WVO: solvents for cleaning up the fuel system and engine?

mosheshimon · Post by **mosheshimon** » Tue Jul 14, 2009 9:41 pm

I suspect that my BX turbo-diesel is collecting films of sticky gummy deposits in places where it matters, having been run on finely-filtered WVO for a year (with a 2-tank system).

I have heard recommendations to run it on regular diesel with added solvent(s) for a short while to dissolve away all the accumulated gunge.

Can anyone advise me on which solvents are best/safest and what sort of blend concentration to mix them/it in, and for how long to run the car on that blend to complete the clean-up? ...and anything else I ought to know about this?

Thanks in anticipation,

MULLEY · Post by **MULLEY** » Tue Jul 14, 2009 10:18 pm

You suspect, we'll need more clues for a diagnosis?

Have you changed the fuel filter or checked it? If thats a bit gunged up, replace it.

If you want to make sure the engine isnt getting gunged up, then just use some bio-diesel (a natural solvent) mixed with diesel in a 50/50 split. Run a full tankful & then check the fuel filter again, if its gone a greyish colour then its having the desired affect (carbon & other shit from the engine. I'd run another tankful of 50/50 then change the fuel filter again.

If it feels like your car is down on power, it may be worth checking the fuel tank filter which is hidden under the rear seat. Mine was gunged up & was stopping/reducing the flow of fuel.

REMEMBER: You can re-use the fuel filter if you clean it, which saves a few quid.

mosheshimon · Post by **mosheshimon** » Tue Jul 14, 2009 10:59 pm

Hey thanks.

I didn't even know that there WAS a fuel tank filter other than the Purflux canister-cartridge under the bonnet!

NB: how does one clean a fuel filter? I could do with saving a few quid safely!

Cheers,

mosheshimon · Post by **mosheshimon** » Thu Jul 16, 2009 1:31 pm

Hi, you asked for more details of suspected clogging from WVO blend...

Until last week all was fine. I had filled the tank with a blend of 10% petrol and 90% finely-filtered (1 micron) WVO plus a measured dose of Redex additive for non-standard diesel fuels. As usual with this mixture, the car started easily and ran well every time, from cold.

Then, after a couple of hundred miles or so, starting became slightly reluctant. After successfully starting it would conk out within about 5 seconds (no load) and need re-starting again. This now happens EVERY start time, after a total of about 500 miles on that same tankful, and may require 3 or 4 starting attempts to run without stalling a few seconds later. Pumping the accelerator pedal doesn't have any effect at first.

Over the same period, once it had finally started securely, the engine was very hesitant and under-powered, and struggled, shuddered, shook and kangaroo-hopped like a petrol car in the wrong gear. This continues every journey until the engine has reached almost full normal operating temperature, after which it all runs absolutely perfectly.

It has a two-tank system with heat exchanger, but prior to this last 500 miles it never needed the real-diesel 2nd-tank start-up because of the 10% petrol thinning in the WVO main tank, and I started/ran it perfectly from cold literally hundreds of times directly on the petrol-thinned WVO blend.

I had replaced the fuel filter cartridge with a brand-new one about 650 miles ago, shortly before the current problem arose. I have tried bleeding water/sludge from the little bleed-outlet at the bottom of the filter container/canister/bowl/whatever, but only pure clean fuel blend came out. No trace of the slightest drop of water or sludge.

As I said, once the engine has properly warmed up the problem disappears. This takes roughly a mile of driving following the ghastly starting procedure. The majority of my journeys are actually less than one mile, as I have intermittent walking difficulties.

Final very puzzling clue: all the above symptoms manifest themselves even using pure real diesel from the 2nd tank!!! It seems to be very slightly less severe with real diesel, but that might be my imagination.

I'm very worried: if it misbehaves like this in the current warm weather then maybe it won't start and run at all when the weather gets colder...

I hope that my detailed description of these symptoms help pinpoint the cause; please ask if there is anything else I can tell you!

