300tdi still having starting issues!

Hi again

I started a thread on this some time back, my 300tdi refuses to start every single morning.

Fuel seemed the obvious issue, or more the ingress of air into the fuel system overnight. She will turn over strongly, but just not fire. If I squirt some easystart into the airbox, she fires immediately, does not splutter or cough, and will run smooth immediately, and give no more problems all day, and then leave overnight, no start.

So far I have removed the sedimentor, replaced the fuel filter, replaced the lift pump, replaced the leak off pipes(they were goosed), replaced the fuel pipe from tank to lift pump/pump to filter/filter to injector pump and injector pump to leak ff pipes... none of this seems to have worked, oh and I fitted a one way valve between the fuel filter and the injector pump

She runs sweet as soon as she fires, and never misses a beat after this, but I am starting to run out of options here. I have tried starting her with jump leads as well, to ensure plenty of power, and discount battery, but she just cranks the same, until the 1 second burst of easystart needed to fire her up

Can anyone help??

Main culprit for this is rusted pipes on fuel sender under boot floor. Check that and de rust thrn cake metal pipe ends in sikaflex. If that solves it you need a new sender.
Injectors could be playing up? Maybe try spare set off another 300? Filter bleed screw in ok? Fuel filter housing in general ok?

Cheers for that..

I have bunged up the steel with silicone sealant, and then replaced the pipe from the tank to the pump, so was hoping I have eliminated this... I think the rest of which you mentioned is OK, however have not tested the injectors, I hoped having the one way valve inserted would hold diesel in the system so she would have enough fuel there to fire her up, but has not worked, making me think I am on the wrong track with fuel problems?

Whatever it is, I am seriously fed up with her right now lol

when cold, check to make sure it's fuel.

try manually priming the lift pump as much as you can and see if it fires better.

also another time, slacken off the inj nuts and have someone crank her when you see how much fuel comes out. see if it gets better after a few cranks to confirm.

any air in the fuel filter via the bleed screw?

Cheers for that... will try these next.. still have to replace fuel stop solenoid, just in case. .

Did you do the leak off pipes between the injectors and although you have replaced over leak off pipework is it all sealed nicely? Lots of air can pass through a space than no diesel may leak from or only just weep. First culprit with poor starting fuel related issues on 300tdi's is almost always the 50p worth of leak off pipe.

Also, if you deck the throttle and then start it does that speed it up a bit or even fix it?

discomania said:

Did you do the leak off pipes between the injectors and although you have replaced over leak off pipework is it all sealed nicely? Lots of air can pass through a space than no diesel may leak from or only just weep. First culprit with poor starting fuel related issues on 300tdi's is almost always the 50p worth of leak off pipe.

Also, if you deck the throttle and then start it does that speed it up a bit or even fix it?

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mine seems to kill them every 4-6 months.. tried two different types now. might try normal rubber hose next.

might have had a bit of veg in though :bowl:

Get yourself some Viton hose.

http://www.par-group.co.uk/hose-and-ducting/flexible-tubing/6709-viton-rubber-tubing/

discomania said:

Get yourself some Viton hose.

6709 - Viton Rubber Tubing | Flexible Tubing | Hose & Ducting | PAR Group

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i think normal r9 fuel hose has an inner viton lining doesn't it?

trax said:

i think normal r9 fuel hose has an inner viton lining doesn't it?

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Not sure about inner lining but it is Nitrile rubber.

Cheers folks.. I have more tubing so will re do the leak offs again, just to be sure! She had sat for about 4 hours this afternoon and had to crank her over for a good 30 seconds, which has not happened before so might be getting worse.. will have to keep an eye in it.

SenseiLeon said:

Cheers folks.. I have more tubing so will re do the leak offs again, just to be sure! She had sat for about 4 hours this afternoon and had to crank her over for a good 30 seconds, which has not happened before so might be getting worse.. will have to keep an eye in it.

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Yeah thats a long time. Im no expert but mine when left just cranks for a second as opposed to immediately starting if its not been left. I think that is an air leak. So stop solenoid sounds reasonable to me or injection pump stuff.

yes, 30 secs is a lot, i thought you meant 3-5

check voltage at fuel solenoid also if you still have the spider leccy iimmob connected. that can balls right up.

get some wire and connect one side to the bat, the other to the fuel solenoid and see if it cranks first time. that bypasses the electrickery.

yeah, it will crank almost forever in the morning before firing, the only reason I had stayed away from the solenoid before now, is the fact that she starts good when warm, so always put it down to fuel...( and the fact that first time it happened, the AA man used easy start and jumped it, and told me probably air in fuel lines, hence I got the idea!)

However, I had a quick try sticking a lead direct from batter to top of solenoid.. it feels a bit 'sticky', ie it just did not click as posotive as i would like, then after a couple of goes, it sounds like it is buzzing, or clicking several times a second.. do you reckon this may cause starting issues? maybe once engine has warmed, it moves a bit more freely?
I have a new solenoid in the shed, I am just struggling to find a way to get the old one out!

thanks for your patience folks

I'd recommend swapping it if for nothing more than peace of mind, I've just done an engine swap in my tratter for a 300tdi and I can start that first turn of the key without using glow plugs and it will catch straight away

have you tried the glowplugs and relay taken that it only happens when cold bud?

I have had this same cold starting problem and it was the throttle shaft seal in top of the Bosch VE injection pump. If this seal is leaking, (sucking air), it allows the fuel in the top, (inlet), chamber of the pump to drain back to the tank via the return fuel line when the engine is not running, thus little or low fuel prime to the injector elements for that first start of the day. The problem is time based, the longer the vehicle stands the more likely it is to be a hard start.
To test, make sure the fuel tank is more than half full and overnight park the Disco nose downhill as steep as possible, if this seal is the problem the engine should start straight up cold no worries after being parked this way, conversely if you park on the level to nose uphill position you will find it will persist with no start straight away after standing overnight.
The pump throttle shaft seal is cheap and easy to replace.

Gazbo said:

I have had this same cold starting problem and it was the throttle shaft seal in top of the Bosch VE injection pump. If this seal is leaking, (sucking air), it allows the fuel in the top, (inlet), chamber of the pump to drain back to the tank via the return fuel line when the engine is not running, thus little or low fuel prime to the injector elements for that first start of the day. The problem is time based, the longer the vehicle stands the more likely it is to be a hard start.
To test, make sure the fuel tank is more than half full and overnight park the Disco nose downhill as steep as possible, if this seal is the problem the engine should start straight up cold no worries after being parked this way, conversely if you park on the level to nose uphill position you will find it will persist with no start straight away after standing overnight.
The pump throttle shaft seal is cheap and easy to replace.

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that'll work for all leaks.. not highlight the seal

trax said:

that'll work for all leaks.. not highlight the seal

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cool... that might be the way forward then, just carry a set of ramps with me, and reverse her onto them at night, save all this hassle :clap2:

SenseiLeon said:

cool... that might be the way forward then, just carry a set of ramps with me, and reverse her onto them at night, save all this hassle :clap2:

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haha, an electric pump to prime the system would work too.. but not needed if it's all working properly

i think the solenoid sounds likely, with all that cranking i would have thought it would have primed much earlier. gl