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2002 112 CDI: Air Bubbles in fuel line

11K views 12 replies 5 participants last post by  Danny DeVito 
#1 ·
Hi All,

I hope someone can sure up a few things for me - I have read as much as I can find here but as usual everyone's experience is a tad different, so before I start go pulling stuff off....

We have had this Vito since new and it for the most part has been great. it's had a pretty easy life, serviced as per schedule so it's not thrashed at all. Lately we have had trouble kicking our Vito over in the mornings. Only happens first start of the day (i.e. after sitting all night) and after that it's 100% fine - no warning lights, no power loss, nothing, good as gold.

After spending quite a bit of time going through it and reading up whatever I can find here on the Vito forum, I am about to replace the fuel filter, which is due for replacement. What I have found though is that in the morning's:

Line No.1 (as per the pic) is empty at the filter. Tracing the line back to the RHS side of the covers, before it vanishes under the car, the line can be partially full, or if standing longer, empty to the last point you can see the clear tube (RHS of the cover).

Line No.2 used to also be empty in the morning but after having replaced the seal at the filter, is now holding fuel. Tapping this line with a screwdriver before starting though, air bubbles travel back up towards the filter and after the van is running, fuel heading out of the filter on this line is visibly aerated for some time.

I have read that replacing the seals at No.3 can possibly fix this.


The other thing I have noticed is that following line No.2 down under the filter, there seems to be diesel residue on the line itself right at the bottom. I have not pulled out the air filter etc. to get a good look (or replace the o-rings) but only this and the adjacent line do seem to have the diesel residue on them - there is no leakage on the floor under the van or seemingly anywhere else. I am wondering if the seal down here at No.2 is totally shot and doing a slow leak, hence letting air in the system.

If there's anyone here that has had a similar or the same experience, I'd really appreciate hearing from them. Right now, it seems that the issue is the filter and connections to and off it.

Cheers and beers!

Gerard
 

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#8 ·
Hey tomhib13, wasn't the filter. Replaced it, and while there is a significant improvement in performance (which makes me wonder the last time the previous shop changed it), still having issues. It goes into the shop on Monday for them to look at, as after removing all the covers, air box etc. there was still no way I could get to two of the low pressure seals which are hidden directly behind the engine mount.

In regards to the seals, I picked them up on ebay. Just look for 'Vito 122cdi low pressure fuel line seals'. They should be green in colour.
 
#7 ·
tomhib13, after a lot of poking and prodding, I've put it down to the fuel filter itself. Line out (#2 in the image) is holding diesel so the issue is to do with #1 , which is diesel in - I did a test and actually watched the diesel drain back down the line after the engine was turned off.

The filter is well due for renewal, I don't think they did it last service, so I've just ordered one. I'll also change the rubber attachment and pinch clamps for the fuel line to filter connection to make sure everything is sealed.

In regards to the possible leak, I am guessing it could be one of low pressure o-rings, most likely the monster to get to one at the end of the fuel filter line. I spent a long time watching the area and if there is a leak, it's pretty small at the mo.
 
#9 ·
Hey tomhib13.. if you're still watching this.

We ended up replacing all three low pressure fuel lines and fitting and the Vito's like new. Starts with no issue and it's found its old pickup and go once again. Turns out after 11 years in Australian weather, they were more than past their used by date and were sucking air and spurting diesel.
 
#12 ·
Those o-rings can be bought at a dealership too.

$4 each :eek

I thought it funny when I went in there.

I asked the parts girl about them, she walked back two steps, reached into a top drawer..."You mean these? Don't need your vin for this".

I grabbed 10.

They're just down the road from my place. So I paid for convenience :smile
 
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