With many thanks in anticipation of helpful advice,

jonathan_dyane · Post by **jonathan_dyane** » Thu Jul 16, 2009 1:46 pm

For a period I ran a Xantia on 100% WVO and a 306 (with Lucas pump) on a 50/50 wvo/diesel mix. At times I suffered similar problems with each car, however I didn't find this to be due to blockage (which usually manifests as a reduction in top speed/ability to rev as well as bad starting) although I suggest to rule this out you remove the tank sender and clean it's filter, and also blow through both the diesel feed and return pipes from the engine bay back to the pump with an airline or cycle pump (if you cut the cycle pump adapter thing in half, it can be inserted into a fuel pipe with a suitably tight fit).

My problems always resolved after running a few tanks of normal diesel, and I often wondered if it was my injectors beginning to clog up. Do you have the early seperate diesel filter, or the plastic housing on top of the thermostat housing?

mosheshimon · Post by **mosheshimon** » Thu Jul 16, 2009 2:45 pm

Hi, thanks for an encouraging post.

The fuel filter is nowhere near the thermostat; it's on the driver's side near the LHM reservoir, and it takes a paper-cartridge type of filter inside an Allen-key central-bolt-fixed removable canister.

Someone has suggested mixing Isopropyl Alcohol with the oil for a while to clear any gunge, and I'm hoping to get more feedback and advice on this idea too. (I don't want the car to get a hangover, it already gets the DTs every morning!)

Cheers

jonathan_dyane · Post by **jonathan_dyane** » Thu Jul 16, 2009 4:08 pm

No worries. The reason I asked about the type of fuel filter is that the type on the thermostat housing had a point that tends to clog and is not immediately obvious, but as you have the earlier set up this shouldn't be an issue.

I have in the past used isopropyl alcohol in a petrol car, to successfully deal with the issue of water in the petrol. This works due to the isopropyl absorbing the water and permitting it to pass through the carburettor jets and be burnt. In a diesel the last thing you want is for water to pass through the injector pump, so I suggest adding the isopropyl is best avoided.

Why not buy a bottle of diesel fuel treatment (Forte for example) but rather than adding it to the tank, remove the diesel filter bowl, empty out the fuel, and fill the bowl with neat diesel treatment and refit. Should the problem be injector deposits this may just shift them...

mosheshimon · Post by **mosheshimon** » Thu Jul 16, 2009 7:15 pm

Hi Jonathan

Thanks again for the further advice. I wish I were more knowledgable about such matters; I'm astonished that the engine can actually start and run (even briefly!) on such diesel treatment additive, added neat through the filter!

As for the issue of moisture being carried in the Isopropyl alcohol, it is well beyond my tiny brain (if any) to comprehend what harm it could do in that state, thoroughly dissolved in the fuel blend rather than as a separate liquid. Particularly in such miniscule proportions that none at all was actually visible in the filter housing. I guess it makes sense to those who have sense!

I assume that your warning would apply equally to ALL alcohols including Acetone (which another BXClub member actually recommended)?

Incidentally, referring to another posted reply, how does one wash/clean a paper-cartridge type of filter for re-use as new? Can I literally put it in the washing machine with a laundry load and expect it to survive the buffeting etc? Or should I wash it out in petrol/thinners? Or hand-wash it with a soft brush in a bucket of hot detergent solution followed by thorough rinsing in water? Or another method entirely?

Cheers,

MULLEY · Post by **MULLEY** » Thu Jul 16, 2009 7:45 pm

To clean the fuel filter, i get an empty & washed out coke bottle, cut the top off, place fuel filter in the bottle & then pour in a turpentine supstitute until the whole filter is submerged. This stuff can be purchased from B&Q etc...normally used for cleaning paintbrushes etc....

I then give the bottle a few mins of swirling without the turps spilling out the top of the bottle. You should see debris etc starting to settle in the bottom pits of the coke bottle, i leave it overnight. Filter the turps to get the crud out & re-peat the above process. Continue doing that until you think the filter looks about as clean as a new one or as its going to get. Take out of the turps & leave to dry naturally for a few days & then you can re-use when you next need to do this process on the filter thats already in the car.

Just out of interest, what type of diesel pump have you got?

The down on power sounds like the fuel tank filter is blocked, do you know how to access this? I was a complete newbie when i did it & its easier than you think & it wont cost you a penny to check either, bonus

jonathan_dyane · Post by **jonathan_dyane** » Thu Jul 16, 2009 7:46 pm

Believe me, I am no expert, however I have dicked around with most things automotive,

You could well be right with regards to the water not being an issue, but the fact is there is always water knocking about in tanks, and I would avoid risking it, IP's *really* don't like water.

