Perfect startup/tick over, then on the road short period of white steamy smoke, help?

[ChrisAndEmma]

Sorry - wax motor action described back to front! Should be expanding wax on melting pushing against a return spring. This means default setting for the a cold pump is ”timing advanced”:

”
When the heat source is energized, the wax block is heated and it expands, driving the plunger outwards by volume displacement. When the heat source is removed, the wax block contracts as it cools and the wax solidifies. For the plunger to withdraw, a biasing force is usually required to overcome the mechanical resistance of seals that contain the liquid wax. The biasing force is typically 20% to 30% of the operating force and often provided by a mechanical spring or gravity-fed dead weight applied externally into the wax motor (Duerig 1990, p. 214).
“

Wax motor - Wikipedia

en.wikipedia.org

 

[ChrisAndEmma]

Update 2 - ok, so all back together now after taking the wax motor and sprung push rod assembly off the van for bench testing.

Bench test with 12V supply showed assembly max temp of 52degC vs indoor temp 19degC after approx 7m20sec. Max stroke of assembly approx 6mm.

On van, wax motor still cold after approx 5 min idling warm up but hand hot after 10 min run, so I need to figure out the temp switches’ crossover threshold.

The van runs like a dream now - no white smoke and very little dry soot on the exhaust after a 30 min run. Stroke needs adjusting in situ as there is a bit of unused advance at cold but van started fine even so. Flame heater still disconnected pending a new ignition glow plug.

If anyone knows where I can find the controlling relays for the flame heater glow plug and fuel supply solenoid, I’d be grateful. Also I’m guessing there must be a relay for the wax motor supply and I’m wondering if there is an ambient temperature sensor somewhere to tell the cold start systems when they are needed? Thanks in advance for any tips!

 

[ChrisAndEmma]

Update 3 - in case anybody treads this Fiat Ducato 2.8 idTD cold start trail in future:

1) The flame starter glow plug and its fuel supply solenoid are under the control of the Bitron 2044029 unit mounted under the scuttle above the battery. This has an onboard solid state temperature sensor which determines when to acitivate the flame start sequence.
2) The Bosch VE wax motor which retards this injection back to standard from advanced once the engine is warmed up is wired in series with the thermoswitch mounted on the back of the thermostat housing assembly. The sensor mounted on the front of that assembly supplies the dashboard temperature guage.
3) The 3 wire lower right corner mounted radiator temperature sender is a twin thermoswitch which grounds the fan relays. It switches at two different temps:
a) on first switch closing it controls a relay to fan 1 taking the ballast resistor out of circuit, hence changing from slow speed to standard.
b) on second switch closing a second relay energises fan 2 at standard speed.
4) Last remaining item to confirm is the glow plug spec compatible with the Bitron unit - two appear to be available a 20A 12V and a 29A 11V. I’m guessing that the 29A is intended for colder operation but will investigate.
5) Beware wiring diagrams, even from Fiat publications - I’ve not found any that are consistent with my van.

At some point, I’ll write this up with pics, part refs and links etc for future info. All the info has been gleaned from the web and double checked on my van, which as far as I can tell, retains the standard wiring of the time.

 

[The Old Man]

Ok here goes, the base vehicle is a 1995 Peugeot Boxer Swift Kon-Tiki, 2.5TD with 55k on the clock.

Had our elderly moho out last friday, hadn't been used for a couple of weeks.
Started instantly, tick over was perfect too.

Got her out onto the road to set off & had sudden plumes of white steamy smoke with a loss of power.
This steam evaporated very quickly in the air so my thoughts are that it was steam rather than unburnt diesel.
My first thoughts were head gasket, checked the oil & water, all was well.
I then checked to see if water had got into the (new) air cleaner & it was bone dry.
She started up instantly but, was still showing steam in the exhaust & a bit spluttery, brought her back to the house & investigated further but, could find nothing wrong.
Reversing out of our drive which sadly is easiest means reversing steeply downhill, then levelling out as she gets to the road.
The weather in her layup time had been torrential rain for quite a few days.

So started her up & the steam was gone, running normally, took her for a short run to make sure & she ran perfectly!
Set off & she drove totally normally.

Now the only thing which was different to normal is that when she was parked up, she'd been tilted over to the drivers side & slightly bum down.
Is there any known way for water to enter the inlet side of these engines on these particular vehicles?

I did have a similar problem on our old Peugeot Boxer Autosleeper on MOT day off all days, this cleared very quickly too & it never happened again.

TIA....Robert.

I know nothing of mechanics but a fellow customer at Starbcks has an Adria Twin, which he took for a run at the weekend after a few weeks inactivity and he described similar results. The AA diagnosed water in the fuel from condensation and possible seepage from the recent heavy rains in through the fuel filler cap.

Fuel drained, fresh fuel and he was on his way.