200tdi missing on idle

Hi everyone this is my first post so please bear with me as I am not great at this sort of thing lol
I have a 90 with a disco 200tdi in it and I cant seem to get to the bottom of this missfire it starts spot on goes very well but when I let it tickover it runs really rough I have checked the fuel pump timing changed the lift pump but it still does it there is no smoke except a puff off black smoke on start up and if you labour it. I have cracked the injectors off and the 2 closest the bulkhead make a big difference and there seems to be alot more pressure behind them than the other 2 and also there doesn't seem to be any fuel comming out of the injector spill rail when I pulled the braided rubber hose off. Any help or advise would be most appreciated as I am fed up banging my head against the wall

I had similair fault with my disco tdi engine in a series 2, was convinced it was the injectors, doing the same as you cracking and the pipes and replacing the one weak one, would be fine for a week or two then would do the same again, once 130 miles from home on 3 cylinders, fuel filter off, filled it with injector cleaner and after 10 miles it cleared and was fine for the rest of the trip, then next day it started again!
I even took the injectors to work and tested them, all fine.
Got a second hand inj pump and its been fine ever since
I suppose its not just idling to slow?

Hi no its definitely not running to slow as I have played with the idle speed as if I make if idle to fasf its fine and soon as I drive or rev it goes the strange thing is sometimes its worse than others

i had similar recently, i took the injectors to be tested, the flow pattern was none existent, and some leaked under pressure,
I had them re built at less than £200 it feels like a sports car now, and idles spot on, it only costs around £5 per injector to be tested, I would say its money well spent

Yeah I had thought of getting the injectors refubish but wasn't sure if it was them as the 2 injectors nearest the front of the landy don't seem to have as much pressure behind them when I crack off the nut but the 2 nearest the bulkhead have alot more pressure and there doesn't seem to be anything coming off the spill rail so I am thinking could the injection pump be at fault?

If the injector is leaking / dribbling it will not have as much pressure.

Most injector shops dont charge anything to test the injectors
Buy some sealing washers and swap them around, then crack them, if the problem has moved its the injectors if its still on the same cylinders could be pump problem.
Have you checked for air leaks before the lift pump?
Its only a piece of nylon pipe and costs pennies to replace, dont buy land rover stuff, you just need nylon truck air brake pipe.
Also worth removing the fuel tank pick up and checking that for damaged ie any way that air can get in.
You can use rubber fuel pipe, its okay but doesnt last forever, certainly easier to fit and route etc

Thanks for your reply if the injector is leaking/dribbling would the engine smoke?
anyway I think I will get my injectors checked tk rule it out does anybody know of anywhere near Guildford?

Phil90 said:

Thanks for your reply if the injector is leaking/dribbling would the engine smoke?
anyway I think I will get my injectors checked tk rule it out does anybody know of anywhere near Guildford?

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had mine done here, not near Guildford but they offer a postal service
http://www.dieselbob.co.uk

No I haven't checked for leaks but I will pull the tank apart tomorrow and swap some injectors around as I have some spare sealing washers. I did take her for a drive today and it doesn't seem as worse when she gets hot so I dont know if that means anything?
I really appreciate everyone's help thank you

Just thought I would post a update I think the problem is the injectors so I have sent them off to diesel bob today
but I also found the fuel pipe from the lift pump to filter was leaking a little so I have fixed that so fingers crossed new injectors should cure it

Any leaks after the lift pump arent really an issue apart from mess, its the ones before that let air in and cause all sorts of confusion.
Before the lift pump the pies are vacuum after lift pump they are under pressure.

I thought the 200tdi injection pump was capable of sucking diesel once engine running ,so if demand is high there is the potential to pull air into injection pump.
Hence not been necesary to manually bleed on 200tdi discovery.

Will check the rest of the fuel line for leaks and have a good look over the fuel pickup so I can rule it out just waiting for the rain to stop thanks again for all the help

Blackburn said:

I thought the 200tdi injection pump was capable of sucking diesel once engine running ,so if demand is high there is the potential to pull air into injection pump.
Hence not been necesary to manually bleed on 200tdi discovery.

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That is correct, but it will be down on power with a duff lift pump, in fact I can tell when my lift pump is on its way out and when new one fitted theres a nice little gain in power

Lynall thats intereseting as I was suffereing a lack of power on hills last weekend will need to check my lift pump out.

All the replacement pumps are ****, lucky to get a year out of one.
I think Ive had 3 poss 4 in the last 3 ish years, 1x britpart, 2x allamakes
I have bought but need to get around to fitting an electric fuel pump, facet from ebay, mate bought one for his camper can, I was very impressed with the quality and how quiet it ran.
The thing is if you drive it every day you dont really notice its lacking until you fit a new one and can certainly tell its a little nippier.

Hi all I have fitted new injectors as the spray pattern was rubbish and all the pressure was wrong but the missfire is still there if anything it is worse! I have checked fuel lines for leaks it has had a new lift pump a month ago
I have now turned the idle up to cure the miss so she is running a little fast but as soon as you make the engine work by turning the steering or pulling away with out using the accelerator the idle drops back to the missfire until you blip the throttle also I have noticed a sort of ting ting sound every now and then
appart from setting fire to it I am stumped:frusty:

Looks like inj pump then, not hard to do just time consuming if you havent got the tool to hole the cam pulley in place.

Yeah I think you're right but its the one thing I really didn't want to replace as if I get second hand you never no if its any good and I hate to think what a new one will cost?