200tdi smoke!

discomania said:

700BAR? Don't know where you’re getting your information from but the fuel flows back at about lift pump pressure, one bar or two tops. Think about it, if it was 700 bar (about 10000 PSI) I think our return lines made up with bits of rubber pipe and hose jubilee clips would we blasting off left right and centre.

These little holes in diesel system returns are there to allow LOTS of air to pass, and not a lot of diesel and to indeed allow the pump to backfill with diesel. Then the injection galleries can pick up diesel and send it down the injection lines at high pressure.

Leak off pipes must be in good working order, if these leak out, it will cause problems, particularly in starting, if in doubt, get a foot of leak off pipe and replace them all.

If air can be sucked in on the pickup side, it is possible over night for example, for the injection lines to run back towards the pump and seep into the IP body, this means the first injection or two is incomplete, and will not vaporise properly, which can cause white smoke in the TDI’s.

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At the start of my fuel injection problems I was told by the bloke at the diesel specialists that the pump forced fuel out of the pump and back down the return line at 700BAR. I thought that it was a bit odd at the time but I never questioned it and I have always since believed that to be the case Common sense would have told me that it was wrong because the injectors open at 200 atmospheres (is that correct) which is roughly 202BAR. I stand corrected What a plank.

-Pos

how does oil in the breathers turn to blue smoke?? have had look in top intercooler pipe and there is a little oil in it? Paul