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Diesel Fuel filter drain plug

You are right about the chance of engine runaway, though I put the rag on a perforated tin lid above the air inlet near the battery, that can be pulled away quickly if things get messy.

I have asked Greasemonkey on pricing for the valve (and battery) from his salvage yard before taking more things apart, the link to the testing is clear enough, with the exception of the image link losses.
I had thought about closing the low pressure return with a surgical clamp last night and try cranking this morning, but rain has stopped play at the moment.
 
Clamping it would cause the pipe to explosively fly off and spray fuel everywhere if the valve was leaking... the system target while cranking is 300 bar! The pressure in that pipe is only low while it's venting back to the fuel tank.

But the valve is very easy to check, simply remove the small grey/black braided valve outlet pipe from the stub on the rail, plug it with a suitable screw, then reroute the stub output into a large container using plastic tubing... nothing should be flowing while cranking (or even idling). If it is then a new valve is required (about £90 from eBay with postage). I would never replace it unless I knew for sure it was leaking... it's very tight to replace and there's a risk of damaging things.

If it's not that valve then you'll need to test the injectors for excessive leak-back similarly using pipes and containers to simultaneously measure and compare the leak-back volumes and see if one (or two) are obviously much higher than the least example. I see the same seller also has recent injectors for sale.

But I still think it's odd that simply draining the fuel filter has caused this non-starting problem. Did it always start OK before you did this draining task?
 
I wouldn't shut off the pipe completely, (I doubt I could with the surgical clamps anyway) this would be just to get the car running. If it does start of course then it would suggest there is leakage through the valve in the first place.

The car has only failed to start when warm on about six occasions over the year but I've walked away on the last two and waited for an hour, if you recall I did try releasing pressure in the tank a fortnight ago which on the surface appeared to help but it might have been coincidence. It has got more frequent though but this might tie in with the battery losing its edge.

Im also wary that the fuel filter is directly above the exhaust with no shielding.

Still awaiting Greasemonkey on pricing for both bits.
 
Channel Hopper said:
I wouldn't shut off the pipe completely, (I doubt I could with the surgical clamps anyway) this would be just to get the car running. If it does start of course then it would suggest there is leakage through the valve in the first place...
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300 bar = ~4,500PSI. The pipe would simply detach itself from the rail if you tried using a clamp to stop the leakage through the valve.

If you're going to fiddle about with it then you may as well take the extra 5 minutes to perform the leakage test that would conclusively prove that the valve is faulty or not (you've spent more time posting about it than the test would take!). As I said, this valve leaking is a very common problem and the number 1 reason for poor starting.


Channel Hopper said:
...The car has only failed to start when warm on about six occasions over the year but I've walked away on the last two and waited for an hour, if you recall I did try releasing pressure in the tank a fortnight ago which on the surface appeared to help but it might have been coincidence. It has got more frequent though but this might tie in with the battery losing its edge...
Click to expand...
Yes, I recall. The problem of excessive leak-back from the rail to the fuel tank (whether over-pressure valve or an injector) normally manifests itself when the engine is warm (and the fuel flows a tad faster).


Channel Hopper said:
...Im also wary that the fuel filter is directly above the exhaust with no shielding...
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I remember telling you that there was an exhaust manifold het shield (and how to tell by the number of bolts whether it was an original welded type or the later cast type). Are you saying that the exhaust manifold shield on your car is missing?


Channel Hopper said:
...Still awaiting Greasemonkey on pricing for both bits...
Click to expand...
Surely it's a waste of time and money to buy replacement parts without diagnosing the faults? Especially when diagnosis is so simple and swapping parts (especially the injectors) is so difficult?
 
I had asked about the new Bosch battery in GMs Accord which would constitute the majority of the shipping weight, but have followed your advice.

Diagnosed, based on the blind instructions on the other thread, but let me know if I've got the correct pipe. There is no leak from the relief valve / black pipe into the bottle. Only a dribble from the main block to the left of the engine after ten seconds of cranking.

tMUsdv1.jpg


lVsVQZX.jpg
 
The reason I was hesitant to carry this out (notwithstanding the flooded conditions on the road after last night, and the wasp nest in the tree nearby) is the need to take off the engine cover once again.

