Engine Stalls at low revs

[ericga]

Also check the fuel tank vent for clogging. You can run directly from a gas can and see if things improved. You may have a clogged or damaged pick-up tube too.

 

[ericga]

Forgot to ask. How dirty was the regulator screen?

 

[Taz59]

It looked OK but fitted the eclip just incase.

If I set the idle rpm to 800 it runs fine.

If there was a fault with the fuel supply why am I getting 18psi on the low pressure pump ?

 

[alldodge]

If I set the idle rpm to 800 it runs fine.

Doing this means the IAC is not controlling the idle, your using the stop screw to adjust. My thought is either a vacuum leak, or bad connection on IAC, Throttle Position Sensor, or ECM. Puzzling, is there are no codes. Is your tach accurate?

If there was a fault with the fuel supply why am I getting 18psi on the low pressure pump ?

The 8 psi comes from the manual, and not knowing enough about VP it could be this is minimum, don't know. That said, I don't see an issue if the low supplies more pressure to the high, just means it doesn't have to work as hard

 

[Taz59]

No fault codes
I can use the Rinda tool to test the IAC I can increase the RPM 100rpm at a time, and it's working.

Also I can check the RPM on the Rinda tool

 

[alldodge]

OK your using the tool to increase the rpm's

Does it smell like its running rich? Is the flame arrestor dirty? Have you looked at the plugs?

 

[Taz59]

New plugs,leads,dizzy & rotor and clean flame arrester

 

[alldodge]

Hey muc can you provide any insight ?

 

[ericga]

Hummm.... throttle position sensor. That could well be the problem. You should be able to see the values with the Rinda tool. It can easily be tested with a multimeter too (you'll need thin probes).

 

[Taz59]

Ericga
Back at the boat Friday so what should I be looking for on the throttle position sensor.
Yes I can check with the Rinda tool but what figures should I be looking for ?
What should it be reading at idle ?

Do you know why my low pressure pump is giving out 18psi when the manual says it should be 8psi ?

It's not related but I will also be changing my manifolds & riser as they are leaking 10 years and have been in salt water.

Thank guys for all your help so far.

Let's hope I get to the bottom of this.

 

[ericga]

As long as the low pressure pump keeps the high pressure one happy I wouldn't be too concerned about it for now.

Could you have a damaged/defective/wrong fuel filter type? What about the anti-siphon valve and fuel tank vent?

 

[Taz59]

Brand new fuel filter, will check anti - syphon vale and fuel vent at the weekend

 

[Taz59]

Guys took some readings from my Rinda Techmate, Engine stalled after 10 minutes

	2007 Volvo Penta 5.7Gi-G Serial No 4012215965
	Rinda TechMate Scan Tool
	Ignition On Engine Stopped	Engine Running
Engine Not Running
Engine Starts	527
Operating Hours	128
Engine Speed	0 RPM	593-623 RPM
Des Idle Speed	900 RPM	600 RPM
Target Eng RPM	900 RPM	600 RPM
IAC Position	193	59-63
CAM Retard	0.0 deg	12.0 - 12.5
MAP Volts	4.8 vcd	1.88 - 1.95 vcd
Barometric Press	30.3 inHG	30.3 inHG
Barometric Press	14.85 psi	14.87 psi
Manifold Press	30.3 inHG	14.0 - 14.3 inHG
Manifold Press	14.85	6.90 - 7.07 psi
Engine Load	89.50%	25.6 - 26.4 %
INJ Pulse Width	73.3ms	4.5
TCP Actual	0.00%	0.00%
TCP Commanded	0.00%	0.00%
TP Commanded	75%	19.2 - 21.0 %
TP Actual	0.00%	0.00%
TPS Volts	0.65vcd	0.64vcd
Throttle Position	0.00%	0.00%
Min TPS 1 Voltage	0.79vcd	0.65vcd
ECT Volts	3.42vcd	0.89vcd
ECT Sensor	55 deg F	158 deg F
IAT Volts	2.90 vcd
IAT Sensor	59 deg F	98 deg F
Oil Pressure Volts	0.58vcd	2.37 vcd
Oil Pressure	0.30psi	46.6 - 48 psi
Oil Pressure Status Low But Ignored		OK
Ign Switch Volts	11.33vcd	12.4vcd
Battery Volts	11.64vcd	12.6vcd
Spark Advance	0.0deg	2.0 - 3.0 deg
Knock Avg Volts	0.0vcd	0.0vcd
Knock Retard	0.0deg	0.0deg
Octane Rating	0.00%	0.00%
Knock Intensity	0.00%	0.o %
Fuel Flow	0.0gph	0.8gph
Trim Volts	0.11vdc	0.11vcd
EGT Switch	4.99vcd	4.99vcd
Warning Horn	Off	Off
Malfuntion Lamp	On	Off
Engine Derate	1 Off	Off
Engine Derate	2 Off	Off
Low Rev Limit	Off	Off
Fuel Relay Driver	OK	OK
Ign Relay Driver	OK	OK
Mill Driver	OK	Open Load
Tach Driver	OK	OK
IAC Driver	OK	OK
Shift Interupt	4.99vcd	4.99vcd
Inboard Neut Switch	2.74vcd	2.74vcd
Duel Helm Input	4.99vcd	4.99vcd
Master/Slave Master

