It's bad to have a bad injector...

bmw_slayer · Post by **bmw_slayer** » 14 Oct 2005, 10:51

Hello all,

I am pleased to say I have recently come into the possession of a 97R ZX Turbo Diesel. It's in great condition, 70K miles, drives well, outperforms reppy in his 318i etc etc.

The only problem I've had with the car is cold starting. The car starts very easily from cold but runs rough on three cylinders for a few seconds before kicking in fully and emitting a moderate amount of white smoke.
This is only time the car has any kind of starting issue - if it's even slightly warm you are gauranteed a flawless start.

The glowplugs have been replaced. The guys down at Eurocars in Loughborough (highly recommended BTW) diagnosed a faulty injector. This makes sense as the engine seems far too new to have a compression problem. The car has had the usual fuel additive in the fuel filter / Italian tune-up treatment to no avail.

Bear in mind that the injectors will cost £35 a piece from GSF or £50 from a garage plus the cost / hassle of fitting and you can see why I am reluctant to have the whole lot replaced - I'd be looking at 1/4 of the value of the car. However, as I'm looking to keep the car for at least 2 years / 30K miles I would probably bite the bullet if this were my only option.

So, having said that...

1. Would it be viable to diagnose the faulty injector and replace only that? Haynes mentions unscrewing the injector then starting as a way of diagnosing faults. So, if I unscrew an injector and it starts the same as it does now I've got the right one. But if it's even worse / doens't start at all, I've got the wrong one... ...right?

2. Would an GSF-sourced injector work 'out of the box' of would it require any kind of setting up?

3. Is there any of source of refurbished injectors for these kind of engines in the UK, and if so, are they worth bothering with? Remember it's the cost of parts rather than labour that's putting me off getting the lot done.

Thanks for your help and I'm sure you'll be hearing more from me in the future!

Post by **Sir Clive** » 14 Oct 2005, 11:08

It depend whether your car is fitted with a Bosch or Rotodiesel fuel system. The Bosch injectors are usually done on an exchange basis, whereas the Rotodiesel ones are normally fitted with new nozzles. The best thing you can do is look in the Yellow Pages for a local diesel injection specialst and take it along to them to have a look at.
Hope this helps.

robsons · Post by **robsons** » 14 Oct 2005, 11:43

Before you spend money try this first. Pump the fuel primer until it gets hard then try it. If it's better then it's due to a small air leak in the pipes to/from the injectors - The little rubber ones I think. See if this makes a difference and then look up "air leak" "starting" and "smoke" on this forum and you'll probably have your answer. A clue is if the primer's not hard in the first place ('cos air's got in there)

fastandfurryous · Post by **fastandfurryous** » 14 Oct 2005, 11:44

last time I had recon injectors, they cost £15 each on an exchange basis.

A good diesel injection company will be able to pop your injectors on a test rig, and diagonose within seconds.

An alternative is to just grab a set of injectors from a scrappy for £5 each (make sure they're from the correct engine capacity and the correct make of pump) and change them. You can usually see a worn injector, as the area (slightly smaller than a 5p-piece) around the injector pintle (the nozzle) will begin to recess. Once it's recessed, the injection pattern goes all shonky, and you have your bad starting and slightly high fuel consumption.

jeremy · Post by **jeremy** » 14 Oct 2005, 11:59

I think Robsons is referring to the leakoff pipes which do perish and harden with age and can fail. With the Roto-diesel pump you will simply get a mess and small when they fail, but with the Bosch failure can allow air in the system. Having said that I don't think this is the source of your misfire if its always on the same cylinder.

I has the injectors cleaned on my BX TD some 5 years ago and the difference was amazing - in fact so amazing that the head gasket blew between 2 cylinders 18 miles later! (Car had done 175,000 miles and it was just a near coincidence.) Well worth doing and the car will go much better afterwards. Mine were done by a local specialist for the same money or less than I could have bought the injectors for.

bmw_slayer · Post by **bmw_slayer** » 14 Oct 2005, 13:41

Thanks for all your advice... I'll have a go at pumping the fuel primer first, just in case.

