return hose

Apoogied for starting another thread so soon after the last but I've done a leak back test and have a couple of questions about what I found.

First of all, I reported white smoke when revving on my last thread. It's not white, it's grey.

The leak back test showed three of the vials filling evenly with number four a bit behind/slower to fill. But not massively.

Unless it is a trick of the eyes the diesel in the vials looked a little cloudy. Don't know whether that is to be expected after passing through the system.

I had to clamp the return hose because with the engine running there was a lot of diesel coming out of it. Again, not sure how much to expect or whether the volume - much more than a trickle - indicates a problem. I did change the fuel pressure regulator seals recently.

Any thoughts great appreciated. Here is pic of vials.

How old is the fuel?

Nodge68 said:

How old is the fuel?

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About 6 - 8 weeks. I should also say I think diesel is getting into the oil - the level is higher on the dipstick than it should be. I assume that is to be expected with the large quantities of grey smoke, which I take to be unburned diesel.

How long did it take for the vials to reach the marks they are at, test should be done over two minute period, 20ml over 2 mins is the upper limit of leak back. each mark in the viral is 5ml

Arctic2 said:

How long did it take for the vials to reach the marks they are at, test should be done over two minute period, 20ml over 2 mins is the upper limit of leak back. each mark in the viral is 5ml

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I didn't time it. I thought it was pretty rapid apart from number 4, but I will do it again with timer. Does that time start from the first drops into the vial or from as soon as the engine turns over?

MGT said:

I didn't time it. I thought it was pretty rapid apart from number 4, but I will do it again with timer. Does that time start from the first drops into the vial or from as soon as the engine turns over?

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Soon as the engine starts, because you have to take into account the diesel in the tubes to the viral, and yes you have to clamp of the return pipe, otherwise you will have diesel everywhere.

When was your PCV filter last changed.

PCV filter done same time as I changed o rings on high pressure regulator - December just gone. I guess with filing tubes as well as vials it was at least two minutes.

Thanks for the reply.

I'm surprised so much comes out of the return hose when it is not connected to the injectors. If there's that much flow of diesel in the direction of the injectors how is fuel draining back to the tank from the injectors? Seems to be a contraflow in operation.