high pressure fuel pump regulator possible issue after change

After advice received a while back I changed the high pressure fuel regulator seals. I was test running the vehicle after doing this but almost immediately one of the brake pipe hoses split (now repaired). It has been off the road since then because I'm also changing the vci carrier bearings. I started it up again this morning and still had the clouds of white smoke I assumed previously were unburned fuel from before I changed the regulator seals. Left it running for a while and smoke cleared. However, when revving the engine I get clouds of white smoke.

From reading previous threads it looks as if this might be the HP pump spraying fuel into the crankcase. There is no lumpy tick over and it revs smoothly. Is it possible that when I changed the pressure regulator seals I got it wrong somehow and would faulty seals in the regulator produce this spraying of fuel I've read about?

Asking because I don't mind ordering in a complete new regulator (rather than change seals again) but I am not minded to replace the fuel pump itself. I'm more minded to retire the car and use for spares.

I should say I would be taking the car out for a bit of Italian tuning to see if it cleared the smoke BUT I read this problem with the spraying of diesel can cause over run, and that's not something I want to have to deal with.

edit: I have also been reseating injectors. I guess I will have to do a leak back test to be sure, but I would have expected lumpy tick over with failing injectors.

Are you sure it's smoke and not steam? It's not uncommon to see quite a lot of steam on an engine that hasn't been run for a while when it's very cold outside. A cold exhaust can cause water vapour to condense into lots of steam, which looks like white smoke.

Nodge68 said:

Are you sure it's smoke and not steam? It's not uncommon to see quite a lot of steam on an engine that hasn't been run for a while when it's very cold outside. A cold exhaust can cause water vapour to condense into lots of steam, which looks like white smoke.

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I'm not that lucky. You be the judge: let it tick over for a good 20 mins before getting in and revving it. Smoke only pours out when revving, soon as I go back to idle it stops, or reduces to barely there. Wouldn't I be getting steam at idle too?

I do remember when I put the fuel pressure regulator back on after doing the seals it was a very tight fit. Didn't quite feel right, if you know what I mean, even if the bolts did do up tight. I can't work out what the symptoms would be if the valve were stuck open or stuck closed. I know it is a solenoid and I know they can fail, but I can't quite think my way into what failure would do to the fuel flow.

There is one other thing I forgot to mention: although the idle and rev is smooth, it is not boosting strongly. Not lumpy, just feels slightly underpowered. Now is suppose that might go with not enough fuel being delivered when revving and if the pressure isn't there in the system maybe that is causing low pressure through the injector and not enabling proper atomisation. But that's just a hunch to explain what wold happen if the regulator is stuck (open or closed, can't work out which) and not allowing an increase in fuel flow when it is demanded..

If it was steam, I'd expect it to clear as the engine warmed the exhaust, so it does sound like a mis-fueling injector. Odd it runs smoothly though, as a bad injector would cause a misfire.

Nodge68 said:

If it was steam, I'd expect it to clear as the engine warmed the exhaust, so it does sound like a mis-fueling injector. Odd it runs smoothly though, as a bad injector would cause a misfire.

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Yes, I figured the same. On an old thread Andy (freelance) talked about a high pressure pump seal going and causing excess fuel to be carried through the system. Same old problem really - don't want to swap out parts only to find the last thing I check is where the fault is. I think I am going to have to master the business of taking voltage readings to diagnose faults. There's plenty of you tube videos about it.