Engine turns but won't start

[Pete1burn]

1994 Larson 194LXi, Volvo Penta 4.3GS, DP-S outdrive.

Went out this weekend with a few people. Had the engine stopped and started a few times throughout the day with no issues. We found a small cove and anchored for some swimming with the k ids. I fiddled with my new stereo I installed on Friday a bit changing the wires around at the fuse panel. Went to start the engine when it was time to go and it just turned without starting. I had a multimeter with me and tested out the fuel pump relay which was fine. Ended up having to get a tow.

Two things I can see that might have caused this. One is the stereo. Like I said I removed one wire from the fuse panel to route it to a positive lead above the panel. Its a 2 amp fuse but all it was powering before I pulled it was the old stereo. As far as I can tell. I can't find any documentation on what that 2 amp fuse is for.

The only other thing I noticed was that the throttle control would not go into gear. I had to remove the rubber boot from the button and fiddle around with it before it engaged again. But if I'm right, the engine shouldn't even have turned if that button wasn't pushed in right?

I could smell fuel when I pumped the handle so all I can think of is no spark. But what would cause that to suddenly happen?

Could it have something to do with the 2 amp fuse? I can't imagine a 2 amp controlling something as powerful as the ignition. And like I said, the only thing it looked like it was powering in the first place was the old stereo.

Have to go up this weekend with my car to jump the battery and a friend at the camp has a hose thingy (whatever its called) so we can troubleshoot. Figured I would ask here first for some advice.

Oh one more thing: I also took the kill switch lanyard off since my kids were swimming off the stern. But we touched the wires together to be sure that wasn't it. I was also told the engine wouldn't turn if that wasn't functional, but it DID turn with the wires apart and also touching. Ordered a new one today anyway to rule it out.

Thanks.

 

[Don S]

Re: Engine turns but won't start

Do you have spark when you crank the engine?

 

[Pete1burn]

Re: Engine turns but won't start

Hey Don. I have to work on it over the weekend. Just trying to get some pointers before I go up there.

 

[Pete1burn]

Re: Engine turns but won't start

So the starter wasn't activating so I took it to NAPA who said it was dead. They didn't have a new one so I drove to the boat shop and picked one up. I also got new plugs at the same time.

Replaced the starter and the plugs and it still won't start. I had been spinning the motor before changing the plugs and I could smell gasoline on the plugs and they were wet. So I'm pretty sure it's not getting spark.

So, what might cause that? I'd like to narrow it down a bit before I go out and buy anything else like a distributor cap or rotor. Today's total was over $300. Welcome to boating I suppose.

Edit: Forgot to mention we tried some starter fluid in the carb. Nothing happened.

 

[Maclin]

Re: Engine turns but won't start

There are troubleshooting guides in the "stickies" topics at the top of this forum that will aid you in checking for spark and subsequent causes if there is none. One of the first places to start is to check for voltage at the coil with key on, then also while cranking. If no voltage then the problem may very well be in that circuit you tapped in to for the stereo, that is when the problems started right? Just sayin', how do you know what it was for if you did not check a wiring diagram first?

 

[Pete1burn]

Re: Engine turns but won't start

I've been trying to find a wiring diagram online. The fuse is a 2 amp fuse. I took a pic and will attach it below.

It can't be the neutral switch because the engine wouldn't turn if it was. The only other thing I could think of was the kill switch, but I just replaced it this morning to rule it out.

There are two wires that are not connected to anything. One is brown with a thin blue stripe and one is brown with a thin white stripe. From what I remember, these weren't connected to anything.

So, to reiterate, three things that happened from the last time it started successfully to the time it didn't:

1. Changed wires to the back of one of the instrument panels for power to the stereo

2. Took killswitch lanyard out

3. Throttle would not engage in gear. Would only move back and forth as if the neutral button was pushed.

So what items would cause only the plugs to lose power? Are there any safety switches that would cause that? As far as I remember from the one time the throttle wasn't completely in neutral it wouldn't even turn over. Could I have disconnected a wire that controlled a killswitch?

So confused. Continuing the search for a wiring diagram.

I tried to follow the instructions for testing the starting system, but I need a wiring diagram to figure out the nest of wires underneath.

 

[Maclin]

Re: Engine turns but won't start

Is this the same boat that got water in it up to the bottom of the engine?

 

[Pete1burn]

Re: Engine turns but won't start

Yes.

 

[Pete1burn]

Re: Engine turns but won't start

I'm thinking it might be the neutral safety switch. I was having trouble getting it to pop out before the trouble started. Problem is, there isn't a chart in my SELOC manual that says where the switch exactly is. It DOES say that if the switch is in the transom, and if it is not in neutral, it will cut off power to the coil. Sounds like a bingo to me. I searched through all the wiring diagrams in the book, but none of them has that switch listed. I know there is one behind the throttle control, but apparently those wires lead to another switch in the transom.

Getting ready to take it back to the boat shop if I can't figure this out. Anyone else have any ideas for me?

 

[Don S]

Re: Engine turns but won't start

The neutral safety switch controls the use of the starter, nothing to do with the ignition at all. The switch that controls the ignition would be the safety kill switch (the one with the lanyard)
What is the FULL model number of your engine? That's all the other letters after the 4.3GS.

