Isuzu 25 starting problems

[john4647]

Can anyone help?

Isuzu 25 in a 4 yr old Liverpool Boat.

Does not want to start when hot. Turns over fine but will not fire. Serviced about 100 hrs ago, new fuel filters etc.

Previously well behaved. No apparent fuel leaks. Can only manage to start it by cranking the throttle wide open, then only starts under protest. A little black smoke at this point.

Once started, runs fine at speed and ticks over o/k.

Currently on the Thames, so we are a little concerned that the problem will develop. Any advice thankfully received.

 

John

[Smelly]

Can anyone help?

Isuzu 25 in a 4 yr old Liverpool Boat.

Does not want to start when hot. Turns over fine but will not fire. Serviced about 100 hrs ago, new fuel filters etc.

Previously well behaved. No apparent fuel leaks. Can only manage to start it by cranking the throttle wide open, then only starts under protest. A little black smoke at this point.

Once started, runs fine at speed and ticks over o/k.

Currently on the Thames, so we are a little concerned that the problem will develop. Any advice thankfully received.

 

John

 

Start it when it's cold. Get off the river. Tell us whether there's diesel at the injector unions when it's hot.

 

Saw a similar problem on a Perkins 4.108 a few years back; it was a leaky lift pump diaghram sucking air in but that was cam driven. On an Isuzu, if it's owt like our 35, it'll be electric, but still, checking there's fuel from the injector pump to the injectors will be a start.

[john4647]

Start it when it's cold. Get off the river. Tell us whether there's diesel at the injector unions when it's hot.

 

Saw a similar problem on a Perkins 4.108 a few years back; it was a leaky lift pump diaghram sucking air in but that was cam driven. On an Isuzu, if it's owt like our 35, it'll be electric, but still, checking there's fuel from the injector pump to the injectors will be a start.

Thanks for your reply.

Did you mean fuel at the injectors when cranking or when static.

It is an electric pump like the 35, also has an 'energise to run' solenoid.

[john4647]

No fuel at injectors with ign switched on.

Fuel at injectors (eventually) when cranking.

 

River canal rescue came out yesterday but were unable to find the problem (probably air leak, let it develop)

 

It did develop today en route to Lechlade (upper Thames) when the boat failed to proceed. Stopped for an hour then restarted, turned round and took refuge on the Oxford.

 

2nd RCR man came and although unable to be specific, bled the diesel system and sent us on our way. Hopefully might be o/k now but sadly SWMBO does not want to do rivers again.

 

Thanks for your input.

[Chalky]

Blindly obvious, but have you checked for diesel bug? My Isuzu 33 (in a 40' Liverpool - misbuild!) wouldn't restart when hot and it was contamination in the fuel filter. RCR should have found it, but its worth a check.

 

As an aside I had a similar problem on a tuned MG metro (many years ago) that would start when cold, cut out when hot and not restart until cool. Was caused by a blown head gasket.

[john4647]

Blindly obvious, but have you checked for diesel bug? My Isuzu 33 (in a 40' Liverpool - misbuild!) wouldn't restart when hot and it was contamination in the fuel filter. RCR should have found it, but its worth a check.

 

As an aside I had a similar problem on a tuned MG metro (many years ago) that would start when cold, cut out when hot and not restart until cool. Was caused by a blown head gasket.

Probably obvious to all but me but how do you check for diesel bug?

[bottle]

Look at your filters, if you have a slimy gunge you have the bug but RCR would/should have found it, if you had it.

 

Slightly different scenario, my friends boat would run for twenty minutes and then not accelerate, the problem was a hair line crack in the filter housing was a devil to find.

 

Clutching at straws, check the pipe runs is one a bit close to a heat source, could be causing an air lock.

Edited July 14, 2011 by bottle

[john4647]

Look at your filters, if you have a slimy gunge you have the bug but RCR would/should have found it, if you had it.

 

Slightly different scenario, my friends boat would run for twenty minutes and then not accelerate, the problem was a hair line crack in the filter housing was a devil to find.

 

Clutching at straws, check the pipe runs is one a bit close to a heat source, could be causing an air lock.

Both fuel filters removed and checked by RCR, no residue, perfectly clean. Can't see any cracks etc. (no leaks either).

Fuel pipes are where they have been for the last 1500 hrs so I assume they are o/k.

Will see how we go today.

John

[mrsmelly]

(in a 40' Liverpool - misbuild!)

 

arnt ALL Liverpool boats misbuilds ?

[WJM]

A bit of a long shot but... could your fuel tank breather be blocked? Try running with the fuel cap open?

 

I have a motorbike that suffers from fuel starvation due to a partial vacuum developing in the tank. It is probably less likely on a boat but its worth a shot.

[Chalky]

arnt ALL Liverpool boats misbuilds ?

This one was a classic. The boat arrived later than promised since they had problems sourcing a 25hp engine. When delivered it had a 33 fitted with an extra alternator, better gearbox & instruments. With the extra torque it only does about 900 rpm at canal speeds and means that the fuel consumption is rediculously low - 0.75 litre per hour cruising or charging.

[john4647]

A bit of a long shot but... could your fuel tank breather be blocked? Try running with the fuel cap open?

 

I have a motorbike that suffers from fuel starvation due to a partial vacuum developing in the tank. It is probably less likely on a boat but its worth a shot.

In a previous life in the motor trade this was a common Rover 3.5 fault. (Which I had forgotten about)

However now checked and it is clear.

Now waiting for a third visit from RRC having broken down 5+ hours ago.

John

[john4647]

Update,if anyone is interested.

RCR attended yesterday and decided it could be the stop solenoid (energise to run).

This was removed and I was instructed how to manually stop the engine.

Sadly, oil was pumped out of the hole in the diesel pump where the stop solenoid had been, resulting in no engine oil and a warning light for no oil pressure. Prior to this the engined had spluttered a couple of times anyway.

RCR attended again today, refilled with oil and refitted original stop solenoid, also replaced fuel pump.

Too late to go anywhere today so will try out tomorrow.

 

John