The last owner has used different spacers which foul the 6mm threads and I am forever dropping either these, or the rear two rubber bungs onto the subframe, or under the car, one of which is now in the water. :(
 
No, that picture shows that you've conducted a test on the diesel pump rather than the fuel rail. The fuel rail is under the engine cover, high up at the front (all the metal pipes to the injectors run from it). The over-pressure valve is on the drivers side end, while the pressure sensor is on the passengers side end. Before the end on the drivers side there is a small (3 or 4mm OD) stub for the valve output, onto which is pushed a black/grey cloth clad pipe... that's the pipe you need to pull off and block, then connect a new pipe onto the stub to feed any output into something like a 2L coke bottle. It is a great shame that the Civinfo thread on this subject (to which I contributed) has lost its pictures.

Just leave off the engine cover while problems are on-going. It'll make your life much easier. The M6/10mm AF screws, washers, blind nuts, etc., needed to make a decent job of refitting it are available from Screwfix for pennies.
 
Ah, Bolox.

The text in the original article suggests the left side of the rail/engine

Look at the engine. The fuel rail is the tube with several brass nuts with narrow metal tubes (fuel lines) attached. To the left hand end of the tube, easily missed, is what appears to be a 17mm bolt. Close by is a black braided flexible tubing (low pressure fuel return pipe).
 
Channel Hopper said:
Ah, Bolox.

The text in the original article suggests the left side of the rail/engine

Look at the engine. The fuel rail is the tube with several brass nuts with narrow metal tubes (fuel lines) attached. To the left hand end of the tube, easily missed, is what appears to be a 17mm bolt. Close by is a black braided flexible tubing (low pressure fuel return pipe).
Click to expand...
Yeah, that is confusing without pictures. The author has wrongly defined 'left' as from his view point rather than from the drivers position... a common (yet understandable) mistake. The '17mm bolt' referred to is the end of the over-pressure valve (should not be undone without using a 6-point socket, as it can be terribly tight).
 
OK, located the correct tube on the drivers side (near glowplug 4) , but had to trace back to the passenger side as it wouldn't budge. No fuel comes out during cranking.

Z5jpwwL.jpg
 
Doesn't look like you bothered to plug the pipe that goes back to the fuel tank with all the other returns? Didn't fuel come out of that pipe? It should, if the fuel pump is working and the fuel feed from the tank is unobstructed (obstructions could include an air lock).
 
Channel Hopper said:
OK, located the correct tube on the drivers side (near glowplug 4) , but had to trace back to the passenger side as it wouldn't budge. No fuel comes out during cranking.
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btw, if you ever got round to downloading the ESM ( link --> http://typeaccord.co.uk/forum/topic/19286-haynes-us-accord-workshop-manuals/page-2 ) there is an xcellent diagram of the i-CTDi fuel system. Open the ESM, select year 2004 (or 2005), select CN2, click on "shop manual", then in the search box type "fuel supply" (without quotes), click on the "magnifying glass", then open "Fuel and Emissions System Description - Fuel Supply System Diagram"
 
Jon_G said:
Doesn't look like you bothered to plug the pipe that goes back to the fuel tank with all the other returns? Didn't fuel come out of that pipe? It should, if the fuel pump is working and the fuel feed from the tank is unobstructed (obstructions could include an air lock).
Click to expand...
No fuel from that pipe (I had blocked it though with part of the latex glove (image is before I started cranking)

So no fuel from the tank, I'll check fuses in an hour.
 
freddofrog said:
btw, if you ever got round to downloading the ESM ( link --> http://typeaccord.co.uk/forum/topic/19286-haynes-us-accord-workshop-manuals/page-2 ) there is an xcellent diagram of the i-CTDi fuel system. Open the ESM, select year 2004 (or 2005), select CN2, click on "shop manual", then in the search box type "fuel supply" (without quotes), click on the "magnifying glass", then open "Fuel and Emissions System Description - Fuel Supply System Diagram"
Click to expand...
I had (May 13th) Never thought I'd need it for draining a fuel filter though
 
Channel Hopper said:
No fuel from that pipe (I had blocked it though with part of the latex glove (image is before I started cranking)

So no fuel from the tank, I'll check fuses in an hour.
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I'm confused by this post. If you had blocked it then no fuel could have come out, therefore you can't know if fuel pressure was present in the system or not.

The fuel delivery is mechanical, not electrical. Fuses are irrelevant.
 
freddofrog said:
btw, if you ever got round to downloading the ESM ( link --> http://typeaccord.co.uk/forum/topic/19286-haynes-us-accord-workshop-manuals/page-2 ) there is an xcellent diagram of the i-CTDi fuel system. Open the ESM, select year 2004 (or 2005), select CN2, click on "shop manual", then in the search box type "fuel supply" (without quotes), click on the "magnifying glass", then open "Fuel and Emissions System Description - Fuel Supply System Diagram"
Click to expand...
Is it a mechanical pump ?
 
