In Line Fuel Filter

[Chris]

Along with my missing tax disc, the postie brought this today.

I have had a couple of instances where the fuel has drained out of the fuel line and the truck wouldn't start. I also found when I bought the vehicle that the filter on the pick up had come off and was floating in the tank. When I changed the main filter there were all sorts of things in it - pine needles, twigs etc. What a difference it made changing it. I later replaced the filter again to bring all the service items into line only to find even more filth in the filter. So I am going to change it again today and stick this in line on the tank side of the filter. So not only can I see the fuel, but I can see what is being pulled through. There were many sorts available but this one does 8mm and 10mm line. I can see that this could be a simple, cheap and useful mod for a long trip to preserve your main filter's performance.

I got it here

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWNX:IT

Chris

 

[Chas]

Nice one Chris , I've just bought one.

 

[Chris]

OK, covered in derv now. I decided to have a go rigging it up without cutting the original fuel line. I like to make sure things work first. Only spare line I had was the clear stuff with the reinforcing in it. Being so cold the stuff is that rigid, I couldn't get it to seal properly and it dragged air in. So I have abandoned it for now. I need some rubber fuel hose (I can't find the bit in the garage) and then I can put in a whole new piece with the filter in. I would just have a crash team standing by when you start it up as watching the speed at which the fuel goes through might just stop your heart. It's like having a hole in the tank! What I can now do though is arrange the filter so that when I stop the engine, there will always be a head of fuel in the filter. If the line then drains back, there will always be enough held there to start the engine and pull fuel up the line.



Chris

 

[Chas]

arrange the filter so that when I stop the engine, there will always be a head of fuel in the filter. If the line then drains back, there will always be enough held there to start the engine and pull fuel up the line.Chris

Good tip, I'll remember that when I install mine

 

[Toby]

Hi Chris,

Aren't the stock fuel lines 12mm bore? You might need a couple of adaptors. I don't know about the current models, but the old style Walbros came with a gauze filter built in

All the best,
Toby
1990 HDJ80
1994 HDJ80

 

[Chris]

They are Toby yes. I had to fashion some adapters to make it fit this morning. But decent flexi pipe in 10mm will go onto the stock pipe at each end. Judging by the amount of fuel going through the filter, I don't think that the lesser pipe size will restrict flow. It's only an experiment. Could do with better sized filter to go straight on, but could only find 10mm

Not there yet, will twiddle in next few days.

Original fuel filter looked a lot cleaner this time around. No more pine needles.

Cheers fella

Chris

 

[dave b]

hi chris
I have had a few issues with fuel running back which turned out to be the primer pump on the filter housing.toyota wanted £117+vat so i got the universal pump and filter like the type on fords.I could only get 10mm adapters for the filter housing so just usded a couple of plastic joints 10mm-12mm and i havnt had any fueling issues using the smaller bore pipes.

 

[Chris]

Thanks Dave. Yeah, my primer pump is boogered too. No action there at all. Karl showed me the Ford trick. I may go that way. Many thanks for the reducing advice. I shall be doing that once I get a minute
Also thought about fitting a one way check valve.

Chris

 

[Chris]

OK, get this. Fitted the filter again the other day. Still a bit of a lash up, but managed to clamp it all up and keep the air leaks at bay. Now, very oddly, unless I am finally ready for the funny farm, it runs sooo much better. I mean smooth as silk and goes like a train.

Just now, I popped the bonnet for a looks see. Uh? Fuel had drained out of the filter. It must hold half a cup full. I had it positioned so that the filter held fuel even if you took the delivery hose off. Enough to get me half a mile I'd guess. Somehow, all that had drained out across an air gap. No, it hadn't leaked forward into the pump I am sure 'cos I have watched it in the past.

There was enough in the tube to start up - which it did and soon pulled fuel through. Again running as sweet as a nut. No smoke at all.

So tonight I ordered a one way check valve to put in the line. This should stop all of this. Why does it do it? Well, it seems that the primer pump on top of the filter housing is not only duff in respect of pumping, but it has failed as a non return device. So if you have poor starting but great running, this might be your problem. The NRV was less than a fiver.

Chris

 

[chriscolleman]

My 86 merc G has this additional fuel trap as standard. It's a clear mann pre-filter so you can watch for airbubbles and contamination. The in and out is designed to act as a siphon fuel trap.

The G doesn't need an electric fuel pusherpump as this is fitted and the fuelpump fitted on the IP kicks in fiercly when the engine is running. Churns the entire contents of the tank like it's going for a world record fuel mixing attempt.

Great stuff these clear pre-filters.

 

[Chris]

Just dragging you all up to date on this one. Having the clear filter has allowed me to watch the precious fluid draining back into the tank, pulling it up out of the IP so that the thing won't even start. Yesterday Postie brought the one way fuel check valve. That's gaffered it. No more fuel drain. Now you don't need to fit the filter of course but if you have been having fuel drain issues, get a 12mm one way check valve banged in there for a tenner or so and that should be the end of it. Simply cut the fuel hose and shove it in. You could get a new lift pump if you have more money than brain cells of course.

I shall tidy the whole affair up this weekend a post a pic or two. The engine is running much better too. If you suffer from any kind of short term fuel starvation, what you have by fitting the filter unit is in effect a reservoir of fuel to draw on that doesn't need lifting from the tank.

Cwis