3.9 starting problems

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Posts
24
Location
Mansfield
Hi all, new to the site and needing your thoughts on a subject, i may not get a very warm responce when i tell you its actually a speed boat ! Any way here goes , bought a boat with the 3.9 that didnt run, needed a new fuel pump, timing 180 out and plug leads any how. had it running off a remote fuel supply for about 15 seconds then turned it off as the exhaust pipes after the manifold are rubber and need cooling from water from the river, anyway it ran sweetly, a few months on after doing other work i tried to start it but it wouldnt have any of it. the plugs were wet, the injection is working but the plugs get wet , disconnect the fuel pump wires and turn the engine over about 8 times and it starts and runs with the fuel pressure in the system till it cuts out, wire in the pump, can hear the fuel return into the tank , cranks over but no start, disconnect and after a few turns it starts again ! any ideas chaps. thanks
 
Hi all, new to the site and needing your thoughts on a subject, i may not get a very warm responce when i tell you its actually a speed boat ! Any way here goes , bought a boat with the 3.9 that didnt run, needed a new fuel pump, timing 180 out and plug leads any how. had it running off a remote fuel supply for about 15 seconds then turned it off as the exhaust pipes after the manifold are rubber and need cooling from water from the river, anyway it ran sweetly, a few months on after doing other work i tried to start it but it wouldnt have any of it. the plugs were wet, the injection is working but the plugs get wet , disconnect the fuel pump wires and turn the engine over about 8 times and it starts and runs with the fuel pressure in the system till it cuts out, wire in the pump, can hear the fuel return into the tank , cranks over but no start, disconnect and after a few turns it starts again ! any ideas chaps. thanks
Welcome to LZ!

Certainly not a problem, we like boats!

A bit more detail would be helpful.

Assuming this is a 3.9 fuel injected petrol engine from a Discovery 2 or Range Rover?

Has the engine been marinised in any way? If so, do you know by who?
Your post seems to indicate raw water cooling e.g water from body of water in which the boat is floating pumped round the engine to cool it.
If this the case, or do you have keel cooling, or a radiator, and a separate system that cools the exhaust?

As this may well be a one off installation, pictures would be very helpful, as well as of general interest.
 
Welcome to LZ!

Certainly not a problem, we like boats!

A bit more detail would be helpful.

Assuming this is a 3.9 fuel injected petrol engine from a Discovery 2 or Range Rover?

Has the engine been marinised in any way? If so, do you know by who?
Your post seems to indicate raw water cooling e.g water from body of water in which the boat is floating pumped round the engine to cool it.
If this the case, or do you have keel cooling, or a radiator, and a separate system that cools the exhaust?

As this may well be a one off installation, pictures would be very helpful, as well as of general interest.
Hi Turboman,
Yes to the engine though im sorry i dont know from what vehicle, its got the 14CUX but from my research its the older type of loom without fuses, i have fitted two myself though !
The engine is fully marinised, with proper water cooled exhaust manifolds, raw water pump and velvet drive gear box, i didnt like the thought of river water in the ally engine so have fitted a closed cooling system with a heat exchanger that is cooled from the raw water before exiting the exhausts. i have had noid lites on the injection plugs and all flash, for some reason when the pump is energised and working the engine will not fire at all, the plugs get wet but no bang bang, disconnect the pump, spin it over a few times and it fires up and ticks over smoothly, on with the pump and no go again ! tried tonight with a separate feed from the battery to the pump incase of a wiring issue upsetting the ECU but just the same, must be a simple answer to it, the censer on the rail maybe ??
 
Hi Turboman,
Yes to the engine though im sorry i dont know from what vehicle, its got the 14CUX but from my research its the older type of loom without fuses, i have fitted two myself though !
The engine is fully marinised, with proper water cooled exhaust manifolds, raw water pump and velvet drive gear box, i didnt like the thought of river water in the ally engine so have fitted a closed cooling system with a heat exchanger that is cooled from the raw water before exiting the exhausts. i have had noid lites on the injection plugs and all flash, for some reason when the pump is energised and working the engine will not fire at all, the plugs get wet but no bang bang, disconnect the pump, spin it over a few times and it fires up and ticks over smoothly, on with the pump and no go again ! tried tonight with a separate feed from the battery to the pump incase of a wiring issue upsetting the ECU but just the same, must be a simple answer to it, the censer on the rail maybe ??
Good move with the keel cooling, I don't like raw water cooling much on any engine.

Do you have tin square relays, and are they working?

And likewise crank sensor?

I think you might be best to post about this in the Disco Section, as I think it likely that engine will have come out of a Disco. Link below.

https://www.landyzone.co.uk/forum/land-rover-discovery.8/
 
Hello and welcome :)
sounds interesting:)
could it be a power issue as when the pump is on its not leaving much for the sparks, check for corrosion on the connectors.
 
Good move with the keel cooling, I don't like raw water cooling much on any engine.

Do you have tin square relays, and are they working?

And likewise crank sensor?

I think you might be best to post about this in the Disco Section, as I think it likely that engine will have come out of a Disco. Link below.

https://www.landyzone.co.uk/forum/land-rover-discovery.8/
Hi again , both relays are fine , the pump cuts in and injectors fire as for the crank sensor it hasnt one , the negative on the coil tells the ECU instructions, The other gentleman asked about condition of connectors , all have been cleaned and in good condition, took a plug lead off and fitted a test plug and the arc is bright while turning over .
 
Hi again , both relays are fine , the pump cuts in and injectors fire as for the crank sensor it hasnt one , the negative on the coil tells the ECU instructions, The other gentleman asked about condition of connectors , all have been cleaned and in good condition, took a plug lead off and fitted a test plug and the arc is bright while turning over .
Post in the Disco section. I had a V8 Disco, but it was about 10 years ago, and surprisingly, not much went wrong with it when I had it.

The Disco boys and girls are on it all the time.
 
Welcome to the forum
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