Smiling Ben
New Member
Looks like I will be finding an injector specialist in South Wales. Any suggestions?
Thornycroft 90
- Thread starter Smiling Ben
- Start date
DownWest
Well-Known Member
Any road diesel injector outfit will check injectors out for not a lot of money. Just ask your local garage, or the yellow pages. The pump is slightly more tricky and a bit old, so almost certainly will need bits to rebuild. I had one done for a 4-108 after it started leaking fuel into the sump. They had some used spares and gave me a friendly price, as I was giving them bigger business for clients.
Boater Sam
Well-Known Member
If its spinning over quicker and
not firing, it could well have lost compression.
In which case
it will never run properly till its been overhauled.
not firing, it could well have lost compression.
In which case
it will never run properly till its been overhauled.
easton
Member
There is a diesel place at Cardiff Marina, they were a bit pricey if I recall but did a good job. It is quite an old engine, so as DownWest says, anywhere that does road diesels should be able to tackle it. They were extensively used on old tractors and also on canal boats, so look out for a decent place next to a canal!
There are a few places online too but I've never tried them. I'd get the seals changed so it's good for modern diesels with biofuels, it's cheap insurance. Seals, governor blead screw and calibration, check the entire fuel system for cleanliness and leaks. Is the tank clean?
I'm pretty sure it's a Lucas DPA pump (3246857) with Hydraulic Governor (I'm sure you know it's a BMC 1.5 engine) but there will be a plate on the side of the pump that tells you precisely what it is.
(if it's spinning over quickly it may be because one or two cylinders are firing but the engine just isn't firing on all four enough to sustain itself).
Andrew
There are a few places online too but I've never tried them. I'd get the seals changed so it's good for modern diesels with biofuels, it's cheap insurance. Seals, governor blead screw and calibration, check the entire fuel system for cleanliness and leaks. Is the tank clean?
I'm pretty sure it's a Lucas DPA pump (3246857) with Hydraulic Governor (I'm sure you know it's a BMC 1.5 engine) but there will be a plate on the side of the pump that tells you precisely what it is.
(if it's spinning over quickly it may be because one or two cylinders are firing but the engine just isn't firing on all four enough to sustain itself).
Andrew
Smiling Ben
New Member
UPDATE!!
After a couple of weeks of stressfully attempting to get the original fuel pump and original injectors serviced; I have now purchased and fitted reconditioned injectors and a reconditioned BMC 1.5 fuel pump.
I have rigged up an auxiliary Jerry can with clean diesel into the lift pump, and have the return pipe from the secondary filter going into the Jerry can too. So, I am sure that I am only handling clean fuel.
The engine still turns over way too fast in my opinion, and takes upto 30 seconds to fire. Once running, it sounds excellent.
It runs for about 5 minutes and then cuts out, quickly.
Exhaust fumes are not visible. A small plume of blue smoke has been observed escaping from the air inlet on the engine.
I havent been able to observe her temperature gauge prior to cut out, busy elsewhere on every occasion. Once cut out, the engine doesn't feel unduly hot. Warm, but not roasting.
Once it has cut out, I have to wait until it has cooled completely before it will start again.
Another berth holder who very kindly showed interest and spent a couple of hours imparting some excellent advice and wisdom, has suggested a number of things, based on the conclusion that when it warms up, some expansion occurs, which causes it to cut out.
- I need to check and adjust the spacings on the rockers.
- I need to check and adjust the timings of the valves.
- I need to commission an engineer to check the compression
- I might need to have the piston linings 'reconditioned' ?
What else??!!!!??
After a couple of weeks of stressfully attempting to get the original fuel pump and original injectors serviced; I have now purchased and fitted reconditioned injectors and a reconditioned BMC 1.5 fuel pump.
I have rigged up an auxiliary Jerry can with clean diesel into the lift pump, and have the return pipe from the secondary filter going into the Jerry can too. So, I am sure that I am only handling clean fuel.
The engine still turns over way too fast in my opinion, and takes upto 30 seconds to fire. Once running, it sounds excellent.
It runs for about 5 minutes and then cuts out, quickly.
Exhaust fumes are not visible. A small plume of blue smoke has been observed escaping from the air inlet on the engine.
I havent been able to observe her temperature gauge prior to cut out, busy elsewhere on every occasion. Once cut out, the engine doesn't feel unduly hot. Warm, but not roasting.
Once it has cut out, I have to wait until it has cooled completely before it will start again.
Another berth holder who very kindly showed interest and spent a couple of hours imparting some excellent advice and wisdom, has suggested a number of things, based on the conclusion that when it warms up, some expansion occurs, which causes it to cut out.
- I need to check and adjust the spacings on the rockers.
- I need to check and adjust the timings of the valves.
- I need to commission an engineer to check the compression
- I might need to have the piston linings 'reconditioned' ?
What else??!!!!??
Boater Sam
Well-Known Member
You have a lack of compression.
Causes, incorrect rocker clearances, or leaking valves or worn piston rings/bores. That is why it spins over too quickly and is reluctant to start.
So,
Set the rocker clearances, 15 thou I think, rule of 9, set #1 with #8 depressed, #2 with #7 depressed etc.
Get it compression tested. If still low, investigate the sealing of the valves and the condition of the bore wear ridge at the top of the cylinders by taking the cylinder head off. There are no liners.
Check the timing of the injection pump, not the valves.
Causes, incorrect rocker clearances, or leaking valves or worn piston rings/bores. That is why it spins over too quickly and is reluctant to start.
So,
Set the rocker clearances, 15 thou I think, rule of 9, set #1 with #8 depressed, #2 with #7 depressed etc.
Get it compression tested. If still low, investigate the sealing of the valves and the condition of the bore wear ridge at the top of the cylinders by taking the cylinder head off. There are no liners.
Check the timing of the injection pump, not the valves.
Minerva
Well-Known Member
I bled out t90 at the start of the season - I tied a bit of 3mm rope to the lift pump handle, up through a wee turning block I lashed to the roof of the engine bay and used that to pump the engine. Worked really well and saved lying on the engine to pump...
SlowlyButSurely
Well-Known Member
The engine may well have low compression but I have known engines that took way longer than 30 seconds cranking to start, but once running they stayed running.
This sounds more like a fuel problem to me. Your description sounds exactly the same as when I inadvertently turned off the fuel tap on my engine while it was running. Have you checked the lift pump and low pressure fuel pipes? And the stop control?
This sounds more like a fuel problem to me. Your description sounds exactly the same as when I inadvertently turned off the fuel tap on my engine while it was running. Have you checked the lift pump and low pressure fuel pipes? And the stop control?
PetiteFleur
Well-Known Member
I also had persistent air leaks before I re-engined. It had a CAV fuel filter, eventually removed it and stripped it on the bench. It had TWO rubber sealing rings in the top housing!! Eventually removed them, cleaned up the groove and fitted a new seal which solved that problem.
CAPTAIN FANTASTIC
Well-Known Member
Most certainly it is a fuel issue. The mechanical fuel lift pumps are not very reliable and they cost very little (~£20) to buy new, it is worth replacing the pump for a new one. You may be better off getting a mechanic to have a look at your engine,