Changed out impeller now boat won’t start

[Johnny Chavez]

Out in the water yesterday, launched the boat, slipped it, then loaded the fam and was headed out. Ran for about ten minutes then I got an alarm, looked down and I’m starting to overheat. Turned around and slipped it again then changed the impeller. By the time I got back into the slip the temp was almost at 240. After I changed the impeller the boat fired up, ran for about 3 seconds then died. Now it turns over but won’t fire. Truer starter fluid and nothing. Don’t think I’m getting any spark to the plugs. I’ve read about a cdi box that could be the problem if the capacitors overheated then that can prevent spark? I’ll try anything if any suggestions are made. It’s a VOLVO PENTA 8.1GI-J and yes, full tank of gas.

 

[StevieHops]

Make sure you didn’t hit the kill switch lol

 

[rickym20]

Is water making it to the impeller? Feel the water hoses going to the pump. If no water is making it to impeller , your pick up line can be clogged with something like sand or? I had ran through some sand at the mouth of the river on my last boat and boat got hot quick. It ended up being sand clogging up pick up line to the water pump. Once I cleared that it was all good.

Can’t speak to why it’s not starting now.

 

[Johnny Chavez]

Make sure you didn’t hit the kill switch lol

honestly, that wasn’t the first thing I checked but later on I did check it. I played around with the lanyard and made sure that was working. just weird that when I did change the impeller it fired up then died a few seconds later.

 

[Johnny Chavez]

Is water making it to the impeller? Feel the water hoses going to the pump. If no water is making it to impeller , your pick up line can be clogged with something like sand or? I had ran through some sand at the mouth of the river on my last boat and boat got hot quick. It ended up being sand clogging up pick up line to the water pump. Once I cleared that it was all good.

Can’t speak to why it’s not starting now.

yes, water is flowing. Just had the boat out two weeks ago too and ran like a champ. I’ve actually never had any problems with this boat or motor.

 

[RogerThat99]

Usually when the impeller goes, little chunks break off and plug some of the paths of the coolant, and the system needs to be back flushed to get the pieces out.

With that said, I don't know why it won't run.

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[Johnny Chavez]

Usually when the impeller goes, little chunks break off and plug some of the paths of the coolant, and the system needs to be back flushed to get the pieces out.

With that said, I don't know why it won't run.

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yea, I got what I think was all of the chunks out. I also believe that I’m passed the cooling system problem, just hoping the little fairies magically show up and get in there and fix the problem now so I can get back on the water lol

 

[Heylam]

Check the main harness where it plugs in at motor, possibly bumped it when changing impeller

 

[CobraDave]

Is it possible the impeller was installed in the wrong direction?


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[Johnny Chavez]

Check the main harness where it plugs in at motor, possibly bumped it when changing impeller

i has another guy with me and he checked all the plugs and harnesses.

 

[Johnny Chavez]

Is it possible the impeller was installed in the wrong direction?


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definitely installed the correct way. There are threads on one side and smooth on the other, I just put it the same way

 

[JUSTWANNARACE]

Power wire to the distributor?

Is there a main breaker for the power somewhere?

 

[Johnny Chavez]

Power wire to the distributor?

Is there a main breaker for the power somewhere?

no distributor on this motor, individual coil packs per spark plug

 

[Johnny Chavez]

no distributor on this motor, individual coil packs per spark plug

oh and yes, I’m the fuse box there is a main breaker. Check led continuity on that as well, all good.

 

[StevieHops]

Sounds like a fuel problem. Check out the fuel pump, they are Known for going out and they are not cheap. Pull off the high pressure side, if it doesn’t shoot out you found your problem.

 

[Shlbyntro]

Check to make sure you didn't bump the wire on the crank position sensor at the front of the motor while you were down there playing with impeller.


Also:
The volvo fuel pump assemblies rely on the cold water from your raw water pump to keep the fuel pumps cooled as well. There is a possibility that in the time to took you to get back to the slip, the fuel pumps may have been overheated and now dont want to play nice. I'd check to make sure you can hear each fuel pump run by unplugging them one at a time and cycling the key. If they both run, see if you have good fuel pressure up at the rail.

The fuse box assembly on top of these engines is known for having issues too especially after getting warm. As mentioned above do a wiggle test on top at every wire connection going in and out of it as well as the fuses and relays inside.

