O2 Sensor in Yamaha FT60DET 2008

[rodbolt17]

the only function of the regulator is to maintain rail pressure at a specified pressure.
the ECU does NOT monitor rail pressure it assumes its correct.

at rapid throttle opening the vacuum sense line has a lowered vacuum(higher pressure) and adds about 5PSI on the rail.

this allows for the sequential AND group injection nessasary to accelerate smoothly with no backfire in the intake.

remember manifold pressure is an inverse to manifold vacuum.

at or near WOT intake vacuum will be close to 0"Hg.
manifold pressure will be about barometric pressure.

what is the MAP sensor showing at key on engine off?

sometimes the motor can suffer altitude sickness.

I can tell you for a fact the 2007 F250 can operate at 22,000 ft.

when the map sensor failed the ECU read the input as 22,000 ft and adjusted the fuel curve accordingly.
it ran like crap at se*****l.

the EFI F60 runs very well when all is good and all the thingy's are happy.

you simply have to figure out which thingy aint happy and fix it.
ALL the engineering work has been done.

I usually start with a basic leakdown test to make sure the cylinders can actually seal.
then I move on to a simple spark test to see if the spark PRODUCING components can do the job.
then its on to test the fuel system.

you should see an EFI 5.7L Volvo run when the rail pressure is above 100 PSI.
spec is about 55 PSI.

[boscoe99]

We need to put a stake through the heart of the word "vacuum" and never ever use it again.

Would that it had never been coined.

Pressure is pressure. Or, there is none. To ever have called a reduction in pressure a "vacuum" was silly at best and stupid at worst.

[rodbolt17]

goes back to the days of carbed motors, however not all EFI ECU's use the same pressure protocols.
can get confusing.

back in the day a good running 350 carbed chebby would idle at about 20"Hg.
assuming its a nice day baro pressure would be about 31" .

by doing a bit of math the map pressure would be about 11".
31"-20"
its actually a decent troubleshooting aide.
look at map pressure at key on engine off then compare it at idle.


it actually works out fairly close.

ya gotta remember some of us are gray haired and remember carbs,drum brakes at all 4 corners, setting dwell on points, generators and mechanical voltage regulators.

[boscoe99]

I am older than you Rodbolt and certainly remember all of those things of which you spoke.

When using manifold pressure there is no need to do math. It is simply pressure. Whatever that pressure happens to be at the time. If a certain pressure was expected at idle RPM and the pressure was higher than normal that was a clue that something was wrong. If a certain pressure was expected at high RPM and the pressure is lower than normal that was a clue that something was wrong.

Take blood pressure. Let's say 100/80 is normal. If it is below 100/80 they don't translate it into a vacuum reading. It is simply a lower pressure than normal. It might simply be stated as 90/75 not some reading that translates into something referred to as minus 10/minus 5.

I have hated the term vacuum ever since my first basic physics course.

Oh well, it is what it is.

[rodbolt17]

back in the day, motors had no pressure nor vacuum sensors.

mechanics only had a simple vacuum gauge to test for leaks,broken valve springs ect ect.

its a holdover from another time.

kinda like vacuum operated windshield wipers.

hit the gas hard and they quit for a bit.

but yes I would love to see ALL manufactures use a standard language and protocalls.

with modern electronics there is no need for "Hg.
PSI works fine.

at the end of the day its still all about that 14 mile high colum of air we live in.

I have been doing this since I was about 8, doing it professionally since about age 15, Ill be 53 in nov.
got my first chiltons manual at age 8, still have it.
covers briggs and Stratton,Kohler,Onan, wisconsin and Techumpse.
had a mini bike my dad helped get running.
bought it with a hole in the block.
the next weekend he gave me the manual and said if you wish to ride, fix it yourself.

[99yam40]

ya gotta remember some of us are gray haired and remember carbs,drum brakes at all 4 corners, setting dwell on points, generators and mechanical voltage regulators.

those were the days you could play with the vehicles and make them work no matter what.
now a days not much can be done to make it limp back home.
I had a generator on a 64 Galexie 500 XL lock up on me heading home from school. rigged up an idler pulley to get water pump to turn and drove over 200 miles home. Battery kept things running well but needed a charge when I got there.
Life was so much simpler back 40 to 50 years ago

I had a 65 t bird with hydrolic windshield wipers , ran off power steering pump.
it had 8 speeds and would almost chunk the blades off at high speed.
Never seen anything like that since

The 65 T bird and 65 Mustang 2+2 I owned were the 1st disc brakes I had on cars, but the Bird was power assisted and the stang was not.
The 4 piston calipers were a pain. One piston was always going to stick and cause uneven wear.
I guess buying used vehicles even now can be a pain sometimes

[Christian]

Burning Rich

*** was busy with work and missed some of the feedback.

I did a test yesterday with a fuel pressure gauge plumped in with a T just before the fuel rail. No matter the load or rpm it never dropped before 40psi.