I've phoned my local diesel specialist. They will charge a flat rate of £50 to test the injector nozzles plus the cost of each nozzle that needs to be replaced (the car has a lucas pump).

Sounds like a more sensible solution all round, all I need to do now is get them out of the car...

jeremy · Post by **jeremy** » 14 Oct 2005, 14:15

How much more will they charge to remove and fit them for you? The reason I suggest this is that there are some special washers that are needed and they will either have them or if appropriate re-use the old.

fastandfurryous · Post by **fastandfurryous** » 14 Oct 2005, 14:18

£50? Blimey that's expensive.

The last place I went to would test them for free if they were off the car and just handed to them! it only takes about 30 seconds to test each one!

When I went there I drove the car to them, took them out on their forecourt, had them tested, bought 4 recon injectors, fitted, and drove home. Total cost of £60. They even gave me a set of copper washers and fire-seal washers for free.

Just go equipped with a 27mm deep socket!

Post by **Sir Clive** » 14 Oct 2005, 14:19

I've phoned my local diesel specialist. They will charge a flat rate of £50 to test the injector nozzles plus the cost of each nozzle that needs to be replaced (the car has a lucas pump).

Sounds like a more sensible solution all round, all I need to do now is get them out of the car...[/quote]

Be aware that you *must* use the correct socket to get the injectors out...it's possible to get an ordinary long one to...erm...fit, but you'll break the connections for the leak off pipes from the injector body, which is very bad news

Most decent motorist type shops should have the proper tool...I've even seen them in some branches of Halfrauds.

fastandfurryous · Post by **fastandfurryous** » 14 Oct 2005, 14:28

Interesting.

I've never used anything other than a six-side 27mm deep socket. Never broken a leak-off connector off, and never had a problem

Actually, I tell a lie.. I have also used a 27mm ring spanner, but it's a bit of a guess to torque them up correctly... not recommended!

bxbodger · Post by **bxbodger** » 14 Oct 2005, 14:59

Hello BMW slayer, Go to my old posting about injector renewal-http://www.frenchcarforum.co.uk/forum/v ... 1&start=15, and there you will find the part numbers for the washers you'll need if you take it out yourself.

Post by **Sir Clive** » 14 Oct 2005, 15:21

fastandfurryous wrote:Interesting.

Actually, I tell a lie.. I have also used a 27mm ring spanner, but it's a bit of a guess to torque them up correctly... not recommended!

Blimey, I can imagine its not the handiest tool to do the job with

fastandfurryous · Post by **fastandfurryous** » 14 Oct 2005, 22:10

depends... on an early square-port non-turbo engine there's plenty fo room to get a big (18" long) ring spanner in. Not quite the same on late TD engines!

bmw_slayer · Post by **bmw_slayer** » 17 Oct 2005, 15:41

robsons was not wrong...

Before starting yesterday and today I pumped the primer and on both occassions... ...hey presto, 4 cylenders from the word go. Now I really feel stupid for having those glow-plugs replaced!

Looks like some more detective work is in order.

pete_wood_uk · Post by **pete_wood_uk** » 20 Oct 2005, 13:10

bmw_slayer wrote:robsons was not wrong...

Before starting yesterday and today I pumped the primer and on both occassions... ...hey presto, 4 cylenders from the word go. Now I really feel stupid for having those glow-plugs replaced!

Looks like some more detective work is in order.

Try the daisy-chained leak-off pipes that return excess fuel from the injectors to the pump. I had a tiny air-leak in one of those and lousy starting for ages - took me quite a while to find it, 'cos I'm clueless - I had braided ones and they seemed to have just a small enough split that diesel wasn't getting out, but air was getting in overnight....

Cheers
Pete