Filter question

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MikeT
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Re: Filter question

Post by MikeT » 01 Oct 2014, 14:44

lazza wrote:Thanks for the replies

MikeT could be onto something there. Yes it's grey smoke and acclerating - decelerating idle

Symptoms much better with normal diesel, but i'd really like to get back to using veggie oil... where is the timing device on the pump?
Grey smoke is a different kettle of fish.

Hmm, where's the timing device. Eeek! Now you're really testing my god-awful memory as it's been years since I dismantled a pump. This is the best pic I have of where the timing actuator is housed (wires and protective cover showing where it's bolted on. To grasp the perspective, we're looking at the underside of the pump (shaft end down - distribution ports up)

Image

lazza
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Re: Filter question

Post by lazza » 05 Oct 2014, 10:51

Cant see one of those on mine- my pump is Bosch pump no: 0460494412 VE4/9F2250R445-8

MikeT
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Re: Filter question

Post by MikeT » 05 Oct 2014, 15:25

lazza wrote:Cant see one of those on mine- my pump is Bosch pump no: 0460494412 VE4/9F2250R445-8
Best not take any more advice of me at this point, my memory's obviously worse than it was as I completely forget about the variances of the IP add-ons fitted to Xantia's over the years. AFAIR, there's three main variances when it comes to injection timing;

1. Mechanical (timing is reliant purely upon pump pressure, which varies with engine speed, acting on the plunger to advance the timing)
2. Cold-start advance (when engine is cold, the mechanical plunger is further advanced by an electric solenoid)
3. ECU controlled (timing is varied according various sensor feedback)

The photo I posted shows mine which is ECU fully electronic timing. Yours, I would guess uses cold-start advance. If you can identify if and what timing control your pump uses, you could check those systems for correct operation and if they're working fine, it's possible your IP needs an overhaul as I'd be suspecting inadequate fuel pressure due to wear or contamination.

lazza
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Re: Filter question

Post by lazza » 05 Oct 2014, 18:38

YEs I have played around with the cold-start advance (which is mechanical), but it didnt seem to improve things.

An overhaul once again of the fuel pump, I cant say is something I'm looking forward to- I'll check the injector leakage pipes and replace them anyhow--- i'd like to at least look at the injectors as I presume that's alot easier than dismantling the pump?? is it easy?

Then having disgarded all the other options, I suppose I may have to dismantle the pump once again ... groan

KP
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Re: Filter question

Post by KP » 08 Oct 2014, 11:07

Youd be better sourcing another pump from the UK where prices are cheaper and then rebuilding that and then refitting is a much quicker process but timing is more critical but should be fine seeing as you have already done one.

Injectors are not too hard to remove but i dont think they are the issue as otherwise when accelerating you would have the same lumpyness or a lack of power.

leak off pipes could be causing an issue as they will introduce air into the system but they could also help you find out if one of the injectors is leaking back too much fuel, and the test is very simple to do.

Have you tried an 'italian tune up'? get the engine red hot and give it a good thrashing as that could help clear out any debris lurking in places.

Also the VOW heat exchanger.... Just get rid of it as they aren't any real use where you are. Even if it does implant some heat into the veg, on a cold engine the pump and pipe work soon saps the heat out of the fluid very easily. It would be better replaced with a cheap small 12v pump motor to assist in pickup of cold fuel but as you are somewhere that i doubt it gets below 10'c at the colder points in the year you should be fine without any of the stuff. Also the Fuel Filter housing actually helps heat the fuel a little as well :) This can easily be modified to always heat the fuel and can be found online thru a quick google search :)

lazza
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Re: Filter question

Post by lazza » 10 Oct 2014, 09:55

Thanks very much for your reply- I reckon I'll try both the Italian tune up.. :)

Then i'll look at the leak off pipes- how do I do the test to see if too much fuel is leaking back?

Cheers
Larry

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myglaren
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Re: Filter question

Post by myglaren » 10 Oct 2014, 16:29

Make a test kit (or buy one of course)
Image

Then follow this procedure, more or less:


lazza
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Re: Filter question

Post by lazza » 09 Nov 2014, 22:21

HI Forum,

On this issue, i've been running on normal diesel for a few weeks now, and it's clear that there is an idling issue- less acute than with vegetable oil, but still there.

I've adjusted the idle adjustment screw to its minimum, but the revs in idling still seem way to high (and slightly unstable)... any suggestions??

MikeT
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Re: Filter question

Post by MikeT » 15 Nov 2014, 18:24

lazza - can you outline the exact steps you took to "adjust the idle"? There's a set procedure that's more involved than turning one screw and as mentioned before the fast idle over-rides it if it's broke.

lazza
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Re: Filter question

Post by lazza » 15 Nov 2014, 18:49

errr, cant sorry, it was a while ago. I readjusted the fast idle and now it doesnt over-ride- however it may be broken as it doesnt move much now between hot and cold- could the thermostat be broken?

MikeT
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Re: Filter question

Post by MikeT » 15 Nov 2014, 19:07

The other device that might have thwarted your efforts is the anti-stall.

I don't know which fast idle your system uses, I'm aware of at least two (vacuum and waxstat) though there could be more.

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Stickyfinger
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Re: Filter question

Post by Stickyfinger » 15 Nov 2014, 19:40

was looking about on a similar subject (warning the floor with solar at my workshops) and found this

I present you with the Velcro fitted electric filter warmer....may help, may not, but interesting.
http://engineheaters.co.uk/filter_heater.html
Image
Image

lazza
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Re: Filter question

Post by lazza » 17 Nov 2014, 16:12

Thanks for the replies

I'm actually leaning towards swapping the VWO heater for a 12V assistant pump for the Bosch main pump, as the forum seems to think this is the best way to overcome any starting issues-

Could anyone send me a link to the type of pump that would be ideal??

thanks
Larry