Volvo Penta fuel injection problem

[pdowning]

Before starting my VP 5.0 after a long spell of sitting idle, I replaced the low pressure fuel pump and also took off the throttle body fuel injector, took it apart and cleaned everything with carb & choke cleaner (maybe I should not have done that as I have no experience with TBFI's). Now when I start the motor it idles fine, but when I give it gas it revs for a second then drops over and over again until it backfires and dies. Did I screw something up? Is it sucking in air somewhere? I don't know. Sorry to be so longwinded, but any advice would be very helpful.<br /><br />Thanks,<br />Pat

 

[newport dave]

Re: Volvo Penta fuel injection problem

Pat,<br />What year and/or serial number is this engine?<br />How old is the gas that you are using?<br /><br />When you disassembled and cleaned the throttle body did you spray the parts with cleaner or did you soak them? <br /><br />Hoping you did not soak the Throttle Position Sensor (TPS) or Idle Air Control (IAC)valve. They can be damaged by soaking in cleaner.<br /><br />In any event, The first step would be to check the fuel pressure at the high presssure test point. Do you have a fuel pressure gauge?<br /><br />Dave

 

[pdowning]

Re: Volvo Penta fuel injection problem

Thanks for the reply. The gas is about 6 months old. The engine year is 1999. I did not soak any parts, just sprayed heavily. I am going to buy a fuel pressure guage and test this weekend. What should the pressure be?<br /><br />Thanks

 

[newport dave]

Re: Volvo Penta fuel injection problem

For a 5.0GiPEFS (I think that is what you have) is 29PSI plus or minus 2PSI at key up, and within 1PSI of that reading at idle.<br /><br />Dave

 

[TilliamWe]

Re: Volvo Penta fuel injection problem

Idle Air Control (IAC)valve.

This should not be your problem. If it was this component, the problem would most likely occur when reducing throttle (quickly or slowly) back to idle. <br />

Now when I start the motor it idles fine

That says to me that IAC is okay, and that you do not have an air leak. Or at least not much of an air leak. If you did have an air leak problem, the idle would be way high, in my opinion.<br /><br />I totally agree with the fellows before me to check fuel pressure first. If that checks ok, I think you need to check the Throttle Position Sensor, and also the timing advance.

 

[TilliamWe]

Re: Volvo Penta fuel injection problem

oh, and get some fresh gasoline in there before you do anything else!

 

[pdowning]

Re: Volvo Penta fuel injection problem

Thanks, there is 3/4 tank of gas in a Larson Cabrio. It is going to be a pain to drain. I see you are from Peoria, I grew up there and my family still lives there.

 

[Don S]

Re: Volvo Penta fuel injection problem

There is nothing wrong with 6 month old gas that would cause your problem. Obviously when you took it all apart and put it back together you did something. Perhaps it was the carb cleaner, perhaps something is put back together wrong, or it was damaged in the whole process.<br />Get the Volvo service manual and start checking each item you messed with. It could be anything.

 

[TilliamWe]

Re: Volvo Penta fuel injection problem

omega, I was living in FL before I moved to Peoria, six years ago!<br />Does your family boat here in Peoria?<br /><br />DonS, I know that the 6 month old gas shouldn't be the problem, but I was try to eliminate even the possibility of it, by recommending new gasoline.

 

[outboardguy]

Re: Volvo Penta fuel injection problem

If you are going to recommend new gasoline it is wiser to suggest to get a small outboard tank to hook up for testing purposes to eliminate his big tank. Where I work we have to charge $10 a gallon for bad fuel disposal.