Volvo penta 4.3 gxi-q 2011 poor performance

[Rawbd]

Volvo penta 4.3 gxi-q 2011 poor performance. Hey there looking for some help. My motor just went out of warranty. It has 106 hours on it. It's been running rough since the season began. (Early May) It won't rev over 3900 rpm. It stumbles out of the hole and just isn't as responsive as it used to be. Sometimes on take off with a load in it at wot it shakes badly. Fuel filter has been changed twice. I changed the plugs, I found number 1 fouled / black. With four people in the boat it will barely plane still even after changing the plugs. I've ruled out the fuel as I've ran it near empty and just put in 15 fresh gallons. I took the plugs out again and found number 1 black again. I checked contact points in the distributor and they look fine. Firing order is good. Any thoughts? Below is the serial number info. I'm thinking the #1 injector is bad or the coil. 40869310 A167853 4.3gxi-q

 

[John2037]

Pop off your fuel pressure regulator and check it out - there is a screen that gets clogged and Volvo actually has a mod that removes the screen and replaces it with a spacer. If that's fine, I would test your fuel pressure - the high pressure fuel pump craps out if they sit for a long time

 

[Rawbd]

Thanks I will check that out.

 

[Rawbd]

Just an update on this. I cleaned the filter in the regulator. It wasn't that bad but had some black stuff on the fine screens. I then pulled the connectors off each injector, I found corrosion on the number one cylinders injector connector,. I cleaned that up and checked and cleaned up the other five cylinders injector connectors, and then the motor ran great again. I could get it to rev to 4700rpm and hit about 48mph on the speedo. I'm very happy now that it's back to normal. Thanks.

 

[Loveda4]

For others with similar issues:
My issue:
2011 4.3 gxi-q would take 5 min to get on plane. Started after only a second or so and didn’t run overly rough when idling out of the slip, but would only get to 2700 rpm at wot until I pushed it for 3-5 min. Once planed at 3200 rpm, would eventually get to 4000 rpm wot after another 5 minutes. After, would come off and on plane easily, but once cooled, issues resurfaced.

root cause and corrective action:
Found the spark plugs to be original. Napa and oreiley cross references the penta part numbers and found what I needed for $75: Changed plugs, distributor cap and rotor (not wires because they looked good and Napa didn’t cross reference the right ones). Made an enormous difference immediately. Can hit 5000+ Rpm wot. Planes right away with zero hesitation, 30 mph at 3500 rpm on a Glastron ds-205 with a 4 blade prop on an sx-a. Engine is smoother than expected and starts immediately.

 

[stouchton]

I was just going to say that when you have 1 fouled plug, usually an injector issue. Could be oil, but easy to check injector first.