 

[alldodge]

I would expect to see the vacuum above 15 and closer to 18 in Hg, and IAC would be 40 or lower

 

[Taz59]

after searching the internet and reading about all the different sensors and what could happen if they fail I came across this article, so I have ordered a new crankshaft sensor.

The most common failure for one of these sensors is when the engine is idling it will just stall. This is because the pulse width is at its widest gap because of the slower engine speed. Heat will also cause the sensor to fail because of the thin wire winding which will expand with heat and short out to one another changing the sensors resistance which will cause the sensor to stop giving a signal to the main computer. Once this happens the pulse generation to the injector and ignition systems will stop the engine from running.

A failing crankshaft sensor is famous for working when the engine is cold and then to stop working when the engine heats up. When you let the engine cool off the sensor will start working again. Testing this sensor's intermittent failure can be difficult due to its ability to start working again. Though you can test the sensors resistance using a voltmeter the true way to test the sensor is to use an oscilloscope when the sensor is hot

will keep you posted

 

[Taz59]

Well that didn't work fitted the crank shaft sensor and it's still stalling on low revs 600rpm.this was after 10 minutes
So then I fitted a new PVC Valve and it still stalled
So then fitted a new pressure regulator and it still stalled.
When it does stall the fuel pumps are still running and the high pressure is OK 52psi
I checked the Rinda and there was a fault code logged
Code 0336 Crank Input Signal Noise ????

Any help appreciated

 

[alldodge]

I'm finding

DTC 336 Crank Input Signal Noise - ECM detects more
than 1 re-sync or invalid crank signal within an 800 ms period
of a cranking cycle. Possible loose or broken connection
at the ECM or CKP or short to battery power on any of the
CKP wiring. Verify wiring, connections at CKP and ECM
- repair as required. Replace CKP.

 

[Taz59]

Hi bud

I replaced the CKP yesterday wth a OEM part, will check all connections and wiring.
What's bugging me is why is it OK above 800rpm ?
Any advice on how to check the wiring ?

 

[alldodge]

I'm puzzled myself, but a CKP is effected by how close it is to a passing metal object, in this case a cog wheel on the crank. Most cannot be adjust because they sit into a casing which cannot be moved. Not a VP guy so have not looked yours up yet, but assume it would be the same as Merc.

Checking wires for me is to ring them out with an ohm meter and look close at the contacts.

 

[Taz59]

i sent the new faulty fuel cell back and they sent me a new one back, fitted the fuel cell and so far it's been running OK not stalled once, going back tomorrow to try it again, The pressure readings for the new fuel cell are
Low Pump 10psi Old pump 18psi
High Pump 50 psi Old pump 54 psi

My thinking is to much fuel being delivered and flooding the Engine at low revs ?????