Air in fuel issue

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TRANSPORTER
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Joined: 10 Dec 2019, 16:24

Air in fuel issue

Post by TRANSPORTER »

Hi Guys, first post so introduction first, running a 406 2.1 diesel, on the 8B engine. She's an R plate so 98 if memory serves me right. Runs like a dream and give me 53+ mpg so not complaining one bit. I carry out as much work on her as I can ( use of ramps etc at work ) and keep her going as best I can.
My problem at the moment ( after I've just changed lower wish bone N/S and auxiliary belt, 2 1/2 hours!!!!! just for the belt ) is air in the fuel lines.

Now I've done some research as this has been an ongoing problem for a little while now for myself and others, So far I have changed the primer bulb but had to use the old one way valve and other fittings as the fittings that came with it were different ( straight as opposed to right angled ) I then changed as many of the pipe clips for new jubilee clips, greased all pipes when refitting to help create an air tight seal.

Yesterday after more air bubbles were seen in the fuel lines I got the clingfilm out and wrapped the primer bulb and all pipe joins to try and see if that would show me where the leak was coming from. To no avail as bubbles were still in fuel lines.
I thought I had narrowed it down to the actual fuel filter housing as the bubbles were for a little while only coming from there to the FIP and not from the primer bulb to the fuel filter. I have a new fuel filter and a base gasket O ring ready to install just to take them out of the equation ( both genuine Peugeot ). But after a little while bubbles were coming from the primer bulb direction as well.

When I switch the engine off small bubbles can be seen leaving the FIP going towards the fuel filter but not actually getting there and also tiny bubbles from the primer bulb area also travel towards the filter but don't actually get there. I have also bled the fuel system as per haynes manual twice now.

Also since fitting the new primer bulb I noticed the other day that it is being sucked in like there is a vacuum in the system, I had not noticed this before but every commute to work now and its almost flat when I stop. I have opened the fuel cap to allow it to vent to see if that will release it but it doesn't. It will however over a period of approx 10 sec re-inflate itself to normal shape once I have turned the engine off.

I'm now looking at by passing all the pipes under the bonnet and connecting two new clear pipes direct from the connection on the bulk head (white tang quick release ) to the primer then straight to the filter housing then from there straight to the FIP. This will hopefully tell me if if the old pipes had any problems.
The main question I have is the quick release connector ( white tang ) what size would I need? I have measured the pipe and its just over 10mm (10.78mm on my vernier ) I have tried Peugeot but they no longer sell them, and my local scrap dealers although they have them fitted to cars they would not allow me to remove them due to environmental issues. I don't want to waste money buying the incorrect size as I want to get the pipe system made up in one go before fitting it and testing.

Apologies for the long first post but any help greatly appreciated, thanks in advance.

doctle
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Re: Air in fuel issue

Post by doctle »

When I had the 307 there was air in the fuel lines and it was very difficult to start. I replaced the plastic fuel pipes with rubber and instead of the push on clips I used jubilee clips. I couldn't see the bubbles but once the primer went hard I knew they were gone. It worked fine from then on.

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white exec
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Re: Air in fuel issue

Post by white exec »

Be careful using jubilee (worm drive) clips on small hoses. These clips, at small sizes, are not properly circular (the rigid section containing the screw) and often distort the hose, making an air leak more likely.
Better to use a properly circular hose clip.

Same problem can arise on the suction pipe between HP pump and LHM reservoir on hydropneumatic systems, and on the small return pipes on the reservoir 'octopus'.

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van ordinaire
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Re: Air in fuel issue

Post by van ordinaire »

Hence the existence of specific fuel pipe clips! Although, pre-injection, we got away with "jubbly" clips for years.

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Re: Air in fuel issue

Post by TRANSPORTER »

Cheers for the replies guys I’ll change out the jubilee clips for the correct size and type shortly, although does anyone know the correct size required for the fuel feed quick release white tang connector?

doctle
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Re: Air in fuel issue

Post by doctle »


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Re: Air in fuel issue

Post by TRANSPORTER »

Yep happy with them mate, it’s the white tang quick release fuel line connector that I need the correct size for so that I can start the test.
As I can’t seem to buy them from the main dealers or motor factors I’m having to rely on online shopping for them, so that involves waiting and hoping I’ve measured correctly etc

doctle
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Re: Air in fuel issue

Post by doctle »

I couldnt find any place that sells them either other than ebay sellers from china. I assumed you had to buy the pipes hence i used the jubilee clips.

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Re: Air in fuel issue

Post by TRANSPORTER »

Yeah I’ve ordered a 10mm one from a uk eBay seller, only trouble is they use Hermes as a postal service so it’s taking a week to travel half the length of the country which is abit of a joke. Anyway hopefully here by Saturday and then I can set to work next week.

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van ordinaire
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Re: Air in fuel issue

Post by van ordinaire »

Funny last couple of pre-packed fuel line I've bought came complete with 2 clips - mind you, it IS an expensive way to buy it (even from Trago Mills!). Ironically you can only buy the proper clips from the same places that sell fuel line off the roll - & they only seem to turn up at car shows. Just (literally) remembered, somewhat improbably, you can get both from Vehicle Wiring Products Ltd (www.vehicleproducts.co.uk) not cheap but good quality stuff & good selection (no stainless clips though, although they are available. As for size, you need to know the o.d. - &, helpfully, VWP's catalogue gives o.d. & bore of all their hoses - so, pull off that "quick release" (what a misnomer!) & measure the pipe.