Problem with 5.7 gxi 2006

[doadonut12]

registered here too see if someone else has had similar issues. i have a shop at a drystack and this boat is kickin my butt.

boat runs great....once you get it cranked. to start the boat you have to crack the throttle (just like when the IAC is bad) once running it will idle all day long and runs good....really. the issue that i found is after a failed start up the plugs are soaked in fuel. Once you get it to crank and idle for a few min and shut the boat off i can pull the plugs and they look great.

I have changed or tested every thing except the long block, (i had another boat here that i could swap parts with). i changed cam sensor, crank sensor, iac, tps, map, knock, pcv(i changed the pcv and the problem seemed to go away...until i drove it the next day and the problem came back). new cap and rotor.....rail pressure is at 60....odd ball is low speed is 15psi but i dont think this will cause my issue.

I pulled the fuel rail, all injectors work great, none are leaking or anything ~sigh~. Changed ecm as well with no change.

I suspect a vacuum leak but have not found one...any suggestions?

 

[muc]

Re: Problem with 5.7 gxi 2006

When you say "low speed is 15psi" do you mean low pressure pump is 15psi?
Have you checked the pressure regulator filter and removed it per service bulletin?
Have you tried swapping complete fuel pump assembly from motor to motor?
Do you test run both motors when you swap parts?

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

Yes low pressure pump. regulator screen was clear, and swapped from other boat. Didnt change pumps, didnt think that would cause an issue at start-up. did run other boat with problem boats parts.

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

just re-read your question on regulator....remove the screen? no i did not. this is something i asked my volvo dealer to let me know about any bulletins on this engine and they gave me none....i guess how i found my way here

 

[muc]

Re: Problem with 5.7 gxi 2006

Might want to swap the fuel cells ---- shouldn't matter but your in this deep so couldn't hurt.
Do you have scan tool? What is the 5v ref doing during cranking?

PS. When I say cranking I mean while the engine is rotating with the starter motor, not running. You can unplug both fuel pumps to keep the engine from starting so you can watch 5v ref

 

[muc]

Re: Problem with 5.7 gxi 2006

Post serial number and I can check for service bulletins.

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

yeah i have scan tool, ill haveto check it again man, i cant remember what it was reading, ive been trying all kinds of stuff. will get back to you on that. just a note i found this interesting tell me what you think.

so i took the iac off the good boat and put it on bad boat, first crank up it fired right up and had a high idle then settled down to 600rpm +-, turned the boat off and she woundnt start up again. put good boats iac back on and it had the same issue and wouldnt start on first try, but it did crank on second try and idle was eratic and took it a few seconds to settle at 600+-....figured id throw that in there.

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

Post serial number and I can check for service bulletins.

ok.

 

[muc]

Re: Problem with 5.7 gxi 2006

Yes IAC would be first guess.
What scan tool are you using?
Most will have “IAC reset” do that test while engine is running at idle speed --- RPM’s should speed up and slow back down, but engine shouldn’t die.

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

Yes IAC would be first guess.
What scan tool are you using?
Most will have ?IAC reset? do that test while engine is running at idle speed --- RPM?s should speed up and slow back down, but engine shouldn?t die.

it does die

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

its a techmate. update done last year

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

Post serial number and I can check for service bulletins.

5.7 gxi-f 3869260 4012165728.

 

[muc]

Re: Problem with 5.7 gxi 2006

The bulletin about the fuel pressure regulator is --- parts bulletin P-23-7-3 – it talks about removing the screen and replacing it with an e-clip.
When you run IAC reset with the IAC from the good engine installed, does it also die?
I assume you have checked for spark when it won’t start?
Might want to take a look at 5v ref while cranking and IAC count at idle.

 

[doadonut12]

Re: Problem with 5.7 gxi 2006

What were the issues they were having that they want you to get rid of the screen? I know they sometimes get blocked up with the black stuff but just wondering if there was something else? But i will def do that, it will probably be next week when i can get that boat back in my shop since i sent it back (i have limited rack space and i was getting nowhere with it)

Yes boat still dies with good IAC....

Yup good spark at crank up. I will check the 5v ref when i can bring it back and let you know....thanks for your help. IAC count...see thats an interesting one, with the original IAC its at like 80, with the good IAC its at about 115-120...

What is cam retard suppose to be on these?

 

[muc]

Re: Problem with 5.7 gxi 2006

The screen was plugging up and causing high fuel pressure. “fuel soaked plugs”
IAC counts seem normal.
Volvo EGC manual 7743614 page 73 wants cam angle set to 45 degrees +/- 5 degrees

 

[wrench 3]

Re: Problem with 5.7 gxi 2006

Interesting that no one is mentioning the CTS. I've found it to be one of the most common causes of over fueling at start up. I don't know if that engine has a closed loop system, but if it does, onces the O\2s kick in the mixture gets pulled back in line.

 

[muc]

Re: Problem with 5.7 gxi 2006

Yes coolant temp sensor can cause over fueling as can TPS and MAP. That’s why a scan tool is so important.
No O\2s until 2013 when the cats got added to marine engines.

 

[Fun Times]

Re: Problem with 5.7 gxi 2006

if applicable on your engine model, have you removed the/any small vacuum hoses going to the fuel regulator or fuel pump assembly looking for signs of excess fuel.

Was looking for something and I ran across this note on page 3-8 about the reservoir vent hose and regulator vent hose and thought of this thread. Just throwing it out there just in case. good luck.

Boatinfo - Volvo Penta BY series engines EFI Service Manual

 

[muc]

Re: Problem with 5.7 gxi 2006

Good point Fun Times, part of checking fuel pressure involves removing the vacuum line to the regulator and checking for fuel in the line and also checking that the fuel pressure goes up 2-4 psi
I should point out that the BY engines used a VST system and the OP has the newer style MOAS system. So the OP should look in a different manual for trouble shooting.

 

[Fun Times]

Re: Problem with 5.7 gxi 2006

I should point out that the BY engines used a VST system and the OP has the newer style MOAS system. So the OP should look in a different manual for trouble shooting.

Thanks Muc and you are correct the manual referenced above is not for this engine model in question. It was only meant to be a guide of what to look for should this engine model have them. That mentioned I believe the most current service manual for this later model engine is not available anywhere online any longer since Don is no longer with us. The manual linked below Volvo part number 7743372 says it covers 5.7 GXI-F but when you check tune up specifications it falls short of mentioning 5.7 GXI-F

Muc, if possible in your spare time, would you be able to look up and confirm what the 5.7 GXI-F fuel systems low fuel pump fuel pressure is? I'm used to seeing the older system down around 8 psi. 15 psi seems high to me and can't be overlooked if so. Thanks.Boatinfo - Volvo Penta 5.0 and 5.7 Engine Service Manual