Then I blocked off the pipe from the fuel pressure regulator. Hooked a length of pipe directly to the regulator and the other end to an empty R22 freon bottle that I had evacuated to 30 inches (gauge) (thats what I mean by negative pressure sometimes referred to "a vacuum". When I opened the the gauges manifold and created an "artificial" vacuum the fuel pressure dropped to 30psi and the horrible smelly exhaust terminated. Did a go slow run with the wife @ 900 to 1000 rpm (4 kn/hr) at 224ml / kM. Best ever! That translates to 4.46 KM per liter or 10.46 miles (statue) per US gallon. Could be better I think. Notwithstanding other variables tide wind etc.

Defective regulator?


Anyone tried a PWM (DC motor speed con*****er) on the fuel pump as a way of leaning the mixture?


Thank you for all you help!!


Will look for that O2 port

[Christian]

Boscoe,

Did you mean #26 re the plug?

Cheers,
Christian

[rodbolt17]

instead of jinky rigging thingies???
why not simply fix the motor?
that engine runs very well when all the thingy's are happy happy.

your going to keep messing about until you post about a failed piston/cylinder due to fuel wash or a failed ex valve cause it ran lean.

fuel wash occurs when the A/F mix is so rich it leaves unburned fuel that tends to wash the oil off the cyl and piston skirt while diluting the engine oil with gas.

a burned ex valve is typically the result of excessive combustion temps due to a lean A/F mix.

40 psi is about the correct rail pressure.
means you don't have to twack that wabbit.

[boscoe99]

Boscoe,

Did you mean #26 re the plug?

Cheers,
Christian

Sorry. Yes, it is item 26.

[boscoe99]

*** was busy with work and missed some of the feedback.

I did a test yesterday with a fuel pressure gauge plumped in with a T just before the fuel rail. No matter the load or rpm it never dropped before 40psi.


Then I blocked off the pipe from the fuel pressure regulator. Hooked a length of pipe directly to the regulator and the other end to an empty R22 freon bottle that I had evacuated to 30 inches (gauge) (thats what I mean by negative pressure sometimes referred to "a vacuum". When I opened the the gauges manifold and created an "artificial" vacuum the fuel pressure dropped to 30psi and the horrible smelly exhaust terminated. Did a go slow run with the wife @ 900 to 1000 rpm (4 kn/hr) at 224ml / kM. Best ever! That translates to 4.46 KM per liter or 10.46 miles (statue) per US gallon. Could be better I think. Notwithstanding other variables tide wind etc.

Defective regulator?


Anyone tried a PWM (DC motor speed con*****er) on the fuel pump as a way of leaning the mixture?


Thank you for all you help!!

Will look for that O2 port

Why not just follow the service manual check procedure?

Install a fuel pressure gauge on the Schrader valve. Turn the key on and measure the pressure. Spec is 41.2 psi. Start the motor, let it warm up for five minutes and measure the pressure. Spec is 32.7 psi.

Then remove the sense line to the fuel pressure regulator. Connect a vacuum pump to the sense line. Apply a vacuum to the fuel pressure regulator using the vacuum pump. As the vacuum is increased the fuel pressure should decrease. If the fuel pressure does not decrease as a vacuum is applied then the regulator is defective and should be replaced.

Go here and read up on pressure regulators and EFI systems.
http://www.enginebasics.com/Engine%2...Regulator.html

[rodbolt17]

and Boscoe will still not say I am right.

[boscoe99]

and Boscoe will still not say I am right.

About what? Refresh my poor and tired memory.

[Christian]

Yes indeed I know the risks of messing or trying to improve the fuel economy that is one reason I need (will install) the air fuel mix meter in number 26 plug of the exhaust cover and get some meaningful readings.

I refuse to accept bad (too rich) mixture. There seems to be some evidence (above) that Yamaha have a tendency to set the mixture somewhat rich. Even when the engine is cold she doesn't like 41psi fuel pressure. (when I lower it to 32psi the rpm picks up) assume this is because the "brain" is reading a cold engine temp sensor and is increasing the time (milliseconds) that the injector is open per rev.


I am going to try a PWM (Pulse width modulator) to lower the rpm of the fuel pump. The ECM does not read fuel pump pressure on this model. Of course if the rpm of the engine drops as a result the ecu might try to compensate and increase the time the injector is open.

[boscoe99]

If the engine is running and you have 41 psi then the regulator is defective or is disconnected from the intake manifold. Wouldn't it be simpler to fix the problem than to try and do an end run around it?

If you start messing with leaning out the air/fuel mix you will have a much bigger problem on your hands. Let us know when you have nil compression in some cylinders.