The latex glove (finger), sealed with wire tie would have trapped anything that came out. After cranking it remained dry.

Are there any other bleed points beyond that on the filter top ?
 
Channel Hopper said:
Is it a mechanical pump ?
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Yes. The diesel pump housing contains two co-located pumps driven by a shaft from the back of a cam shaft, one pump generates the high pressure (1600 bar) injection force while the other is a 'lift' pump that sucks up fuel from the fuel tank. But it cannot easily lift fuel from the tank if the pipes are full of air, hence the rubber bulb and the bleed nut (and why it's a really bad idea to let cars like this run out of fuel). 8th gen diesel Accords with the i-DTEC engines did have an additional electric pump in the tank to avoid all this unpleasantness...

No more specific bleed points. But you can crack open any joint on the rail or an injector to make your own... in fact that might be a good idea, just to double check that you have absolutely no fuel being pumped up.
 
I did crack the - passenger side - 17mm bolt at the top of the rail system following the filter bleed and hand pump out as much as I thought was needed but will try again.
 
Channel Hopper said:
I did crack the - passenger side - 17mm bolt at the top of the rail system following the filter bleed and hand pump out as much as I thought was needed but will try again.
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No, I meant that you should crack open a joint and see if fuel spews out while someone else operates the starter motor.
 
just a thought ......when was the last time fuel went into the tank, and was the fuel diesel ?
 
Five days ago and yes, it was diesel.

Tomorrow morning - after charging again - is undo the same joint that I loosened to get injector 4 out when replacing the copper seal, I can see anything that leaks/sprays out from the drivers window,
 
Jon_G said:
Yes. The diesel pump housing contains two co-located pumps driven by a shaft from the back of a cam shaft, one pump generates the high pressure (1600 bar) injection force while the other is a 'lift' pump that sucks up fuel from the fuel tank. But it cannot easily lift fuel from the tank if the pipes are full of air, hence the rubber bulb and the bleed nut (and why it's a really bad idea to let cars like this run out of fuel). 8th gen diesel Accords with the i-DTEC engines did have an additional electric pump in the tank to avoid all this unpleasantness...

No more specific bleed points. But you can crack open any joint on the rail or an injector to make your own... in fact that might be a good idea, just to double check that you have absolutely no fuel being pumped up.
Click to expand...
She's going

It turned out to be the pump was dry, so whilst I had removed air up to the 17mm bolt on the inlet, there wasn't enough vacuum in the pump to scavenge fuel through, then out to the 'go' parts.

Cracking the pump outlet, cranking and using the hand pump at the same time got diesel through it, then cracking at the injector 4 pipe got the last of the air out. Nipped up and let idle for ten minutes, then took for a short spin.

Thanks for all the help.
 
Yes [emoji106] [emoji122] result

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For future reference I would suggest using a vacuum hand pump to draw air out.

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honda_saj said:
For future reference I would suggest using a vacuum hand pump to draw air out.

Sent from my C6603 using Tapatalk
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Where would that connect to ?

I'm still slightly convinced there is another underlying issue that has caused the earlier problem with starting when hot, despite the check/elimination on the relief valve. Does the low pressure side of the mechanical pump have any known weaknesses ?

I had also looked at the possibility of air pressure in the fuel tank being in some way a symptom but did not get to recreate the problem. There might also be a pinhole or seal leak in the system of course, but that means getting underneath to check.
 
But you didn't actually test the over-pressure valve, as the fuel pump wasn't producing output when you thought you'd done the test. And, so far as I know, you've not tested the injectors for excessive leak-back either. Those are the usual causes of poor starting, especially when warm.
 
Jon_G said:
But you didn't actually test the over-pressure valve, as the fuel pump wasn't producing output when you thought you'd done the test. And, so far as I know, you've not tested the injectors for excessive leak-back either. Those are the usual causes of poor starting, especially when warm.
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And, back to square 1.

Tried starting today and OK for first ten seconds, then died.

Looked under car after cranking to find a pool of diesel dripping from the subframe on the left, directly under the fuel filter. Trouble is, the pipes and filter are as dry as a bone, right down to the device just underneth it where the flexible pipes go.

I'll try to trace where it is coming from, but as far as I can see it's not where I've been working.
 
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