Poor starting 300tdi

Earth strap is on the exhaust side of the engine, below all the pipework, back of the starter housing, going to the chassis below the airbox! Well, it is on mine ... ;)

Possibly easier to get to from underneath.

Best way to start from cold I found is to let the heater run, turn off and let it run again, then with foot flat on throttle and clutch in, startup. Let revs build a tad before they get too much and off throttle.

In message , "Davy Murray @Blueyonder" writes

Presumably you've found and checked the battery earth?

Dismantle/Check/clean all high current connections, both earth-side and positive, if you haven't already done so.

As a quick check connect a jump lead directly between the battery negative terminal and a good earth point on the engine. That will bypass all the earth-side connections, hopefully give you more cranking speed and cheer you up a bit! Starting easily with a jump start if connected directly to the engine block suggests poor earth-side connections. Or the slave battery could be in better health/higher capacity than your own.

I certainly found that a double dose of the heater plugs as suggested did help.

It would also be worth checking that you do have volts at your new heater plugs when the key's in the 'run' position.

If all this fails do you have a good connection between the starter body and the engine block?

This one's an auto!!

It shouldn't be necessary to floor the throttle. The pump should give you maximum fuel regardless. But if all else fails .....

oops, must have skipped that bit .. ;)

I know, but it is what LR say in the handbook and when I tried it, it worked!

Isn't there some sort of timing relay on 300Tdi on the glow plug circuit? ISTR it being mentioned in here b4

Or after struggling to start a quick feel of battery terminals, along the high current cables/straps and all high current joints will find any that are a bit iffy. Iffy places will warm if not hot...

That's a quick way to wreck an engine! Lots of rev's before the oil gets round, also the turbo wont like it, lack of oil again.

Dave B.

Check the alternator wiring, and "goodness" of all the connections. Check it's charging too. Should get just over 14V at the battery when it's been charging for 30 seconds or so.

Dave B.

Yes, there is a black multi plug "relay" thing, stuck to the bulkhead. They do fail.

There are at least two timers in there. The main one for the plugs works the big relay, and the plugs. That comes on every time you start the thing, hot or cold. There is a temperature sensor that will make it a longer time, when cold. (Atmosphere, not engine temp.)

There is a shorter timer that works the warning light.

When the light goes out, the plugs should still be powered, for about the same time again.

Wire a second temporary lamp to the glow plugs to see if they are getting power. There will be a total of over 80A for all 4, when they are on, so good condition wires and connectors are needed.

Have Fun.

Dave B.

You misunderstand, when the engine starts it's a tad lumpy, so build revs (I should have said to maybe 2k only) and as I said, come off before they get too much. I never actually said lots of revs and didn't mean it to be read that way.

If you come off throttle immediately it fires and without a few revs on it can stall easily and be a right bugger to start again ... ;)

Hi. My '96 300tdi auto is giving problems on colder mornings. If it doesn't start on the first couple of tries, the battery gives up and it won't start. I replaced the battery last year and fitted another one last week. It is still not starting on cold mornings. The car starts easily from a jump start. I replaced the glow plugs last weekend. I am now trying to work out what else to try. I haven't come across an engine earth on my work so far - I haven't made an exhaustive search. Any clue as to where to look from those more in the know than myself would be apperciated. Thanks Davy M

Just because the light on the dash lights up, don't assume the glow plugs are working. Check the (big) fuse - mine was gone when I bought it - didn't find out until the first winter. Once fixed, the 300tdi was never a problem to start, even when it reached high mileage. Joskin

Thanks for the advice everyone. Replaced the engine earth strap and problem solved - started instantly after glow plug warning light extinguished. Cheers Davy M.