zx td NR valve

[8304]

My zx runs very roughly upon first start up in mornings - i think its beacuse fuel is draining back to the tank overnight.........

I fited a non return valve to the supply to the pump today - will be interesting to see how the car starts in the morning.....

ill keep you posted 8)

alastair

[sooty]

I would suspect a heater plug or two has failed.

The same thing happened with mine and found a duff heater plug. Ok now, starts and runs sweet as can be, even on really cold frosty mornings.

If the fuel ran back to the tank, I think you would have a bad time starting her.

My Sons 306 td with a Bosch system had perished fuel return pipes between the injectors and air was getting in and the fuel ran back to the tank. It was a pig to start, now all the fuel return pipes are renewed, it starts ok. This does not apply to the Lucas/CAV systems for some reason.

Check your heater plugs.

[AndersDK]

If you can pump the bulb on the filter unit - then fuel is draining back to the tank.

[lighteninguk]

by the looks of the lads profile... he's a petrol lad....

[AndersDK]

by the looks of the lads profile... he's a petrol lad....

Naaahh...

As I read it :

Zxtd Aura converted from 1.8i Petrol - Lowered, 20psi boost extra fuel - weeeeeee!

Then he converted from petrol to diesel - i.e. replacing the motorzzz... 8)

[8304]

Hello people,

Thanks for your responses...

Well done anders, i am indeed a diesel head - the car has the td lump in it now as i converted it from 1.8i after crashing my original td zx, engine and gearbox with front subframe was changed, fuel system changed including tank, exhaust swapped and under dash and engine bay wiring looms swapped along with the smaller items like radiator and the whole of the interior becuase the original was blue which i didnt like....

The car has had two new sets of glow plugs, initially some cheapo ones and when that didnt work some NGK's which are meant to be a good brand i think... - the glow plug relay s working because the interior light goes brighter 20 seconds after light going out.

The leak off pipes from the injectors have been replaced (bosch system you see) along with all under-bonnet flow and return pipes from the pump - right back to the metal ones under the car.........

But it still runs poorly on start up - lots of white smoke it must be air in the system and the only way i can see that happening is if the fuel is draining back to the tank overnight.

Sooty, the car starts on the button and runs smoothly for about 5 seconds before going lumpy and smoky, i think it is starting on residual fuel left in the diesel pump and 5 seconds later or so sucking through some of the air in the fuel line....

Is it possible for air to get in around a faulty seal under the throttle lever on top of thre pump??????

Any ideas - im well chuffed with the car but long for it to run properly on cold mornings

cheers

alastair

[sooty]

Have you drained any water from the fuel filter lately, this could collect overnight and seperate, then when you start it maybe picking this up, giving the white smoke.

The other thing have you tried as suggested by Anders, to pump the bulb in the fuel line to be sure you have plenty of fuel at the pump.

Also when it starts does your tick over, run about 900/1000 rpm. If the tick over is at normal approx 800/850, then your cold start system needs looking at.

NGK, I have always found them to be good, but its still worth checking them to be sure. No need to remove them just remove the inter-connecting cable, get a Headlamp bulb with some wire, one end on the + of the battery and the other on the thread of the plug. If it lights up, the plug is OK, if not its duff.

Good luck