Can you help 15BFT

[Gengis]

You dont want to go down this rabbit hole, we have some members with some rather strong points of view on this, both ways.
I would say, make sure that you have no leaks or blockages and that the cut off on the IP is functioning, then if the problem persists, fit a lift pump. If this solves the problem, then you may have a weak IP fuel pump.

 

[PIeman]

Thank you

 

[roscoFJ73]

what would be the downside of fitting an electric lifter in the line before the filter and primer. If the primer is leaking the positive pressure would make this obvious if its the lifter mounted on the standard linear pump that is at fault will an additional pump help it or hinder? My primer is a cylindrical one that mounts on top of the filter I think it can be blocked and the electric lifter pump used to bleed the system. Thanks for the facebook link

If you bypass the primer pump, you will bypass the fuel filter.
(and on the fuel filter topic, they are often a source of air leaks as well. remove and refit.)


The other question that springs to mind is why the primer is worn out in the first place. Often its because the owner, in the mistaken belief he needs to pump furiously to get air out, only to find the air has leaked back in from somewhere while he is walking to the ignition key. If the problem is sorted, the primer only needs to be used when changing a filter once or twice a year.
Toyota designed these fuel systems to be simple and able to be fixed in the field.

 

[PIeman]

thank you

 

[myusername]

The other question that springs to mind is why the primer is worn out in the first place. Often its because the owner, in the mistaken belief he needs to pump furiously to get air out, only to find the air has leaked back in from somewhere while he is walking to the ignition key. If the problem is sorted, the primer only needs to be used when changing a filter once or twice a year.
Toyota designed these fuel systems to be simple and able to be fixed in the field.

The old primers often leak when they've sat. You unscrew them, pump, and they leak fuel everywhere, then when you shut them they no longer seal and are a source of an air leak. 2/3 I've used leaked... including the one on my 15BFT.

The Coaster 15BFT primer is on the top of the fuel filter housing at the front of the engine. It's not the same as the usual one on the fuel feed/lift pump, it has a larger thread. I couldn't find an aftermarket one the right size and could only find 1 supplier that stocked them. It appears the usual style may fit on the lift/feed pump but the fuel return line or something is in the way. I assume they put it on top to be accessible by a service hatch when the engine is installed in a bus?

Some good suggestions on here - clamp and remove fuel feed and return lines, run from a fresh raised fuel supply, replace fuel filter, check primer doesn't leak, check fuel inlet banjo screen/filter, remove vac line from shut down, if it still doesn't want to stay running it needs to go to a specialised diesel mech to get a compression test and then an expensive injection pump repair...

 

[roscoFJ73]

The old primers often leak when they've sat. You unscrew them, pump, and they leak fuel everywhere, then when you shut them they no longer seal and are a source of an air leak. 2/3 I've used leaked... including the one on my 15BFT.

The Coaster 15BFT primer is on the top of the fuel filter housing at the front of the engine. It's not the same as the usual one on the fuel feed/lift pump, it has a larger thread. I couldn't find an aftermarket one the right size and could only find 1 supplier that stocked them. It appears the usual style may fit on the lift/feed pump but the fuel return line or something is in the way. I assume they put it on top to be accessible by a service hatch when the engine is installed in a bus?

Ive had 3 landcruisers with this type of filter. Its pretty much the same on all Toyota buses, trucks , utes and any other diesel after around 1990. There is no return line back to the filter, they all go back to the tank to cool the fuel.

 

[roscoFJ73]

Some good suggestions on here - clamp and remove fuel feed and return lines, run from a fresh raised fuel supply, replace fuel filter, check primer doesn't leak, check fuel inlet banjo screen/filter, remove vac line from shut down, if it still doesn't want to stay running it needs to go to a specialised diesel mech to get a compression test and then an expensive injection pump repair...

I dont see why an engine would need a compression test because it wont start or keep running. If it was that bad it would be smoking like a steam train and you wouldnt bother with a compression test for its next life as a boat anchor.
And you can do it yourself, its easy, you dont need a specialised diesel mechanic. I sincerely doubt it needs "expensive internal injection pump repair"
Its either an electrical fuel cut off or an air problem.
Buts its also a time problem. You need to spend lots of time isolating the problem and checking the components of the fuel supply. Thats all you would be paying a diesel mechanic to do at $100 an hour.

 

[myusername]

There is no return line back to the filter, they all go back to the tank to cool the fuel.

I think you misread: "It appears the usual style may fit on the lift/feed pump but the fuel return line or something is in the way"

I have a 15BFT from a Coaster. The primer is on the fuel filter which is mounted on the front of the intake manifold, in that regard it's not quite the same as the usual landcruiser filter housing. It is similar to, but not the same as the usual landcruiser primer, trust me I tried to swap the usual bosch replacement on and found it didn't fit - had to order a genuine one. I assume a larger primer is required due to the placement. The only other place I've seen a primer located up on the filter housing was on an imported BJ from NZ, presumably originally from Japan which was fitted with a rotary injection pump (would not have the lift/feed pump where the primer is usually located).

On the Coaster 15BFT the fuel return line is in the space above the fuel feed/lift pump (where the primer is on a B/3B/2H/12HT etc etc), I haven't checked to see if I can simply install a primer here (although I had a peek and it looks like it might work), nor did I confirm if it's possible to simply rotate the fuel return line to create enough room. Mainly because ordering a new primer was the easiest way to plug my leak and provide a primer - two birds one stone.

