5.7 2004 model back fire at start up

[Mark Mason]

5.7 will not start unless I engage the throttle forward. It acts like it is starving for fuel. As it cranks, it back fires. Once started it works fine.

 

[Fun Times]

Hi there, welcome to iboats!

Do you know the full model number of your 5.7? For example 5.7 Gxi-J.

This is a Volvo engine correct?

Typically the first suspected engine feature to fail is the idle control valve (IAC) when you find that opening up the throttle slightly during engine crank helps start the engine.

 

[Mark Mason]

The Volvo 5.7 is model GI-E. I will watch the IAC at start up. A bit more information is when cranking the engine it seams like it is starving for fuel because of the back fire and when it does eventually start the idle takes about 5 seconds to settle in. The problem is also inconsistent whereby sometimes it starts fine when cold and sometimes not. Also when hot, very inconsistent. Thanks much for your help.

 

[ericga]

Have you check the fuel pressure? I wouldn't be surprise if the fuel filter is saturated or the pressure regulator is clogged (common on mid-2000 Volvos).

 

[bajaunderground]

What elevation are you running at? what type of fuel (octane) do you run? Check as suggested above, but what can happen at shut-down is the fuel boils due to the residual heat of the motor and fuel pumps...it boils it out of the fuel cell (like a bowl of sorts) and causes what you are describing. I was advised to run 91 octane here in Colorado (I boat @ 3,800') and we have 85, 87 and 91 octane rating. The 85 boils at like 90*. I only run 91...

 

[Mark Mason]

If you mean the water separator, I will change it. I cannot locate another in line filter on this model. I will check the pressure regulator. What about the IAC theory?