300tdi Starting problem

mark g · Feb 6, 2011

Have a weird starting problem with my 300 tdi.
When I turn the ignition switch there is a delay and a struggle to start as if its got a flat battery, then it will burst into life. It has never not started but a few times its felt like it ain't gonna.
I have checked the battery and alternator with a voltmeter and they are fine. I have checked/cleaned the battery/chassis earth straps, checked/cleaned the bulkhead earth, checked/cleaned the starter motor connections, removed the start relay from fusebox and it still started without this in place, not sure if that correct.
Have had the dash in and out a few times to fit a rev counter, could I have dislodged someting here? I did check the ignition switch connection tho and they all seem fine.
At a bit of a loss where to look next.

Mark,

pussyeater · Feb 6, 2011

mark g said:
Have a weird starting problem with my 300 tdi.
When I turn the ignition switch there is a delay and a struggle to start as if its got a flat battery, then it will burst into life. It has never not started but a few times its felt like it ain't gonna.
I have checked the battery and alternator with a voltmeter and they are fine. I have checked/cleaned the battery/chassis earth straps, checked/cleaned the bulkhead earth, checked/cleaned the starter motor connections, removed the start relay from fusebox and it still started without this in place, not sure if that correct.
Have had the dash in and out a few times to fit a rev counter, could I have dislodged someting here? I did check the ignition switch connection tho and they all seem fine.
At a bit of a loss where to look next.

Mark,

sounds a bit strange that it starts without the starter relay, it shouldn't do this. Are you sure you removed the starter relay or has someone bypassed it?

paul_c · Feb 6, 2011

I think you've removed the wrong relay.

Sounds like a sticky starter solenoid.

ratty · Feb 6, 2011

What year is the fender? As already stated it sounds like either the starter relay has been bypassed or you pulled the wrong relay.

Shifty1962 · Feb 6, 2011

My mates Disco showed the same symptoms. We changed the battery, alternator, starter, earth straps and it still played up. It turned out to be the ignition switch. Fitted a new one and its never struggled to start since. Might help.

ANGELO DAMATO · Feb 6, 2011

I'll go along with the lads above, by the way how old is your Battery? if you put a volt meter on the pols as you crank it what is your reading?

mark g · Feb 7, 2011

Its a 97 300tdi. Ok, maybe I removed the wrong relay It was as indicated on the inside cover of the fuse box, will check it again to make sure.
Battery is a red top Optima about 4 years old, tested the battery with engine running and under load (lights/heater on) and it was giving the correct readings so alternator is charging and the battery does not seem lose its charge.

tottot · Feb 7, 2011

To check if ignition switch is at fault connect a wire to starter solonoid and touch other end on battery[make shure landy is out of gear and wire can not catch on any rotating parts]If still the same suspect starter motor problem.

ratty · Feb 7, 2011

tottot said:
To check if ignition switch is at fault connect a wire to starter solonoid and touch other end on battery[make shure landy is out of gear and wire can not catch on any rotating parts]If still the same suspect starter motor problem.

That won't test the switch. It will still leave the possible cause as being immobiliser, ignition switch, ignition relay, broken or corroded starter fly lead.

Ideally he needs to hold a power probe or test lamp to the actual fly lead connector on the starter motor. The power probe should show green (earth) while the ignition is in the off, first and second positions. It should then turn red (live) when the ignition switch is turned to the third posiition (the crank position). If the led fails to turn red the process shold be repeated with the end of the power probe stabbed through the insulationof the fly lead that goes to the starter motor and in a position close to the starter motor connector. If the led turns red now then it is just a connector fault. If the light again remains green then no power is reaching the lead. Investigations can then move up the line to the ignition switch and relay.

discomania · Feb 7, 2011

Lazy starter, I've had one on my Disco, it was terrible. Starter from the Defender - whooomph.

300tdi Starting problem

mark g

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pussyeater

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paul_c

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ratty

I'm not special I'm limited edition

Shifty1962

Well-Known Member

ANGELO DAMATO

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mark g

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tottot

Well-Known Member

ratty

I'm not special I'm limited edition

discomania

Well-Known Member

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