Filter question

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lazza
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Joined: 08 Sep 2008, 09:04

Re: Filter question

Post by lazza » 02 Sep 2014, 13:42

It stutters for at least a few minutes. Just sounds like it's not firing evenly until the revs go up and then it's fine.

Could it be the injectors? Are they worth looking at? is it a big job?

MikeT
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Re: Filter question

Post by MikeT » 02 Sep 2014, 15:41

lazza wrote:It stutters for at least a few minutes. Just sounds like it's not firing evenly until the revs go up and then it's fine.

Could it be the injectors? Are they worth looking at? is it a big job?
If 1100rpm clears up the stutters you could try fixing the fast idle system. I just use a bit a right foot if I'm bothered.

lazza
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Joined: 08 Sep 2008, 09:04

Re: Filter question

Post by lazza » 04 Sep 2014, 20:43

Ok, i'll try that

Can anyone tell me though, how big a job it is to take the injectors out and inspect them, and if necessary, change them??

Thanks
Larry

oscar
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Re: Filter question

Post by oscar » 07 Sep 2014, 14:58

Don't forget the first minute is cold/thicker oil so get that used to on mine and makes it harder to compress also till warmed up

lazza
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Re: Filter question

Post by lazza » 07 Sep 2014, 17:48

I've been trying to diagnose the route of the problem and when it's starting with vegetable oil, the engine acclerates slightly then decelerates, accelerates again... basically it's very uneven when it should be ticking over...

there must be an explanation for this?? it didnt used to have such a problem with Veggie oil... can anyone help?

homeruk
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Re: Filter question

Post by homeruk » 07 Sep 2014, 18:39

You probably have already checked this but have you checked for power at the glowplugs?

MikeT
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Re: Filter question

Post by MikeT » 07 Sep 2014, 19:30

lazza wrote:I've been trying to diagnose the route of the problem and when it's starting with vegetable oil, the engine acclerates slightly then decelerates, accelerates again... basically it's very uneven when it should be ticking over...

there must be an explanation for this?? it didnt used to have such a problem with Veggie oil... can anyone help?
MikeT wrote:
lazza wrote:If 1100rpm clears up the stutters you could try fixing the fast idle system. I just use a bit a right foot if I'm bothered.

lazza
Posts: 234
Joined: 08 Sep 2008, 09:04

Re: Filter question

Post by lazza » 23 Sep 2014, 19:10

HI.

Well I've tried just about everything- Changing the glow plugs, fuel filters, air filter, fast idle, and the problem still persists.

The car starts but there is lots of white smoke and acclerating and decelerating, until the engine is really heated up- then it idles more or less ok, but not perfect. I never used to have this problem with veggie oil and it's still not cold here yet. I'm going to have to go back to normal diesel until this is sorted i think.

I'm thinking that the fuel pump needs another overhaul.... or could it be the injectors??

Any assitance greatly appreciated

MikeT
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Re: Filter question

Post by MikeT » 24 Sep 2014, 20:25

I'm sorry if I'm at all frustrating your efforts by not addressing the injector theory but I do personally feel it's a red-herring tbh. The fact the engine runs well when it heats up is a huge flag for my lack-of-sufficient-ignition-heat-theory.

(sorry if this was already covered). You say you changed the glow plugs but are you satisfied they are actually glowing when needed? (Did you also test the ones your removed to verify if they had failed?) A clue to this is seeing a large voltage drop when the glow plug light is on, for instance. I recall mine would drop very noticeably with new glow plugs fitted. Just attach a MM to the battery and rest it on the wipers/screen so it's display is visible to the driver. Get in the car, observe the battery voltage (should be about 12.3v or so) and turn the ignition on so it's energising the glow plug (do not crank the engine). The MM reading should instantly drop by several volts. Any less drop (or none at all) indicates not all GP's are peforming as hoped.

Let us know if changing to regular diesel (you'll have to "use up" what's in the fuel pipes, filter, pump etc first) makes any difference. I'd expect the problems to be less severe (but still evident starting on diesel) as veg oil is much thicker. Talking of veg oil, which type are/were you using (rapeseed, sunflower, soya, other)?

lazza
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Re: Filter question

Post by lazza » 25 Sep 2014, 20:44

HI, thanks for the reply. If you think the injectors is a red herring, i bow to your expertise.

I think the voltage drops to about 9V at the glow plugs.. I will check current draw etc and make sure they are getting the power they need over the weekend.

I've just switched to normal diesel, so we'll see how it goes...

To be honest it seems like a revving problem on idling... although i did fiddle with what i thought was the adjustment screws.... Maybe someone send me a picture/diagram of all the various adjustements I could make on a bosch pump???

MikeT
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Re: Filter question

Post by MikeT » 26 Sep 2014, 18:17

expertise teehee. no, I'm just another person who has to self-teach and learn from others to maintain his car and when I post/respond I'm only speaking from my own experience and learning. Your problem may well be down to an injector and I welcome other members chipping in with their thoughts as I may learn something I'm not aware of. But from my perspective and how I would tackle the list of possibles is to go with what I do know and prioiritise which to tackle first, which is why I put injectors way down the list of considerations. I personally cannot advise how to check/test/determine injectors being the cause of the symptoms you describe other than a spray pattern test (pop testing) and I would assume a simple google search would furnish you with better info than I could.

Ditto for the Bosch pump adjustments. It's well documented and freely available with a google search. IIRC, there's really just a few adjustments the DIY mechanic should be concerned with - idle(s), off-boost and on-boost enrichment - none of which I can envisage being the cause of white smoke on cold starts only. Do be aware, that if you set these according to how it behaves on cold-starting (where there is obviously an unresolved problem with your car) you may introduce more problems in normal running (ie, when the engine is warmed up and not emitting white smoke/poor idle).

lazza
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Re: Filter question

Post by lazza » 29 Sep 2014, 16:00

sorry, what is off-boost, on-boost enrichment?

MikeT
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Re: Filter question

Post by MikeT » 29 Sep 2014, 16:37

lazza wrote:sorry, what is off-boost, on-boost enrichment?
It's the mechanisms for setting the fuelling with and without turbo boost. The flying saucer part houses these.

On a different note though possibly related, someone in another current thread mentioned a fault in the timing device could cause the reported symptoms (grey smoke) and I wondered if it fitted your symptoms. I think it was Jim that stated if air is being sucked into the fuel system starving the pump of adequate fluid pressure, the timing device could be obstructed in obtaining the correct timing which is suggested the cause of the grey smoke and poor idle (sometimes causing it stall) in this case.

I know we covered air leaks before but perhaps it's worth double-checking? As mentioned in the other thread, common causes of air leaks are the injector leak-off pipes (which feed back into the IP). It's really cheap fix and worth doing if the pipes look aged/cracked or brittle.

Equally, any polymerisation of veg oil can obstruct the free operation of this device causing the same symptoms. Though I've not experienced or suffered any problems from this "gunk" in my system, I have seen it in two other pumps run on alternative fuels.

Northern_Mike

Re: Re: Filter question

Post by Northern_Mike » 29 Sep 2014, 16:40

lazza wrote:sorry, what is off-boost, on-boost enrichment?
Different levels of fuel are needed for running on and off-boost. Generally, the more air you pump in, the more fuel you need (and vice-versa). The flying saucer part on the diesel pump contains the bits that make this work.

Sent from my SM-N9005 using Tapatalk

lazza
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Re: Filter question

Post by lazza » 30 Sep 2014, 19:50

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?