If you don't believe me about them leaking, I'm happy to unscrew the primer and video the fuel that runs out before it's even pumped...

 

[myusername]

I dont see why an engine would need a compression test because it wont start or keep running. If it was that bad it would be smoking like a steam train and you wouldnt bother with a compression test for its next life as a boat anchor.
And you can do it yourself, its easy, you dont need a specialised diesel mechanic. I sincerely doubt it needs "expensive internal injection pump repair"
Its either an electrical fuel cut off or an air problem.
Buts its also a time problem. You need to spend lots of time isolating the problem and checking the components of the fuel supply. Thats all you would be paying a diesel mechanic to do at $100 an hour.

If it won't start or keep running with the simple things ruled out: a new filter, fresh fuel supply, and the injection pump in the run position by removing the vacuum line to the shutoff... it's potentially an expensive repair. It doesn't take long to chase the fuel supply if you replace the filter and primer and run it out of jerry to bypass the lines and tank etc.

Sometimes spinning them over eventually gets enough fuel in that a diesel will fire for a few rotations and then die as soon as they spin up and creates enough low suction in the fuel system to suck air in the fuel. A puff of smoke on startup is normal with these, so if it's struggling to start and not running for long at all he won't have much of an indication to go by.

Compression check is the simplest way to get an impression of the overall health of the engine. With no glow plugs (15BFT is direct injection), you have to pull the injectors, which isn't really something you should encourage a totally inexperienced mechanic to do themselves to an expensive diesel engine.

If it has compression but won't keep running, fingers get pointed at the injection pump. Any injection pump repair is expensive, especially when it's a comparatively rare pump that tech's aren't familiar with.

 

[roscoFJ73]

We havent seen what the others are using for filters/primers. I asked for pics and they were not forthcoming. It was my understanding they had different filtration to what you are showing.

 

[myusername]

15BF and 15BFTE vary a bit between what application they are from - different sumps, different ancillary layouts, etc

I think 15BFT with inline pump were only fitted to coasters. 15BT in a Megacruiser is different.

 

[PIeman]

Hi there, I'm new to this site and not very mechanically minded and I'm looking for some advice from anybody that can help. I have a 1999 Ceatano optimo 4 bus with a 15BFT engine. The engine cut out recently as if out of fuel, the engine will restart and run for a few seconds and then just fades again. I have had 2 mechanics look at it but without success. Does anybody have any ideas please. P.S. it had plenty of fuel.

Hi Milo
I found a bosch primer online not sure if it will fit but at less than £10 it's worth a punt. Should turn up this week I will advise if it fits. It would be a good starting point and well within the capabilities of any DIYer

 

[myusername]

Hi Milo
I found a bosch primer online not sure if it will fit but at less than £10 it's worth a punt. Should turn up this week I will advise if it fits. It would be a good starting point and well within the capabilities of any DIYer

Read my reply above, the usual Bosch primer pump that Landcruiser owners recommend goes on the fuel feed pump attached to the injector pump. The primer which goes on the fuel filter housing on a Coaster 15BFT is physically larger and has a larger thread. I already tried.

 

[myusername]

“The usual” Bosch primer vs the 15BFT primer. Have taken a pic next to a 3B injector pump and next to a 15BFT for comparison.

NB: there are many versions (and many fakes) of this Bosch unit, made in different countries from different materials etc.

 

[PIeman]

Read my reply above, the usual Bosch primer pump that Landcruiser owners recommend goes on the fuel feed pump attached to the injector pump. The primer which goes on the fuel filter housing on a Coaster 15BFT is physically larger and has a larger thread. I already tried.

This one comes with an adapter ring which although may not work looks fairly close, will advise later in the week

 

[Squash]

You should crack the bleeder screw, then pump the primer, once fuel is clear push primers down and screw in to lock and then tighten bleeder.
Many people try forcing the primer down but never actually lock in position.
Conversely if your unit is in good shape your primer will be hard to pump almost instantly, so crack the bleeder and then tighten.
Yes the top may leak but once tightened it should be good.
We've run hundreds of diesels in mining and I've had my share of leaking primers, once locked they normally offered a good days work.

 

[myusername]

You should crack the bleeder screw, then pump the primer, once fuel is clear push primers down and screw in to lock and then tighten bleeder.
Many people try forcing the primer down but never actually lock in position.
Conversely if your unit is in good shape your primer will be hard to pump almost instantly, so crack the bleeder and then tighten.
Yes the top may leak but once tightened it should be good.
We've run hundreds of diesels in mining and I've had my share of leaking primers, once locked they normally offered a good days work.

Mine leaked fuel all over the intake as soon as it was unscrewed, pumping it just sprayed fuel everywhere. Got engine running and it was leaking at the primer. Old rubber and fuel

 

[Squash]

Ah yes!
But it still ran and that's the beauty of the system. Pretty common part on underground mining equipment.
Used to sometimes piss me off that I'd have to prime a $1000,000.00 unit everyday until it was scheduled for service.

 

[PIeman]

Are you making any progress Milo?

 

[myusername]

Are you making any progress Milo?

OP's usually silently disappear when their issue is sorted