2008 F60 Stall

[kaliann1]

I don't have a manual, and I did not have a pressure gauge, but I am mechanically inclined. I know that injectors don't operate with no or to little fuel pressure. With the pressure regulator valve stuck open, as I found out by blowing through it. The fuel pump is just recirculating the gas, and not creating enough fuel pressure to make the injectors and vapor canister work. I know I need ignition also. Remember this all happened when I throttled back. Before that the motor was running fine. I think what happened was when I throttled back the resulting quick increase in vacuum caused the pressure regulator to stick open. Then I had no fuel pressure and the motor stalled, and would not restart because the injectors need fuel pressure to operate. I am going to check it out with a pressure gauge to make sure it's OK. I be sure to post the results of the testing.
Thanks again for the help

[rejesterd]

Just saying making up names of parts will confuse people,
especially new people to motors and then they start looking for the part you made up

If you can find Yamaha's term for it, I'll start using it. But there's only one line that goes from the pressure regulator to the air intake, so it shouldn't be too confusing.

[99yam40]

there was a good discussion on this some time back and they called it a Vacuum sense line.
here is a little of what was said


and OP please do report back what you find out it can help others that have like problems in the future

The variable pressure regulator is not part of the acceleration control system. The regulator is simply designed to maintain a given pressure differential between fuel pressure and intake manifold pressure. Let's assume an absolute fuel pressure of 55 psia with the motor not running. The intake manifold pressure will be nominally 15 psi which results is a pressure differential of 40 psi (55 psia minus 15 psia = 40 psia).

The motor is started and run at an idle in which case let's say the intake manifold pressure drops to 6 psi. The variable pressure regulator being tied to the intake manifold pressure drops from 55 psia to 46 psia. Therefore, the pressure differential between the fuel pressure and the intake manifold air pressure remains at 40 psia.

The ECU is expecting the pressure regulator to make the necessary adjustments in order to maintain a certain pressure differential. The ECU then considers manifold air pressure, engine RPM and throttle position angle openings and rates of change, to vary fuel delivery and timing for acceleration control.

All of this does not help the owner of the motor. What would have helped is if Yamaha had a range of values for fuel pressure as a function of varying manifold pressures in the service manual. All they basically say is that the fuel pressure should go lower as the intake manifold pressure goes lower.

He states his problem as "as I advance to WOT it drops to about 20 psi". This is contrary to the way a fuel pressure regulator tied to an intake manifold is supposed to work. As the motor is advanced to WOT the intake manifold air pressure should be increasing and so too should the fuel pressure. His dropping to 20 psi indicates a problem with the pressure regulator IMO.

[rejesterd]

I don't have a manual, and I did not have a pressure gauge, but I am mechanically inclined. I know that injectors don't operate with no or to little fuel pressure. With the pressure regulator valve stuck open, as I found out by blowing through it. The fuel pump is just recirculating the gas, and not creating enough fuel pressure to make the injectors and vapor canister work. I know I need ignition also. Remember this all happened when I throttled back. Before that the motor was running fine. I think what happened was when I throttled back the resulting quick increase in vacuum caused the pressure regulator to stick open. Then I had no fuel pressure and the motor stalled, and would not restart because the injectors need fuel pressure to operate. I am going to check it out with a pressure gauge to make sure it's OK. I be sure to post the results of the testing.
Thanks again for the help

Nice find on the pressure regulator. Ours (I'm pretty sure) are exactly the same, so I look forward to your update. If the fuel pressure is still too low, then maybe replace the VST internal filter and have the injectors cleaned. Also replace the fuel strainer which is just downstream from the mechanical pump. In the updated service manual, it says that should be replaced every 100 hours. It's something they added to the maintenance chart. If the pressure regulator got gummed up, it's possible those other components are partially clogged too.

[kaliann1]

When I purchased the the boat and motor new in 2008,it came with 20 gai. tank, and fuel filter/ water separator. I had changed it and the small one on the motor in March of this year.

[rejesterd]

When I purchased the the boat and motor new in 2008,it came with 20 gai. tank, and fuel filter/ water separator. I had changed it and the small one on the motor in March of this year.

Right.. in addition to the small filter on the motor, there's also a strainer that sits on the valve cover along with your mechanical fuel pump. It's behind a metal bracket so you can't really see it until you remove that. I doubt it's a large contributor (if any at all) to your problem, but it's probably due for replacement at this point.

[rejesterd]

there was a good discussion on this some time back and they called it a Vacuum sense line.

Yes, it's part number 6C5-13542-00-00 - "vacuum sensing hose". Yay.

[kaliann1]

I looked for a service manual online to download. I had no luck on that. I called a yamaha dealer. They want me to bring it in at a high price per hour. I decided to order the Yamaha Boat Marine Diagnostic USB Cable Kit for Outboard/WaveRunner/Jet Boat. When I reshershed it, I found it had the manual included plus the software for the OBC that works with my laptop. I'll post the results

[rejesterd]

I looked for a service manual online to download. I had no luck on that. I called a yamaha dealer. They want me to bring it in at a high price per hour. I decided to order the Yamaha Boat Marine Diagnostic USB Cable Kit for Outboard/WaveRunner/Jet Boat. When I reshershed it, I found it had the manual included plus the software for the OBC that works with my laptop. I'll post the results

YDIS is good to have, but it won't tell you anything about fuel pressure. It can tell you if your injectors tick when you energize them, but that's about it with respect to the fuel system.

