Low power on 1.9D ZX for first mile or so...

[RussellF97]

Hi All,

1995 ZX 1.9D with Lucas pump.

When first starting after a cold night, it seems a bit down on power until I've gone about a mile or so then you can feel it pick up; it's almost as if one injector isn't working although it idles OK after starting. It will only do this after the first start of the day and the rest of the time it's fine.
Last weekend I went down to the Charente (about 700 miles round trip) with no probs - and 55.6 mpg, which I'm happy enough with! so it wouldn't seem there's too much wrong with it.

I'm just curious as to what it might be. Any thoughts anyone...

Phil

[spider]

Smooth idle and no excess smoke on cold start ?

It does sound odd, I'm sort of leaning towards valve clearances (although I'd expect that to cause a starting problem) as they will change when cold / hot.

I can't see it being an injector issue (I could be wrong) as I'd expect it to have the fault all the time if it was, they can 'dribble' but that would cause smoking if nothing else.

It is worth cleaning the fuel filter housing out / change filter if in doubt as to when it was last done, blocked fuel filter = low power, blocked air filter = black smoke, perhaps there's something restricting the fuel piping that improves once its been around a few times, if that makes sense.

A (very gentle or you will blow something like a clip off or burst the pipe) air line down the return line from the bulkhead area back to the tank may help too, I think a restriction in the return could cause something like this, certainly a feed restriction could. I guess I'm thinking of that growth / sludge type stuff that can build up in diesel but I do not recall seeing any myself for a long time.

EDIT... I thought about the sold start advance solenoid wired to the fast idle cable when stone cold too, but that would not really slow it down, if anything I think it would make it slightly more lively if that was stuck on (very rare for the solenoid itself to jam I think)

[RussellF97]

Yep, it idles OK and doesn't smoke when starting. I had the injectors serviced 5000 miles ago, and before that I checked the tank strainer was clear. The fuel filter was changed in Feb (8000 miles ago) when I did the head gasket.
However, it seems to be OK now, so I'll probably never know...! Perhaps it was just the first fill-up after I came back this side of the Channel. Thanks for your reply anyway...

[spider]

Ah you've done the likely causes then.

Not sure what to suggest off hand although if its OK now then perhaps we will never know.

[citronut]

i was thinking maybe the was stat not functioning,

your not using cooking oil are you,

[spider]

i was thinking maybe the was stat not functioning,

your not using cooking oil are you,

Good point, I did think about that a bit but as far as I'm aware that would just cause very slow stone cold idle and a dependency to stall on deceleration. I thought about the microswitch on the end of the cable to push the timing a bit too but that would make it slightly more lively I would of thought as it would be a fraction advanced. I could be wrong.

Mine stuck on a few years on the 205TD so I threw it out and fitted a NA blank, it was fine after that although to be fair it ran well with it jammed on too if a slight 'crackle' from it being a bit too advanced when it was jammed on

Good point about the veggie oil though. I guess that would really upset it if its not hot enough.

[RussellF97]

It's running on 'heavy oil' - I'm told Lucas pumps don't like veg oil. I get the fast idle until it warms up OK.

I don't understand the bit about a microswitch. Mine dates from before they started festooning the pump with electrical gubbins.

[spider]

You may not have one, I think only the later NA units had them or most of the Turbo's. It is safe to disregard my post above about that.

Malcolm was just wanting to make sure you were not running it on veg oil or suchlike instead of regular diesel fuel.