Lupo TDI: Extend Glow Plug Time for Better Start

hi,
'Does anyone have an idea on how I can extend the glow plug duration in my Lupo 1.4 TDI so that it afterglows?'


Regards,

Björn.

The easiest way is to manipulate the signal from the coolant temperature sensor.
However, this also increases the initial amount of fuel injected during startup, which can lead to the well-known "revving up."

Regards,
Alex.

It's still glowing! How long do you want it to continue glowing?

Currently, it glows for 180 seconds after the engine starts, and the afterglow period ends either after 180 seconds or when the engine is revved above 2500 RPM.

Regards,

Manuel.

Does this mean that if the 180 seconds have not yet elapsed and I am rotating at over 2500 RPM, the afterglow will stop? Or does it continue to glow even when I slow down below 2500 RPM?
I'm interested in this because I'm currently converting my Lupo to run on LPG (single tank), and I want to make it as easy as possible for the engine to start and warm up.


Regards,

Björn.

That won't make any difference, whether you preheat or postheat it.

The fuel MUST be preheated before entering the injection system; some systems even use inductive heaters for the pumps.
The glow plug only plays its part in starting the engine or during the initial warm-up phase for engine operation. It doesn't make the engine warm up any faster.

CU Gremlin.

Yes, and excessive afterglow puts unnecessary strain on the electrical circuit, and the spark plugs wear out too quickly. If you go overboard, it can even cause cylinder head damage because the heat is distributed very unevenly.
It's better to pre-warm the fuel externally; that makes a significantly bigger difference.

I'm preheating the biofuel using a coolant-to-water heat exchanger (A8 fuel cooler) and, during startup, electrically via two glow plugs... I'm mainly concerned with starting the engine on biofuel, but I think that if the Lupo already has an afterglow time of 180 seconds, it should be sufficient because by then, the electric heater will have already brought the biofuel up to temperature.


Best regards,

Björn.