TD4 Turns over, but doesn't bite

Hi,

I have read a few posts here, which explain their TD4 engine is turning over and not biting, Mine is suffering the same, but if i connect to my other car using jump leads, it typically fires within seconds.

When the car is running, it runs fairly well, although it has to be said that when it first starts the accelerator can be slightly slow to respond, but as i said, once on the move, the car is fine.

I was thinking that my first port of call could be to check the crankshaft position sensor...although having checked online, i think these can cost around £60...does anybody have any ideas or advice on this? If the injectors or High pressure pump were faulty, would the engine run at all?

Thanks for your help guys!

Neil

Hi Neil,

Can I suggest that you check all the simpler fixes before you think of starting to try this or that sensor.

If it starts easier using jump-leads I would question whether the battery is up to scratch.

Try a volt meter across it with the ignition off, then with the ignition on, and again after the engine has been running for a few minutes.

This will check the condition of the battery and the output from the alternator.

Do you do lots of short journeys? - that would run down the battery. Is it the original battery/ Is it the correct rating of a battery? If its not at least 80amp/hr it will not be man enough for these cold mornings.

Hi Singvogel,

Thanks for your prompt reply...I have just replaced the battery with a brand new Bosch one...so now the engine turns over much quicker than before, but still struggles to bite. Although after a decent trip for shopping for example, it will bite...eventually... when restarting and turning over for about ten seconds.

I hope somebody can help with this as the other half is getting anxious that it will let her down when trying to get to work in the morning.

Right, we need more info.

OK, so its a TD4.

What year, what mileage, when were the air filter and fuel filter changed last?

Whenit is running is there any smoke? if so what colour.

Equally difficult hot or cold?

Can you hear the fuel pump/s running when you first switch on, before you key the starter?

Hi again... your time is much appreciated!

td4 2004 95,500miles on the clock. we bought it in september from a vauxhall dealer, who advised me they performed and oil and filter change prior to us collecting it. we have already had it back to the dealer and they replaced the fuel pressure regulator and an associated wiring loom.

yes i can hear a pump priming behind the drivers seat when the ignition is live. there is no smoke to mention when it is running, although after the time it takes to start, there is a cloud of smoke when it does fire, but this clears.

I am just confused as it starts more or less straight away when it is connected to another running vehicle, hence my initial thought of a sensor, which is pressumably activated with a slightly higher voltage than the standard 12v of the battery trying to start the car?

it can also take time to start warm, maybe 5-10seconds of turning over, before firing.

what is the ampage of the new battery?

Sounds to me like a possible siezed injector.

Checkout the injector leakback test.


Reasoning : An injector leaking back will reduce the fuel pressure present when cranking, you connect it to a running car. This brings the battery voltage up from 12.6v to 14.2v, it allows the engine to crank faster, thus turning the HP pump slightly faster, allowing the start. It might also explain why it requires a bit of cranking before start, to let the fuel pressure build slightly.



Obviously im just guessing though

vissie, thanks for your advice...it makes sense, and if i am honest was news i probably didnt want to hear...however would this still be the likely reason even though the engine does restart....albeit eventually...after a longer run / whilst engine is warmer?

my money is on faulty injector, leak back test will show either way. looking for one (or more) injector leaking back a radically different amount of diesel.

Could it be the glow plugs? Or maybe Circutry causing not enough power to the plugs when the engine is cranking over?

Thanks guys! Booked car into a LR specialist in Preston for Diagnosis test. I really hope it isn't injectors, but what will be will be...

I'll repost when we have some form of answer...

Bujt again...a massive thanks to everyone for your input.

jedi said:

Could it be the glow plugs? Or maybe Circutry causing not enough power to the plugs when the engine is cranking over?

Click to expand...

nah glow plugs only kick in below 5 degrees, as optimus says more than likley an injector on it's way. If left canking time will only increase.

I'm not sure of the best place to get replacement injectors from, if that is the issue its found out to be by a garage. Keep in mind your options about getting them reconned though.

Thanks again...its going to garage tomorrow, strange thing is I have used it this morning, its been snowing here over night, so thought i'd give it a go to get to the railway station. used spare key this time, it cranked for around 20 seconds then fired and ran fine down to the station...on my return to the car this evening, it cranked for 15-20seconds, then fired again....came home, then switched off...my partner is taking it to work on her night shift, then the garage tomorrow morning, but again with spare key it cranked for 15seconds or so, then fired...really confused,

could the key chip be the issue? albeit intermittent?

i realise that 20 seconds is still a long time to crank the engine. also maybe worth mentioning that when ignition is on i can hear the pump as mentioned earlier (electronic pump sound / whirring), but when the car is running the sound is more of a "gurgg-u-guurgg-a-gurg" sound...sorry for the sound effects.

Would this still point towards injectors? dont want lisa to get ripped off by the garage, as we havent been there before.

cheers guys!

I've never taken a car to a car garage, but from my experience. Its pretty much luck.


Get a skilled Tech your well away, get a muppet with a spanner and your in for a rough ride.

Guys,

Thought I'd post an update...the garage replaced injector 4...offered a reconned one for £90, which I think is reasonable, based on the cost of new...The car now starts immediately...he also reset fault codes and changed MAF sensor (this bit was expensive, £220 for the part) then a few hours labour on top, but I have to say this mechanic is genuinely interesting in making this car run as it should. He has asked us to take the car back next week so he can retest drive wit the new injector fitted as he is still concerned the car is underpowered. But i would definately recommend this garage to anybody who doesnt have the technically know how, tools or the time.

How's it been running since?