Intermittent Running. All or nothing scenario.

[MAW31]

Dealing with an intermittent running issue here. Its all or nothing. When it runs its smooth, strong and great.
2000 19Ft Regal w/ Volvo/Penta SX outdrive and 4.3GL Volvo motor #4110188221 RWTR.

Had a situation about a week ago and thankfully we were very very close to the marina. While at minimum speed, the motor simply cut-out. no sputter, no nothing.
motor cranked great, but motor was dead to the world.

Thought I found the problem in the Main Wiring Harness Connector...while dockside, and inspecting everything, I wiggled the main harness connector (among other things), turned the key and voila! started and ran great. cleaned up connector, reseated it and all seemed good.

went out next day, short trip, no probs at all. yay. docked boat, returned 2 days later. and motor has never even coughed since.

Backing up a bit, when it does run, I barely crank it and it jumps to life. it'll crank like crazy now but never ever shows any sign of running, no sputter, no cough, no backfire, nothing. Has plenty of fuel and battery is new and charged full. (on a tender)

I'm about to just swap out the ignition switch because I cant think of anything else that would be causal to what I'm experiencing.
Is there an ignition switch test?

What else could it be...? When it runs, its flawless. Really quick starts. Using same gas as before. good battery charge. oil level is good.
Spent the morning again and now feel like I'm chasing my tail.

any help greatly appreciated. thanks.
Matthew

 

[alldodge]

The good thing is it's not hitting, so you should be able to find what's wrong. Your getting fuel so the next thing is to find out if your getting spark. Pull the coil wire and put it next to a ground and check for spark

 

[HalfFish5087]

Little early to start replacing stuff. I would get a 12V test light and start at the ignition, coil, and kill switch. My $ is on the kill switch though.

 

[StingrayMike]

I had the same issue on my 5.0 gxi. Turned out it was the throttle position sensor.
I did all the same troubleshooting, thought it was my ecm connection. Checked all grounds, verified voltages and fuel pressure.

 

[Scott Danforth]

GL should be carbed

Way to early to be changing parts

Check for spark, could be dash safety switch, bad connection, stuck relay, etc.

Also check quality of fuel (check contents of fuel filter) you could have a bunch of water in there and water doesn't burn.

 

[skydiveD30571]

With a carbed (not EFI) engine, you know it's a fuel or spark problem. Since you said it's either really good or nothing at all, I would lean to an intermittent spark problem. As said above, use a meter or test light, and check the ignition cylinder at each point as you turn the key. Also check for spark like Dodge said.

Here's a copy of your OEM service manual for the ignition and fuel components. You'll find some great info and troubleshooting tips here. If you click "back to library" at the top right corner you'll also find most other Volvo manuals including the one for your SX drive. All free
http://boatinfo.no/lib/volvo/manuals/wt_elect.html#/0

 

[Senior B]

when you turn the key to on/run, do you get your engine alarms? I ask this can direct to kill switch problem.