1997 Volvo Penta 4.3 GS Very rough at low rpm and dies if brought back to neautral

jrgcbg40

Seaman Apprentice
Joined
Apr 29, 2007
Messages
35
Hi just another update, The Carb is rebuilt and adjusted, while I was waiting on the kit I tested the ignition wires and they all read no continuity! I thought my meter was broken so I went to my neighbors (master electrician) and he tested them with his Fluke meter with the same result. So replaced the wires and cleaned up the distributor.The new wires were rated at 250 ohms per foot and were right on when I tested them. Now it runs much better and idles with no gas leaks. It still doesn't seem quite right though. I let it idle for 30 minutes and then checked base timing.When I hooked the shunt up to B+ the engine ran crappy and it was set at around 4 BTDC.When I unhooked the shunt it ran better but the timing was off the scale. The "D" in BTDC was at the pointer and when brought up to 2500 rpm it only advanced to the "C" in the BTDC? Idle speed was at 800? Am I being paranoid?
I am also hearing a rattle noise on the left side of the engine when decelerating? I can feel it with my hand on the riser. Valve adjustment?
Should I start a new thread with the rattle?
Thanks, I know you must all be busy with everyone asking questions. I will attach more videos of how the engine is running and the rattle sound.

http://youtu.be/8OjxEETDcGg

http://youtu.be/s4ybDrejNjk
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
There is only around 12 degrees advance in the distributor. Your base plus 12 is your total advance
 

jrgcbg40

Seaman Apprentice
Joined
Apr 29, 2007
Messages
35
Thank You Bruce, so I guess the timing is working correctly. Should I start a new topic for the rattle noise?
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
Didn't hear the rattle. Vacuum test looks good. Get those tie wraps off your spark plug wires with so close together like that it can induce misfiring
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
Get some spark it wire looms to keep the wires separate
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
Get some spark it wire looms to keep the wires separate
 

jrgcbg40

Seaman Apprentice
Joined
Apr 29, 2007
Messages
35
Thanks Lou. I did a search for "spark it" wire looms but didn't come up with anything? I do see some generic wire looms and will pick some up. I also replaced the ignition coil this morning as it failed one of the tests. I believe it is running great at this time. The rattle is coming from the riser / elbow area.I checked for the flappers and they were gone. I took out the hinge pins and looked down the Y pipe with a mirror. I didnt see any blockage. I also ran my garden hose down both sides and water was coming out of the bellows and by the prop. I took the prop off and looked up that port and it was clear as well. I put some silicone on the holes where the pins were and put it back together. I thought the elbow might have been hitting on the power steering line but I put my hand between it and it was not hitting. Can I run it briefly without the elbow to see if the sound disappears? I added a link to the rattle sound. Thanks for all the advice.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
If your wires are in good condition, you don't need those spreader bars. They don't do anything other than make the wires routed neatly. If you are really worried about your spark plug wires arcing, run the engine at night sometime and look in the engine compartment and see if you see anything. If you don't, you don't have a problem. Autos have way more of a problem because the heat destroys the insulation. You don't have that problem with a boat.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
Silly iPhone that should have said spark plug wire looms. If 2 wires that are adjacent in the firing order are right on each other it can cause a cross fire. May not be an issue here but that's the theory
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
My straight six Lexus has all the spark plug wires running parallel to each other for the length of the block. Not an issue.
 

jrgcbg40

Seaman Apprentice
Joined
Apr 29, 2007
Messages
35
Ok great. The wires are brand new so no arcing at this point. I was thinking of cars too,but the boat doesn't get that hot. Hopefully I can water test it soon. Opened up camp and we had a freeze warning! Brrr, feels more like fall. Thanks for all the help. I'm getting to know my engine pretty well now.
 

jrgcbg40

Seaman Apprentice
Joined
Apr 29, 2007
Messages
35
Hello experts~ I have one more question and then you can put this thread to bed. I purchased a new (advance) timing light. With the shunt plugged in to B+ at operating temperature and 800 rpm I set the timing to 1 BTDC, the engine did not like that at all. With the shunt disconnected 875 idle rpm the timing was 21 BTDC and at 3000 rpm Timing was 31 BTDC Do these readings seem normal? I don't want to burn a hole in a piston by having wrong settings. Hoping to get it in the water this weekend. Thanks to everyone for help and advice.
 
Top