[kaliann1]

Save date	October 29 2019
ECM No.:	6C58591A31
Diagnosis
	Code	Item	Result	Condition
	13	Pulser coil	Normal
	15	Water temp sensor	Normal
	17	Knock sensor	Normal
	18	Throttle position sensor	Normal
	19	Battery voltage	Normal
	23	Intake temp sensor	Normal
	28	Shift position switch	Normal
	29	Intake press sensor	Normal
	37	Intake air passage	Normal
	44	Engine stop lanyard switch	Off
	49	Over cooling	Normal
Diagnosis Record
	Total hours of operation	164
	Code	Item	Occurred
	28	Shift position switch	12
	29	Intake press sensor	151.2
	18	Throttle position sensor	163.7

I purchased the diagnostic program. The above three items are in question. I'm still a beginner at using the program. I copied and pasted this report, with the motor off. When the motor is running it gives the conditions of each item. They all show normal so far. I haven't tried reproducing the stall event yet. I'm going to try that and see if it shows up as a code 18 at 164. something hours. I'l post my findings.

[rejesterd]

I think you can ignore the code 28, as that was very early in the life of the engine.

I've had code 29 before and it was actually due to a failing sensor assembly (i.e. the MAP sensor). Replacing the sensor solved this, but this is not a common issue as far as I know. So I wouldn't recommend this as a first step. This code could also indicate an intake manifold leak (which I've also had), a stuck ISC valve or a faulty TPS. All those things could 1) cause stalling and 2) convince the computer that the intake pressure isn't where it should be.

Since you also have the TPS code, I would look at the throttle body first. See how dirty it is. If it looks clean and the throttle plate doesn't look bent, then I would test the TPS voltage at idle. It should be around 0.8-1.2 V. If you find it to be out-of-spec, that might be your problem (and replacing it might fix it).

However, given the issue you found with the pressure regulator, there might be other areas in the fuel system that need servicing. I think it's worth checking the fuel pressure in addition to checking the TPS voltage.

Please do post any more reports you save, as those serve as a good reference for others here.

[kaliann1]

H

Save date	October 30 2019
ECM No.:	6C58591A31
Diagnosis
	Code	Item	Result	Condition
	13	Pulser coil	Normal
	15	Water temp sensor	Normal
	17	Knock sensor	Normal
	18	Throttle position sensor	Normal
	19	Battery voltage	Normal
	23	Intake temp sensor	Normal
	28	Shift position switch	Normal
	29	Intake press sensor	Normal
	37	Intake air passage	Normal
	44	Engine stop lanyard switch	Off
	49	Over cooling	Normal
Diagnosis Record
	Total hours of operation	164
	Code	Item	Occurred
	28	Shift position switch	12
	29	Intake press sensor	151.2
	18	Throttle position sensor	163.7
Engine Monitor
	Monitor Item	Result	Unit
	Engine speed	1093	r/min
	Intake pressure	37.24	kPa
	Intake pressure	10.94	inHg
	Atmospheric pressure	1016.1	hPa
	Atmospheric pressure	30.1	inHg
	Ignition timing	ATDC 5	deg
	Battery voltage (12-16)	14.7	V
	TPS voltage (0.5-4.5)	1.056	V
	Throttle valve opening (0-90)	8.9	deg
	ISC valve opening	41	%
	Fuel injection duration	1.89	ms
	Water temperature (below 90)	63.3	°C
	Water temperature (below 194)	146	°F
	Intake temperature (below 70)	38.5	°C
	Intake temperature (below 158)	101.3	°F
	Engine stop lanyard switch	OFF
	Shift position switch	ON
	Oil press switch	OFF
	Dual engine system switch	OFF
Data Logger[Engine operating hours according to engine speed]
	Engine speed	Time[h]
	- 1000 r/min	46.7
	1000 - 2000 r/min	43.9
	2000 - 3000 r/min	13.6
	3000 - 4000 r/min	2.9
	4000 - 5000 r/min	31.8
	5000 - 6000 r/min	25.6
	6000 - 7000 r/min	0.1
	Engine hours	164
Data Logger[Data comparison graph]
	Engine speed[r/min]	Battery voltage (12-16)[V]	TPS voltage (0.5-4.5)[V]	Water temperature (below 90)[°C]	Intake pressure[kPa]	Oil press switch[0:OFF 1:ON]
	1200	14.94	1.07	64.2	37.5	0
	1200	14.65	1.07	63.3	36.5	0
	1200	14.87	1.07	63.3	37.5	0
	1250	15.01	1.07	63.3	36	0
	1050	14.94	1.05	64.2	37.5	0
	1000	14.58	1.05	63.3	37	0
	1000	14.72	1.05	63.3	37.5	0
	1000	14.87	1.05	63.3	38	0
	1050	14.94	1.05	63.3	37.5	0
	1000	14.87	1.04	64.2	37.5	0
	1050	14.58	1.04	63.3	38	0
	1000	14.87	1.05	63.3	37.5	0
	1000	14.79	1.05	63.3	37.5	0

Here is a report with the motor running that I did on Oct.30, at 164 hours.

[99yam40]

that is a lot of hours under 2 k hours

[rejesterd]

1093 rpm is normal just after startup, but after warmup it should be closer to 750-800. Looks like your temp is already up to ~150F, so I think the idle should be a bit lower.

The TPS looks like it's within spec though, so I wouldn't replace it at this point.

Everything looks normal except for the idle speed. This is where you need to get the service manual and check the linkage & throttle body imo. The high idle with that TPS error code could be due incorrect linkage or a damaged throttle plate/spring.

But did you ever measure the fuel pressure after you inspected/cleaned the pressure regulator? I think that's still worth looking into.

[kaliann1]

I think I had the RPM's manually bumped up to warm the motor quicker at the time.