BMC 1.5 starting issues - urgent!

[ghostlymoron]

My pals boat had a BMC 1.5, it was always a pig to start. He eventually fitted a Thermostart which helped but was a bit scary.

 

[Heckler]

I agree that it seems very unlikely. The only reason I have suggested it is that I have started dozens of petrol/diesel/2T/4T engines with fuelling problems over the years using a squirt of fuel directly into the air intake, often using a hairdryer, and the engine nearly always starts ..... if only for a quick frenetic burst.

If the engine is petrol and there is no frenetic burst then I know it's probably an ignition problem. If the engine is diesel and there's no burst...... then what?

Richard

I am confused. If he has sprayed WD40 directly in to the intake then it should have fired irrespective of whether the injection system is working. Reading his posts, his knowledge of diesels is not that good, we are not able to see the big picture and so there are other things to take in to account. Is it cranking fast enough for example? etc etc.
Stu

Stu

 

[NormanB]

I think you may be on a hiding to nothing. You are finding all the evidence of a neglected and dirty fuel system and while you are doing all the right things - you are hoping the elephant in the room is not there. I reckon your fuel tank is 'leaping' and this will need to be addressed somehow, otherwise you are going to get through a gazillion filters and be cleaning gauze strainers up the ying yang and will still have an unreliable engine in the sense that it will let you down at the most inconvenient time.

Sorry for being so negative. I wish you luck in resolving the fuel system issues.

 

[Captn Black]

As mentioned before, the fuel tank was cleaned. But I have decided to start from the beginning again. Fuel filters taken apart and put back together, there was a twist in the main filter upper seal. Inspected the tank again, few black spots in there, must gave come back in to the tank from somewhere as it was clean. Both fuel filters only a week old and were changed after I cleaned everything.
The flexible return line from the head of the main filter to the tank was very brittle and cracked when I removed it, and although I noticed no fuel in the area, there could have been a crack there.
The lift pump seemed to have some air in the upper half as not much fuel came out when I removed the cap relative to the volume. I'm replacing the worn rubber seal with an aluminium one from the old lift pump I found onboard.

 

[ghostlymoron]

"reckon your fuel tank is 'leaping' and this will need to be addressed somehow,"
I've not encountered this term before do you mean leaking?

 

[Captn Black]

The lift pump takes 20 seconds to fill completely after the first few pumps, I don't know if this is normal, but the gauze is spotless. Perhaps the two little valves inside are sticking?
The starter battery is in great condition, and settles at 12.76v.
Bleeding the main filter now, so hopefully will be able to try starting her again in a few hours, after the rest is bled too.

 

[NormanB]

"reckon your fuel tank is 'leaping' and this will need to be addressed somehow,"
I've not encountered this term before do you mean leaking?

Sorry slang for filthy - like his socks were so dirty they were leaping around on their own.

 

[NormanB]

As mentioned before, the fuel tank was cleaned. But I have decided to start from the beginning again. Fuel filters taken apart and put back together, there was a twist in the main filter upper seal. Inspected the tank again, few black spots in there, must gave come back in to the tank from somewhere as it was clean. Both fuel filters only a week old and were changed after I cleaned everything.
The flexible return line from the head of the main filter to the tank was very brittle and cracked when I removed it, and although I noticed no fuel in the area, there could have been a crack there.
The lift pump seemed to have some air in the upper half as not much fuel came out when I removed the cap relative to the volume. I'm replacing the worn rubber seal with an aluminium one from the old lift pump I found onboard.

Sorry I missed that first time around. My bad.
You are doing all the right things and it sounds like you could also be drawing in air on the lift pump suction lines.

 

[Captn Black]

Thanks Norman, I'll look into that now.

 

[Captn Black]

Oh, and I should mention that the wd40 can is only 1/4 full, so it may not have enough output to induce a firing if, as it seems, there is almost no fuel flow.

