor type kawi powered walk behind.
A number of ppl I've talked to over the years get 2-3k hours out of mowers with Kohler EFI
@@jaybrown29no less reliable than EFI on an ATV or pickup truck. Nice not needing to buy non ethanol gas for EFI motors
I had my cub cadet riding efi riding mower in the shop 4 times last year. Still dying out...now being told the efi's are "nothing but problems...they clog easily...backfiring..but shouldn't. " Modulator and governor spring already replaced. Only 3 1/2 years old. 46inch deck. Very disappointed and still no solutions...limited repair services for efi too.
Quick question for you it’s a little bit off topic but whenever I step on my 2020 stander x it makes a noise in the gas tank I figured it is the magnet rattling back-and-forth with the gas is there anyway to prevent this or fix it?
You're most likely hearing the cut-off switch designed to shut off the blades if the operator steps off the machine while blades are running. ua-cam.com/video/Vbl50E-tPzc/v-deo.html
It’s a ticking noise. It’s the gas gauge moving with the gas moving.
I saw your new zxt please put some type of latches on the hose for bagger we take them on and off all the time due to clogging and over filling the bagger all the time plus taking it off for the lawns we dont bag,have clamps on my ferris bagger pain in the butt compared to my exmark
Thoughts on mowers that use an non tubular frame? c channel frame or an I beam front end? Seems to be ways of using less steel and keeping price low at the cost of some durability.
you all probably dont care but does anybody know a tool to get back into an instagram account??
I was dumb forgot my login password. I love any tips you can give me!
@Kyrie Castiel instablaster ;)
@Emerson Garrett I really appreciate your reply. I found the site thru google and Im trying it out atm.
Seems to take quite some time so I will reply here later when my account password hopefully is recovered.
@Emerson Garrett it did the trick and I actually got access to my account again. Im so happy:D
Thank you so much you saved my ass !
@Kyrie Castiel happy to help xD
This is so good
I run both and prefer the carb..better fuel consumption (being honest), especially with a kawi. They last longer too.
Do you know what RPM vanguard 37 hp EFI should be with no load?
Approx 3,600RPM
I would disagree with one point, the closed loop EFI engines(Kohler & Vanguard) get noticeably better fuel economy than open loop(Kawasaki) in my observations. Now the difference in fuel economy could be due to other factors, but I think it’s far more than a coincidence. Just my opinion, but I think Vanguard is the best EFI engine, for that matter, I think Vanguard are the best mower engines period.
One thing I do know is Efi engines sure start better in cold weather.
Best coments
, Thanks
Does efi tend to start a little easier?
Yeah but when they break it tends to cost a lot more to fix. More sensors=more stuff to break
@@jonnyg44 that's a really old stupid concept
@@851995STARGATE how much do you think a fuel pump for a mower cost, or an O2 sensor? I’m sure vanguard and kawi have decent efi motors but they are more complicated and yes they do cost more for a replacement.
i wonder why manufactures dont use the smaller 19hp efi engines on the smaller mowers if the benefit is that much fuel savings? they should have that option at least...and liquid cooling on 18-40hp engines with efi...its supposed to be better so why not make it?
You seem to know your shit, good job explaining.
Volvo invented that in 1977 called lambasom the oxygen sensor in the tail pipe and a computer monitor the fuel ratio 😀 yes I was a volvo dealer then🙂
Actually it was called Lambdasond (Lambda being the Greek symbol for oxygen/air I believe). And while it Was on my Volvo, it may have been invented by Bosch for Volvo as part of their K-Jetronic system~
You've done a poor job of explaining the differences in closed-loop versus open-loop EFI. There is a significant fuel savings in a closed-loop versus open-loop fuel injected mower engine. You made mention of higher operating temperatures negating the efficiency of closed-loop fuel injecting, when in reality you must reach full operating engine temperature for the oxygen sensor to perform as designed. I think people should have accurate information based on actual technology, not opinion.
QUOTE:
The Electronic Fuel Injection (EFI) system is a
complete engine fuel and ignition management
design. The system includes the following principal
components:
• Fuel Pump
• Fuel Filter
• Fuel Rail
• Fuel Line(s)
• Fuel Pressure Regulator
• Fuel Injectors
• Throttle Body/Intake Manifold
• Engine Control Unit (ECU)
• Ignition Coils
• Engine (Oil) Temperature Sensor
• Throttle Position Sensor (TPS)
• Speed Sensor
• Oxygen Sensor
• Wire Harness Assembly & Affiliated Wiring,
• Malfunction Indicator Light (MIL)
Operation
The EFI system is designed to provide peak engine
performance with optimum fuel efficiency and lowest
possible emissions. The ignition and injection
functions are electronically controlled, monitored and
continually corrected during operation to maintain the
theoretical ideal or “stoichiometric” air/fuel ratio of
14.7:1.
The central component of the system is the Motronic™
Engine Control Unit (ECU) which manages system
operation, determining the best combination of fuel
mixture and ignition timing for the current operating
conditions.
An electric fuel pump is used to move fuel from the
tank through the fuel line and in-line fuel filter. A fuel
pressure regulator maintains a system operating
pressure of 39 psi and returns any excess fuel to the
tank. At the engine, fuel is fed through the fuel rail
and into the injectors, which inject it into the intake
ports. The ECU controls the amount of fuel by varying
the length of time that the injectors are “on.” This can
range from 1.5-8.0 milliseconds depending on fuel
requirements. The controlled injection of the fuel
occurs each crankshaft revolution, or twice for each 4-
stroke cycle. One-half the total amount of fuel needed
for one firing of a cylinder is injected during each
injection. When the intake valve opens, the fuel/air
mixture is drawn into the combustion chamber,
ignited, and burned.
The ECU controls the amount of fuel being injected
and the ignition timing by monitoring the primary
sensor signals for engine temperature, speed (RPM),
and throttle position (load). These primary signals are
compared to preprogrammed “maps” in the ECU
computer chip, and the ECU adjusts the fuel delivery
to match the mapped values. After the engine reached
operating temperature, an exhaust gas oxygen sensor
provides feedback to the ECU based upon the amount
of unused oxygen in the exhaust, indicating whether
the fuel mixture being delivered is rich or lean. Based
upon this feedback, the ECU further adjusts fuel input
to re-establish the ideal air/fuel ratio. This operating
mode is referred to as “closed loop” operation. The
EFI system operates “closed loop” when all three of
the following conditions are met:
a. The oil temperature is greater than 35°C (86°F).
b. The oxygen sensor has warmed sufficiently to
provide a signal (minimum 375°C, 709°F).
c. Engine operation is at a steady state (not starting,
warming up, accelerating, etc.).
During “closed loop” operation the ECU has the
ability to readjust temporary and learned adaptive
controls, providing compensation for changes in
overall engine condition and operating environment,
so it will be able to maintain the ideal air/fuel ratio of
14.7:1. The system requires a minimum engine oil
temperature greater than 55°C (130°F) to properly
adapt. These adaptive values are maintained as long
as the ECU is “powered up” by the battery.
During certain operating periods such as cold starts,
warm up, acceleration, etc., an air/fuel ratio richer
than 14.7:1 is required and the system operates in an
“open loop” mode. In “open loop” operation the
oxygen sensor output is not used, and the controlling
adjustments are based on the primary sensor signals
and programmed maps only.
Agreed, he was definitely off on the closed loop vs open loop. No doubt, much better fuel economy with closed loop. All modern vehicles run closed loop.