by pass glow plug heating system?

i curently have problems starting 300 tdi first thing. starts fine all day once initally started.
changed glow plugs, glow plug realy but still no power at glowplugs.
checked wiring nothing seems out of place etc.

any suggestions as to where to look now.......

was told today to connect a wire to battery and touch each glow plug in turn for a few seconds, which i did......
the engine started almost straight away....
if i can't find problem with existing curcit i was told to put a wire with fuse and relay straight from the battery to the first glow plug and heat the plugs via a switch for few seconds and bypass the existing system.

whould this work and would this couse any damage else where if i was to do this.

all suggestions welcome.... but would like to sort the existing system first
and only do the bypass if really necessary.

get yer voltmeter out and check that the relay is seeing 12v across the coil and through the contacts - pinouts link below

200Tdi glow plug relay connections - LR4x4 - The Land Rover Forum

hi ya just read message, looked at diagram,
this mornong when i was looking tested the wiring/ relay

on the thick brown wire i was getting 0.52v
thich yellow/black 0v
then the two small contacts were alternating from one 12v to the other when relay clicked and 12v to the other.
cant remember any other voltage readongs from any where else.

even tried old relay in thinking new one may be iffy
any suggestions as im new to diesel engines

you should have 12v across pin 1 and gnd when the ignition is is position 1
you should have 0v on pin 4 when the ignition is in position 1 and 12v when in position 2 (you should also see the glow plug light on the dash)
when the dash light is glowing in position 2 you should see 12v on each glow plug - they are wired in parallel
if the voltages are correct at the relay then check for continuity between the plugs lead and pin 4 on the relay

you can test each plug by taking them out in turn, connecting them to a high current 12v source and making sure they glow red hot within seconds

You have a fuel poblem - nothing to do with your glow plugs.Check your leakoff pipes and all the fuel pipe before the lift pump.

eightinavee said:

You have a fuel poblem - nothing to do with your glow plugs.Check your leakoff pipes and all the fuel pipe before the lift pump.

Click to expand...

oh don't confuse the bloke let him get his plugs a glowing first

Bugger the glow plugs -it wont run without fuel.

shouldnt a tdi start on the button without the need to glow anyway?

eightinavee said:

Bugger the glow plugs -it wont run without fuel.

Click to expand...

so you think he should ignore the fault he knows about "still no power at glowplugs"

and go try to solve an issue where there may not be one ?

that's an interesting approach to fault finding

chris_mack said:

shouldnt a tdi start on the button without the need to glow anyway?

Click to expand...

if it's not fecking freezing and it's got plenty of compression yes

Following this thread with interest as my '97 300TDi auto has developed a similar starting problem but I have power at glow plugs. Lift pump ok, all filters changed 5000km ago. I did have trouble with the sedimenter leaking when I bought the car so maybe it is that playing up but not dripping diesel on the ground. This could be a red herring but I did use throttle body cleaner into the inlet manifold just past the EGR (disconnected) and it seems to be worse after doing that.

Sean said:

so you think he should ignore the fault he knows about "still no power at glowplugs"

and go try to solve an issue where there may not be one ?

that's an interesting approach to fault finding

Click to expand...

Ok - I'll shut up as I know Fu-k all about diesels.

eightinavee said:

Ok - I'll shut up as I know Fu-k all about diesels.

Click to expand...

wont do you any good getting arsey with me

might do.....a sean stress ball......can we flog em on ebay

do i apear stressed ? - i'm quite mellow actually after having spent most of the afternoon pulling an engine out of a S3, and it didnt rain once

Sean said:

wont do you any good getting arsey with me

Click to expand...

Not arsey,just cant be bothered.

For Heaven's sake READ WHAT EIGHTINAVEE SAID!

CharlesY

1994 m reg discovery 300 tdi auto

looking in to the lack of fuel, seems to make more sence at present as being told tdi engine shouldn t need glow plugs unless extreme cold weather conditions.

will look into other problem whilst under the bonnet

alot of guys seen to think the lift pump is the fault.....
how can i make sure the plumger is in the correct position so the pump will pump by hand?

looking to change fuel filter whilst at it......any tips

all suggestions welcome

when changin the filter, dont hit the gas immediately after restarting!

i did this with my TD, it restarted fine after changin the filter, then I blipped the throttle as i always do to make the battery warning light go out (its a TD thing, I think), and it killed it.

was a right bugger to get started again!

thanks for that, any thing else to watch for......
any tips on making sure plunger not engaged on an auto?

whats wrong if it starts whilst holding accelerator pedal to the floor?
changed the leak off pipes, starting better but just keeps turning without starting if don't hold pedal down