 

[ffiill]

Hate to be the tidings of bad news.
I left my Mercedes OMC636 from Autumn 2015 until January 2017 whilst boat was ashore.
This engine has reliably started and run over the past 12 years.
Similarly just a dribble out of the injector pipes.
I cleaned the filters etc and persuaded engine to run briefly.
There was a lot of fine black dirt in the filter so I took the bull by the horns accessed the tank top where luckily I found a nice sized inspection hatch.
Two weeks ago I emptied the 40 gallon tank using a hand cranked transfer pump.
The tank is lined with a black goo and when I examined the fuel whilst it appeared clean it was almost opaque when I put it in a glass and compared it to fresh fuel.
Diesel Bug!!
My next task is to clean the tank with water and detergent using various angled nozzles made up from 10mm and 15 mm copper pipe.
Then its fill it up with water and a very good measure of bleach:drain it and let it dry off before refilling.
Then there is tank number two.
Looks like its another summer ashore unlike some years ago when the boat was permamently afloat.
Best of luck

 

[Captn Black]

Yea, I'm not fooling myself that the diesel bug issue is solved, but due to the circumstances I just need her to run for a few hours. Once I'm moored at the new anchorage I'll clean everything again, and use bug treatment with new fuel and filters.

 

[Captn Black]

UPDATE - Hard to narrow down which thing helped, but am now up to 12-15 drops of fuel from hp lines after 8-10 seconds cranking. Still won't start, but the battery will need more juice now as it was needed for final bleeding stage.
Need to find virgin to sacrifice to Poseidon

 

[Deleted member 36384]

I had an impossible starting issue with this engine at sea. I traced the fault to the non return valve in the lift pump. I discovered this by blowing through each end with just my breath. The air was stopped each way. The ball that makes the seal was is held open by a spring, the spring had rusted and broken up allowing the ball to seat both ways. I replaced the spring from a Biro pen and it worked, engine started.

Apologies if this is errelecant but I have just read a few posts in the thread. On a phone with a small screen and travelling.

Good luck.

 

[Captn Black]

I had an impossible starting issue with this engine at sea. I traced the fault to the non return valve in the lift pump. I discovered this by blowing through each end with just my breath. The air was stopped each way. The ball that makes the seal was is held open by a spring, the spring had rusted and broken up allowing the ball to seat both ways. I replaced the spring from a Biro pen and it worked, engine started.

Apologies if this is errelecant but I have just read a few posts in the thread. On a phone with a small screen and travelling.

Good luck.

I did exactly the same thing, as you see if you check my original post. I even found old bits of the spring inside the injector union today, sobut don't forget to have a look there!

 

[RichardS]

Oh, and I should mention that the wd40 can is only 1/4 full, so it may not have enough output to induce a firing if, as it seems, there is almost no fuel flow.

As Stu says above, it's actually the WD40 when sprayed into the air intake which is combusting rather than the diesel. The hoped for result of this is that, once the engine fires on the WD40, the fuel pump etc will spring into life and start to inject diesel and the diesel will then take over combustion duties from the WD40.

It therefore doesn't matter how much WD40 is left in the can provided that the can is held right-way-up so that you get a good spray going you should hear the engine firing even if it only lasts a couple strokes because the diesel is not there to "take over". If the engine even fires only once you will hear it as it's a completely different sound to cranking.

I remain confused as to why the WD40 is failing to do anything.

Richard

 

[clyst]

Thanks for replies. The seacock was shut during the 10 months, but open now.

Glow plugs drawing power when activated, though they aren't needed here.

Every single line individually removed and cleaned. A good squirt of fuel comes through at all stages of bleeding, and through all lines, except the high pressure lines.

So, the injector gause? Anything to watch out for when I start that job?

Please shut the sea cock whilst you are cranking your engine to save drawing water into the engine .

 

[clyst]

Why not just take the lift pump suction of clean fuel from a "gallon can " ? ......... Can't explain why WD 40 doesn't work sprayed in to the air intake though ......you taking the air filter off I presume .

 

[Deleted member 36384]

I did exactly the same thing, as you see if you check my original post. I even found old bits of the spring inside the injector union today, sobut don't forget to have a look there!

Okay but I am not talking about the main filter, I am talking about the lift pump, on the engine there is a ball type non return valve inside the lift pump. My experience has nothing to do with filters, only the lift pump.

 

[<152587>]

I realise you are probably in stress mode at the moment but we cannot help you if you do not listen. Firstly, indirect injection engines do benefit from heater plugs whatever the climate. The fact you are spraying wd in the inlet track and still no combustion suggestx lack of compression or the engine is sluggish to crank. Use heater plugs then crank while introducing wd into the tract. If you have have sufficient cranking speed on the motor to achieve the necessary compression it WILL fire.