Engine Stalls at low revs

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Any help appreciated

2007 Volvo Penta 5.7gi-g

Engine stalls at low revs at idle
Starts Fine
If I keep revs above 900rpm its OK
 

ericga

Petty Officer 1st Class
Joined
Mar 4, 2012
Messages
213
You can start by cleaning the tip and passage and give it another try. If you replace the part with an aftermarket, make sure you get the right one as the pintle travel distance could differ (similar part, different application).
 

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Guys could it be the low pressure fuel pump,been told a lot of issues with the paint coming off inside the pump.Been on the boat this morning and there is a high pitch winning sound coming from the pump, both pumps are not getting hot.Connected the Rinda scan tool and not showing any faults.
The only way I can get it to tick ove is to adjust the throttle cable it running at 850rpm at idle and doesn't cut out.Just priced the fuel cell unit and over here in the U.K your looking at ?650 😭 Can you strip the low pressure pump down ? I removed the IAC valve and it nice & clean
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
It runs fine above 900 rpm's and will not idle under that, I'm still thinking Idle speed valev.

The paint in the fuel cells was several years back, and all should be fixed by now, and it was a Merc issue. Your boat is fuel injected which means it needs a supply of High pressure fuel to run. If the low pressure pump was the issue, it would have more trouble at higher rpm's then low

You could also see about outing a vacuum gauge on the motor to see if there is a leak
 

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Cheers Bud
Any information on how to carry out a vacuum check, never done one before
 

ericga

Petty Officer 1st Class
Joined
Mar 4, 2012
Messages
213
Inspect the fuel pressure regulator for clogging. A common problem in mid-2000 Volvos.
 

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Ericka
Is the fuel regulator serviceable, can I just clean it ?
 

ericga

Petty Officer 1st Class
Joined
Mar 4, 2012
Messages
213
You can clean the screen. Volvo recommend to replace it with a C-clip. See bulletin P-23-7 no. 3 version 1 (google). Symptoms are more hard to start, weak acceleration and poor performance.

For the IAC, make sure the connection is good and inspect the connector for damage. The passage where the pintle travel and sit must also be clean. The IAC should have either an o-ring or a gasket to prevent air leak.
 

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Just ordered a new IAC valve, will keep you all posted.

what should the hi & low fuel pressure be, and when do I take the readings at tick over 600RPM ?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
I'm finding, Low pressure pump should be 8 +/- 4 PSI, High pressure pump should be 50 - 60 PSI from idle to WOT and should be steady
 

ericga

Petty Officer 1st Class
Joined
Mar 4, 2012
Messages
213
[FONT=&quot]Low pressure pump should be[/FONT][FONT=&quot] [/FONT][FONT=&quot]+/- [/FONT][FONT=&quot]8 PSI and you should have 50-60 PSI at the fuel rail. You may have a schrader valve to hook up a fuel pressure gauge. Pressure should be constant at all RPMs.

If you purchased an aftermaket IAC compare the plunger tip. Shape and size is another variant. You may find a little piece of foam (filter) that can get dirty and restrict air to the IAC. Unlikely on your engine but you may want to check that. It's located in the throttle body hole where the IAC is installed.
[/FONT]
 

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Guys down at the boat the is weekend, I have ready a fuel pressure test kit with all the adaptors, I have the Rinda Scan Tool,a new Volvo IAC valve, a e-clip for the pressure regulator, I plan to take some pressure readings before I start replacing any of the parts,Is there anything else I should be checking ?
 

Taz59

Petty Officer 1st Class
Joined
Apr 10, 2003
Messages
304
Guys
Well went down the boat well armed.
New IAC Valve
New E Clip for Pressure Regulator
New Fuel Cell
Before I replaced anything I took some fuel pressure readings.

Low pressure reading 18psi at all revs
High pressure reading 52 psi at all revs
Leak down test on high pressure side stayed at 52 psi stopped timing it at 12mins
Changed IAC Valve made no difference still stalled
Changed E Clip still stalled
Changed complete fuel cell and ran like a bag of sh---te
Low pressure fuel pump not running, ? Went through the correct procedures on changing the fuel cell, fill filter with fuel switch ignition on & off a few time.
still no pressure,
So decided to put the old fuel cell back on got all the same readings as above.

Spent five hours down the hole and we'll pi--ssed off

What would cause the low pressure pump to run at 18psi
Non of the pumps get hot but low pressure pump is making a winding noise but not to loud

Any advice appreciated
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
Old pump, low side 18, high side 52
New pump, low side not running

This doesn't make since
Would say even though the low side was to be 8 psi, it being 18 would not tell me that this would be an issue. The low just feeds the high, so it should have no effect with injectors or their control. The low side must be having trouble sucking fuel (drawing air). How's your anti siphon valve?
 
Top