On cleaning filters, I have, in an emergency (stuck at the side of the road) washed a blocked paper diesel filter in petrol to clean it. It worked, but the car took some starting with it reinstalled (now impregnated with petrol) and as the governor struggled with this alien substance and idle revs varied from near stalling to ITRO 2000rpm, I mused it was probably a fairly cruel thing to do, so should you use a solvent do allow it to evaporate before reinstalling...

I would just replace the thing when in doubt; they aren't dear and with the saving made from running on WVO one can surely stretch to the odd extra filter

I have heard of people warning against using Acetone in diesels for the above reasons; some advocate it as a fuel saving additive (didn't make any difference when I tried it...)

A diesel fitter recommended the tip with the diesel-clean stuff, and I have done it once (with the Forte) to good effect (an MOT...)

MULLEY · Post by **MULLEY** » Thu Jul 16, 2009 10:29 pm

I always have 2 filters, one in the car being used & a clean re-used spare to replace the one being used when required, so i just cycle each one so there's never any danger of a filter having any turps remaining on it as by the time i come to use it, its nice & dry. Can save quite a few quid over the year if you start changing the filter a lot because of getting paranoid about using wvo.

Post by **mat_fenwick** » Fri Jul 17, 2009 10:12 am

jonathan_dyane wrote:A diesel fitter recommended the tip with the diesel-clean stuff, and I have done it once (with the Forte) to good effect (an MOT...)

I've done this a couple of times...neither time with any quantifiable effect such as MOT emissions. However I did notice a marked performance difference on one occasion (where I suspected the engine had been neglected) in that it would pull generally in a gear higher on the same road. I would advise warming the engine before trying the neat injector cleaner, as it can sometimes be tricky to start!

mosheshimon · Post by **mosheshimon** » Fri Jul 17, 2009 2:02 pm

Hey you guys, Mulley, Jonathan and Mat,

Thanks SO much for the encouragement and advice. As I'm a total ignoramus I'm really grateful for all the guidance I can get.

My IP is the Lucas/CAV/Delphi type rather than the allegedly-superior Bosch. Someone told me that my filter housing is not the original one as that type usually goes with the Bosch IP. Apparently my car's original fitted assembly would have taken the spin-off/spin-on type of disposable complete canister rather than the paper cartridge insert. I prefer this one as it allows easy drainage of accumulated water/sludge.

Where/how do I find and access and remove the fuel tank filter? Do I need to get under the car (er, ...back problems!) or can it be accessed properly from inside the cabin/boot-space somehow?

With mega-thanks again

Long live the forum!

jonathan_dyane · Post by **jonathan_dyane** » Fri Jul 17, 2009 8:58 pm

The type of injector pump does not always have a bearing on the type of filter fitted.

I have to say, you're a braver man than me running such high proportions of veg through a Lucas IP, I hope the symptoms you are having is not the pump in its death throes, although the usual failure mode for a Lucas pump running on veg is for the pumping head to shear off with no prior warning...

Can't remember if I've have been into a BX tank, but would be surprised if it's not the same as any other PSA vehicle of the era (and indeed almost any modern car) where the tank sender/pipe fittings are accessed through a big round grommet under the O/S rear passenger seat.

Remove the grommet, wires (if the sender and pipe inlet/outlet is combined) from sender and pipe clips. These may be of the non-jubilee type, which can be opened with the use of a small flat bladed screwdriver under the hook part. Around the periphery of the unit is a threaded ring, which you can slacken with initial assistance from a blunt chisel. Once this is off, simply lift out the unit from the tank.

MULLEY · Post by **MULLEY** » Fri Jul 17, 2009 9:20 pm

Even with a twin tank system, i'd be wary of using veg oil with a lucas pump, but i guess if its upto temperature thats about as good as its going to get for not causing damage.

Out of interest, is the wvo in the additional tank in the boot or did you do it the other way round?

I presume over time, that some wvo will eventually filter back into the normal diesel tank, & thats what may have caused the tank filter to gunge up. Mine looked like it was coated in thick honey, yellow & sticky substance, no wonder no fuel was getting out of the tank.......

BX Club Forum