 

[Lavey 29]

its a crank mounted pump and see no way how this would effect a no start engine. I have changed at least 1000 of these Volvo penta crank mount mounted pumps and even completely pulled them off to fix the leaking seal and bad bearing internally and reinstalled the complete. prob done 500 of them as well.

Questions -- Did this engine run just before you pulled impeller ? Have you scanned the engine ? do you have fuel pressure ? Do u have spark ??

fuel pressure is tested right on the shrader valve on the fuel rail. Its there to do so. Spark is simple to test -- go buy 8 inline sealed spark testers and hook up. For people working on their boats --- the proper service manual and proper tools for testing and installs - plus the correct updated scan tool sure will help one fix the issues. Good info for all.

Next the heat could have shorted out something in the wiring harness ??? Also does your fuel pumps turn on with key on ? Next is HOW ABOUT THE SIDE of BREAKERS AND OR RELAYS and or fuses as heat possible killed them or one them ? Next is the ecm === high heat can generate resistance and or shorts and or voltage spikes back thru the harness and or the alternator into the ecm. ECM s can not tolerate any of that including high heat

 

[Johnny Chavez]

its a crank mounted pump and see no way how this would effect a no start engine. I have changed at least 1000 of these Volvo penta crank mount mounted pumps and even completely pulled them off to fix the leaking seal and bad bearing internally and reinstalled the complete. prob done 500 of them as well.

Questions -- Did this engine run just before you pulled impeller ? Have you scanned the engine ? do you have fuel pressure ? Do u have spark ??

fuel pressure is tested right on the shrader valve on the fuel rail. Its there to do so. Spark is simple to test -- go buy 8 inline sealed spark testers and hook up. For people working on their boats --- the proper service manual and proper tools for testing and installs - plus the correct updated scan tool sure will help one fix the issues. Good info for all.

Next the heat could have shorted out something in the wiring harness ??? Also does your fuel pumps turn on with key on ? Next is HOW ABOUT THE SIDE of BREAKERS AND OR RELAYS and or fuses as heat possible killed them or one them ? Next is the ecm === high heat can generate resistance and or shorts and or voltage spikes back thru the harness and or the alternator into the ecm. ECM s can not tolerate any of that including high heat

appreciate the response. It gave me an alley to go down. I’ve now checked and replaced all spark plugs (yes, good spark them). I’ve checked both pressure pumps. When I turn the key on the low pressure goes to 10psi and the highpressure goes to about 40psi. When cranking the engine the low pressure stays at 10 and the high pressured drops to about 35psi.

Yes, the boat was running then I changed the impeller. After that, I turned it on and it ran for about 3 seconds then died.

I’ve checked all fuses and the only breaker I have is a 40 amp breaker for the trim pump.

is there a way to check the ECM? Would the ECM still allow spark to the plugs if it got shorted? Also, when I turn the key on I don’t get an audible alarm anymore either, just cranks and won’t fire.Possibly electrical now?

 

[StevieHops]

Where are you located?

 

[Johnny Chavez]

Where are you located?

chino, ca

 

[Shlbyntro]

appreciate the response. It gave me an alley to go down. I’ve now checked and replaced all spark plugs (yes, good spark them). I’ve checked both pressure pumps. When I turn the key on the low pressure goes to 10psi and the highpressure goes to about 40psi. When cranking the engine the low pressure stays at 10 and the high pressured drops to about 35psi.

Yes, the boat was running then I changed the impeller. After that, I turned it on and it ran for about 3 seconds then died.

I’ve checked all fuses and the only breaker I have is a 40 amp breaker for the trim pump.

is there a way to check the ECM? Would the ECM still allow spark to the plugs if it got shorted? Also, when I turn the key on I don’t get an audible alarm anymore either, just cranks and won’t fire.Possibly electrical now?

Sounds like it. But you said good spark at the plugs.... you either have spark or your dont in this kind of scenario. Have you verified spark while cranking during this no start predicament? If you can find a noid light set, it would be worth checking out the injector pulse from the ecm.

Theres really only 3 ways to check the ecm: process of elimination, eliminate absolutely everything else. Swap it with another one from the same kind of engine and see if the problem goes away. Or, send the ecm out to Volvo and have it tested which will cost but is an easier pill to swallow than buying a new ecm that you didn't need.