To check for spark, Remove the coil wire from the distributor cap, hold the wire about 1/2" from a good clean ground (NOT Paint) and crank the engine over. You should see a bright blue spark jump the gap.

 

[Bill1987]

Re: Engine turns but won't start

i know how you feel. i have a 1978 webbcraft with a 305 Chevy inboard and a mercruiser 888 outboard. mine died one day while tubing and wouldn't start. after getting towed in it started right up. then it set parked for a couple of weeks before i had a chance to take it back out. now it wont start it tries to but wont. my mechanic told me it was hydra-locked to pull the plugs blow the water out by cracking it over. i did this and it worked. i ran it for approximately 30 min on the water hose. took it to the lake the next day and it started but ran for about 30 seconds then died and locked back up. so i have been working on it and have discovered the shafts in the lower unit turn together one way but not the other i am assuming there is something messed up there. does any one know the trick to pulling the shafts out i have it tore down just cant get them out. also will this cause my engine to lock up or do i have other issues there. any reply is appreciated.

 

[Don S]

Re: Engine turns but won't start

Welcome to iboats Bill1987.
You need to start a new thread of your own, and use the proper forum. You have a Mercruiser, and this is the Volvo forum.
Also read the "Announcement" at the top of this forum.

 

[Pete1burn]

Re: Engine turns but won't start

The neutral safety switch controls the use of the starter, nothing to do with the ignition at all. The switch that controls the ignition would be the safety kill switch (the one with the lanyard)
What is the FULL model number of your engine? That's all the other letters after the 4.3GS.

To check for spark, Remove the coil wire from the distributor cap, hold the wire about 1/2" from a good clean ground (NOT Paint) and crank the engine over. You should see a bright blue spark jump the gap.

Hey Don. I took one of the spark plugs out and grounded it to the engine mount and had a friend turn it over. I saw no spark. Wouldn't that mean the coil wire isn't getting juice either?

I also replaced the kill switch and tested the wires, which were fine. Another issue is the guy who had it before me spliced the yellow/red wires to brown, and there are a ton of brown wires under there.

I'd love to get the entire serial number, but the numbers on the sticker are non-existent.

Edit: This might be it: 4111506964

 

[Pete1burn]

Re: Engine turns but won't start

Searched through the SELOC manual and marked all the pages that have to do with my engine.

 

[Maclin]

Re: Engine turns but won't start

Have you checked the voltage at the + coil terminal 1.) with engine off key on, and 2.) while cranking?

 

[Pete1burn]

Re: Engine turns but won't start

Not yet. The boat is at my camp. Hoping to go up sometime next week and bring it back so I can work on it.

I'm thinking it has to be the kill switch. When the boat was dead in the water, my uncle took the killswitch off the gunnel and pulled it out to get to the wires. So my thought is, when I took the lanyard out for the first time, perhaps it broke the killswitch inside. Then when he pulled it out to get to the wires, he pulled one of them apart at a splice somewhere. That's the only thing I can think of since it worked perfectly fine before pulling out the lanyard.

Replacing it with a new killswitch like I did wouldn't matter in that case if the wire is disconnected further back.

Might be a long shot, but it's all I have to go on at this point, and it's feasible.

 

[Don S]

Re: Engine turns but won't start

Was just going over this again,

1. Changed wires to the back of one of the instrument panels for power to the stereo

Disconnect the stereo. That is not where you pickup power for accessories, and probably blew the fuse for your ignitions system.
Look under the helm for a purple wire with a fuse in it.
The ignition switch and instruments are part of the engine wiring, and NOT where you tap power for accessories.

Here is a link to the OEM manuals for the 94 MD models. http://www.4shared.com/dir/14518511/785d67cc/MDsharing.html
Has to be better than a Seloc, If you took a good running engine, and did everything exactly like seloc says, the chances are high that your engine wouldn't run.

I took one of the spark plugs out and grounded it to the engine mount and had a friend turn it over. I saw no spark.

Why don't you just check spark like I suggested, we want to see if you have spark from the coil, not just one spark plug.

 

[Pete1burn]

Re: Engine turns but won't start

Yeah I know I have to change the wiring for the stereo. The only reason I used it is because stereos need one lead with constant 12v and one lead for 12v power. That was the only lead I could find that had power when the key was on and not otherwise. I'll have to figure something else out for the stereo like a manual switch.

I had tested out the spark plug before your response and I was already back home when I saw it. I will certainly check the coil first thing when I get back to the boat.

 

[Pete1burn]

Re: Engine turns but won't start

Oh, and what does MD mean?

 

[benjh1028]

Re: Engine turns but won't start

Pete,

Sounds like the same thing that happened to me on my 1995 Larson LXi with a 5.0 Volvo, and it drove me nuts. Turned out to be a worn float needle in the fuel reservoir system which is the last stop for the gas before the fuel injectors. This seems to be a common issue that requires regular maintenance (like changing the impeller). The fuel was actually filling up the reservoir and venting into the oil. I bought the entire "Fuel Reservoir Sealing Kit" (which contains the needle and other parts) as it was only a few bucks more than the float needle by itself ($30). Took 20-min to fix and cranked right up.

The easy fixes are usually the toughest to diagnose.

Ben