How long should glow plugs be on for?

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
P

P38 Phil

New Member
Posts
23
Location
Clacton on Sea, Essex
Hello All,

Just a quick one. I fitted new glow plugs two weeks ago (delphi ones so not cheapos) as I had issues starting from cold. She know fires up but a bit lumpy for a few seconds, then runs fine. If I turn the ignition on and let the light go and and repeat again before starting then she fires up perfectly, which leads me to think that my glow plugs aren't on for long enough. I've timed the light and it stays on for about 5 seconds but is this normal? I've seen loads of new glow plug timers for sale and wondered if this a common issue?

Cheers,
Phil
 
The time glowplugs stay on is a function of engine temperature, maybe the temp sensor is on the blink. On cold mornings mine stay on for, I would guess, near to 30 seconds.
 
I'm not 100% sure but I think the glowplugs stay on after the light has gone out, is this correct?

Data, my light has never stayed on for anything like that long, even when around 0 degC - are you talking about how long the relay is energised for, or how long the light on the dashboard stays on?

Cheers,

Jerry
 
Thanks Datatek. I certainly have never seen my light stay on for anything over 5 seconds regardless whether it's -2 or 20 degrees outside. I'll have a look into it and see what I can find out. Both my external temperature and engine temp sensors both seem to function correctly but it's a starting point I guess.
 
A simple multimeter should do it - from memory when I was trying to sort out my own starting problems, my wife turned the ignition on and I measured the voltage on the glow plugs which stayed up at around 11V even after the light went out, not sure for how long for though. Even so, it should fire up fine once the light has gone out, does sound as though something isn't quite right with yours atm......you could try counting an extra 5-6 seconds after light goes out and cranking it then, to see if that makes any difference.....

Cheers

Jerry



Cheers,

Jerry
 
Thanks Jerry, I'll give that a go sometime tomorrow. The advantage of my scope is that it has an inbuilt trend plotter so I can set it up to record and time the voltage, so don't require the wife! lol
 
I checked mine and the light is on for 5 secs, did you test the glowplugs before you fitted them, just because they are new does not mean one can't be duff.
Davie
 
jerrytlr said:
I'm not 100% sure but I think the glowplugs stay on after the light has gone out, is this correct?

Data, my light has never stayed on for anything like that long, even when around 0 degC - are you talking about how long the relay is energised for, or how long the light on the dashboard stays on?

Cheers,

Jerry
Click to expand...

The glowplugs should stay on during cranking as far as I'm aware but I haven't checked it on the P38, the light just indicates the pre-heat time.
I'll have to check the time the light stays on, when it's -10C and the car hasn't been used for a week it seems to take forever to go out. The car is an instant starter hot or cold:D
 
You must log in or register to reply here.

Similar threads

L
Sport Glow plug light
Replies
6
Views
1K
lj5000
L
T
Testing and changing the glow plugs on a TD5
Replies
11
Views
2K
Twinnie
T
Mr K
Freelander 1 Glow Plugs test results and replacement
Replies
11
Views
2K
Arctic2
Arctic2
twilly
Jumping Glow Plugs?
2
Replies
21
Views
3K
jimleshed
J
cappers
3.5 hotwire efi won't start - solved, poor connection to coil -ve!
Replies
14
Views
3K
AllanWorms
AllanWorms
Back
Top