Engine Misfire deisel

[rjb1957000]

Dd you need all 4 glow plugs to work ,or this will cause bad starting,and running.For example rough tick over? would it be a combination of blocked injetors,and faulty glowplug/s

[NORMANTHEDOG]

having things like glow plugs and spark plugs and injectors working properly is paramount to a engine of any type running smoothly,it sounds like yours needs a bloody good service

[rjb1957000]

Thanks,had to drain water from the injector holes,but think the injectors are blocked because of the blue /grey smoke. shall give this a try...thanks again

[wudz]

Hi just to help you, the glow plugs are to help start the car..warm up the fuel/air at starting thereafter the are out of equation on smooth running. Once the car is running the injectors are the prime cause of missfire if the fuel filters are clean and no air leeks in the supply line along with a working fuel pump.

Cheers
John

[rjb1957000]

I thought that was right ,shall check the injectors....thanks for for your reply

[mr rusty]

For a diagnosis you really need to be more precise on exactly what's happening and when. As a general gude, however, an old style diesel will chuck out three types of smoke, which all mean something different.

White smoke on start-up is normal, it's unburnt fuel that's pumped out of the combustion chambers before the engine fires: once it starts to run on all cylinders it stops smoking. Faulty glowplugs will cause this to go on for some time, however, as the engine catches, stalls, catches, over and over as it struggles to start without preheating.

Black smoke as you accelerate is caused by overfuelling: basically too much diesel is being burned, more than you need, and the usual cause of this is either a blocked air filter or leaking and dripping injectors which are too worn to close properly, it's also sometimes caused by misguided attempts at increasing performance by turning the fuelling up: it doesn't work unless more air is pushed in as well, which is what turbos are for....

Blue smoke is burnt engine oil, caused by a worn engine.

If you only have a problem at start up and for the first few minutes, this would point to faulty glowplugs or a faulty relay, or possibly air getting into the system: does it help if you prime the pump before starting?

Leave the injectors well alone. You only need to do anything with them if there is BLACK smoke under acceleration or, in bad cases, normal running. Don't be tempted to get them out and fiddle with them, they are precision instruments, there is nothing you can do with them on a DIY basis. If they are shot, you need to get them reconned professionally, �100 to �150 for all four- good value really as you only need to do it every 150000 to 200000 miles.

If you are talking about a common rail system however, you have the electronics to contend with as well which is a different ball game again!

[rjb1957000]

Thankyou for your very detailed reply ,initially the engine had to be drained of flood water ,by removing the injectors. It started o.k but Is running very lumpy. One friend commented the smoke was" possible unburnt fuel,"the smoke Is white/grey coloured If that helps in identifing the problem.

[feellinold]

I have had a similar problem with a Citroen BX some time ago. The problem was caused by air leaking into the supply line between the pump and injectors.

[rjb1957000]

Thanks ,have checked all the parts that I can think of shall either get someone to have look,or drive steady to the nearest garage,1/2 mile away.....thanks for replying!!