Volvo penta 5.7 gi breaking down

32carv

32carv

Well-known member
Member
Joined
Nov 4, 2006
RO Number
24150
Messages
1,309
I have twin 2006 Volvo 5.7 gi with 700 hours. Ran good when put away. Changed fuel filters when winterized. Motors started easily and ran great when put in this year. Got up on plane at 3200 rpms and ran great for 5 minutes. Port motor then lost rpms and started to pop or backfire. When on plane again and it happened immediately. Idled back to dock.

I am going to change caps, rotors, and plugs on both motors. What else should I look at?
Jim
 
Water in gas?? Filters can only handle so much.
 
Have you ever changed the plug wires since 2006, 11 years? What you have listed above is a good start especially if it has been a couple of years since those items were changed. Run it to warm the power plant up remove the plugs and then run a compression test to see if some 2017 gremlin caused an issue. Good luck!
 
Same happened with our 5.7 MerC. Distributor Cap and Rotor solved it in one case. Another time, Battery Cable Connections looked good. No evident corrosion. Still, dismantled and cleaned. Problem went away.

Cap and Rotor. Get good ones with brass Cap contacts. This is gonna sound silly, but make sure they MATCH. Most Caps seem to have a spring-loaded center contact. That calls for a rotor with a flat brass contact surface. There are (or at least were) Caps with a fixed center contact that called for a rotor with a spring contact. You want One Spring! Not springs on both parts, not parts with no spring on either.

If your VP is like our MerC, you can use Auto Supply parts, like good ones from NAPA. They didn't have to be "Marine."
 
Just bought it at the end of last year. Don't have mechanical history. Planned on tuning up anyway and bought all parts from NAPA. I filled with gas on way to lake. I'm guessing if it was a water issue, both motors would be effected. Friend had similar issue and after throwing $1500 in parts at it, including fuel pumps, it turned out to be ground wire on motor.
Jim
 
I couldn't believe the trouble that battery connections caused on ours. It's an I/O, and the first indication was that the engine would pop and miss when I operated the power trim.
 
When you change the caps and rotors , carefully inspect the main coil cable too. One of mine looked to be in new condition last week when I had same issue at cruise speed and returned on one engine. When I gave the coil wire a slight tug, it fell apart in 2 pieces in the middle where it apparently had managed to chafe minutely on the bottom of the cable and had arced to engine ground ( snapping noise when cranking ).
This was encouraged by corroded flat "crossover" caps (brass electrodes) and rotors ( last changed with new ones middle to late last summer 2016.), which added great resistance causing the coil pulse to seek a nearer path of lesser resistance.
Replaced cap , rotor and coil cable, adjusted cam retard slightly and it runs beautifully again like its mate.

If you have a Cam Retard Angle tune-up setting for that engine , you'll need a marine scan device to check or adjust it.

To see if it is a gas issue, you could remove the flame arrestor , pour a small thimble of gas down the throat, re-secure arrestor and see if it will start and run OK briefly.
If so, you might try bypassing vent, questionable quality gas, pickup , anti-siphon valve, delaminating hoses, or loose hose clamps, & all fuel filters/separators, ... by temporarily plumbing-in a clean portable O/B tank with new fresh straight gasoline to the fuel pump to see how it runs.

If you think it is electrical , you could check for steady/consistent ignition pulse when cranking with a timing strobe light on the plug cables. But check caps and rotors anyway.

There are a lot of potential causes for what you describe.
 
Got the same problem, Jim - 2003 5.7GXi stbd engine runs fine - slow and under load - till apparently warm, then starts sputtering, possible backfire; then won't work under load - have to idle back to dock.

mechanic did cap/rotor, retarded timing - no joy. hopefully he can get to it today. . .as this has been a problem for the past 3 weeks, if he can't get to it I'll take things into my own hands . . . I just hate to start replacing things at random trying to fix such a particular problem. I don't mind paying for good, timely help, but sh!t - I launched in late April hoping to have any kinks ironed out by Memorial Day!
 
first things i would do is dump out the fuel filter into a container and look for water or junk and make sure the battery connections are clean and tight.
 
Whenever an engine acts up under load, whether gas, diesel, outboard, inbiard or generator the first suspect on my list is fuel and first thing I change are the fuel filters.

In your case now knowing the history one filter may have been changed more recently than the other which would explain why only one is acting up

After that then yes... ignition
 
It really doesn't matter if filter were changed recently. a few minutes of running is all it takes if there is water or junk in the fuel
 
Less than 30 minutes of run time on new filter but I will take a look.
Jim
 
Many engines have primaries and secondaries Even gassers. Make sure you re not missing on
 
Won't have time to change out parts until Friday but pulled cap off and posts are worn with white stuff on them. Rotor also very worn. Both engines draw off same tank so leaning towards electrical.
Jim
 
Changed cap, rotor, plugs and problem seems to be gone. May have been original plugs with 700 hours. Not pretty. Thanks for all the help!
Jim
 
GREAT!!! We had over 400 hours when ours did that with ignition parts (the battery cable issue I mentioned happened later). Plugs probably would have run longer still, original AC's.

Glad you got'er done, And some Holiday Weekend left to go!
 
Update: Problem returned this weekend but I noticed significant whine out of fuel pump. Dumped out fuel filter and gas was crystal clear. Pulled tube out of tank and screen was clean. No obstruction when I blew through line. ( gas still tastes ****ty)

Started thinking about issue and remembered that it started right after I replace fuel filters in the spring. Bought them at NAPA. When I changed them, I remember noticing that they were significantly shorter than the one that were on it. Replaced with the longer Volvo Penta filters sold by marina and it runs great, 54mph without a without a problem. Loud fuel pump whine went away. Not enough fuel getting through smaller filters?
Jim
 
Crazy!

Great job finding it!

Always good to remember to go back to the most recent work done.

Please give us the Part Numbers or Pictures of these filters.

Just from the description you provided of the Ignition Parts, it needed them, too.
 
I had a similar problem and went through all the inexpensive fixes suggested here. Nothing worked permanently. The first expensive fix was to replace the HP fuel pump. Seemed to work for a few hours then the engine losing power problems returned again. The had the entire fuel cell replaced. That worked after 25 hours. If you read web reports on this, VP fuel cells have an issue where internal paint would chip off and collect in the internal filters of the fuel cell. Newer engines than mine 2001 5.7Gsi PEFS would have the problem in he fuel rail.

Some people reported good results after tearing open the fuel cell and cleaning the filters inside the cell. VP reports there are no repairable parts other than the HP fuel pump.

Just something to consider.
 
You must log in or register to reply here.
Back
Top