Leaky Injectors?

[Jersey Royal]

Hi All

 

Quick question

 

Should the injectors leak fuel out when the ignition is on (ie pump in boot running only no spark)?

 

As all six of mine do, they do not rattle, fuel pressure is 100 through prestige new pressure relief valve.

 

Cheers

 

Guy

 

Well found out that the above isnt normal, and the injectors are most probably ok, and this could be due to internal seepage on the MU itself.

Edited July 30, 2008 by Jersey Royal

[Richard Crawley]

Continuous injection is caused by damaged grommet seals on the M/U distributor outlets or damaged inner O rings on the banjo type connectors. They must always be replaced if you disturb them. I'd also up the line pressure a bit!

Edited July 30, 2008 by Richard Crawley

[Jersey Royal]

Continuous injection is caused by damaged grommet seals on the M/U distributor outlets or damaged inner O rings on the banjo type connectors. They must always be replaced if you disturb them. I'd also up the line pressure a bit!

 

Thanks Richard,

What i cant work out is why a seal on the outlets would cause all six injectors to leak.

 

Not having replaced these before, do you think this is a simply job, i have taken of the mu in the past when i was replacing seals in the pedistal

 

 

Cheers

 

Guy

Edited July 30, 2008 by Jersey Royal

[Richard Crawley]

Guy

Yes they are fairly simple to replace but you will need to remove the unit from the engine. I would strip it out & check/replace the sleeve O ring as well; in fact if the control unit normally returns good MPG & does not require recalibrating, I would replace all the distributor seals & the diaphragm while your at it. Goes without saying absolute cleanliness is essential when opening up the fuel distributor. Don’t disturb the settings on the control unit springs or datum track!

 

I assume you’ve already downloaded free copies of the Lucas Training & servicing manuals? http://www.lucasinjection.com/

[Jersey Royal]

Guy

Yes they are fairly simple to replace but you will need to remove the unit from the engine. I would strip it out & check/replace the sleeve O ring as well; in fact if the control unit normally returns good MPG & does not require recalibrating, I would replace all the distributor seals & the diaphragm while your at it. Goes without saying absolute cleanliness is essential when opening up the fuel distributor. Don’t disturb the settings on the control unit springs or datum track!

 

I assume you’ve already downloaded free copies of the Lucas Training & servicing manuals? http://www.lucasinjection.com/

 

Richard

 

Thank you very much, Again

 

I have already got the Mu out of the motor and await the new seals to the outlets with a lot of luck they might get here saturday.

 

On a recent trip to Le Mans the car returned 26mpg, i have recently replaced pedestal seals, so am just going to replace the outlet seals, ( brown book page 19.35.14 sheet 2, as shown 10a ) but still cant fathom why those seals are causing the problems? Which is the sleeve o ring?

 

 

Cheers

 

Guy

Edited July 30, 2008 by Jersey Royal

[Jersey Royal]

Hi All

 

Update,

 

I have taken apart the metering distributor, and all the seals look fine.

 

One obsevation i had was that there was a layer of thin black rubber in both banjo bolt leads, where the lead goes around the bolt.

 

The unit had work on it a few years back by a diesell injector mechanic overhere, so whether thats a left over or someting new i dont know.

 

Is it possible that this could cause all six injectors to leak out.?

 

However i have updated my order to replace all seals including bung seals and new banjo bolts.

 

Another query, relates to the bung seals, according to the book they should be fitted with a special tool, havent got that tool, so do i just oil it and slide it in place, final position being achieved when the union connector is screwed in place, then check the sleeve assembly rotates smoothly???

 

 

 

Fingers crossed

 

Guy

Edited July 31, 2008 by Jersey Royal

[Jersey Royal]

Hi All,

 

Parts not arrived yet.

 

However, i have metal braided hoses on my injectors, can anyone confirm what the tube inside is made of ie rubber or pvc.

 

Cheers

 

Guy

[Bob Stubbs]

Hi Guy

 

Not sure if this is related to your problem but I put braided hoses on mine for about 6 months and after really rubbish hot starting and some advice from Mike Pumford, who builds M/U's I went back to the originals and have had no problem. As I recall, the tube diameter in the braided hose is bigger than original so there's an issue over the ability for fuel to stay in the pipe (surface tension or something......I know not). My main problem was the braid transferred to much heat into the pipe vapourising the fuel and causing it to be a dog to start from hot. Just my experience anyway but I know others seem happy with braid.

 

Cheers

 

Bob

[Jersey Royal]

Hi Guy

 

Not sure if this is related to your problem but I put braided hoses on mine for about 6 months and after really rubbish hot starting and some advice from Mike Pumford, who builds M/U's I went back to the originals and have had no problem. As I recall, the tube diameter in the braided hose is bigger than original so there's an issue over the ability for fuel to stay in the pipe (surface tension or something......I know not). My main problem was the braid transferred to much heat into the pipe vapourising the fuel and causing it to be a dog to start from hot. Just my experience anyway but I know others seem happy with braid.

 

Cheers

 

Bob

Hi Bob,

 

Not really had an issue with braided hoses and hot starting.

 

The hoses are now twelve years old, and when i strpped of the hoses, i found a strip of rubber in both banjo connections, not actually in the banjo but on the outside ring that connects to the hose itself., so being rubber and because it could not have come through the banjo non return valve (?) it could only have come from the pipe itself. So the pipe must have a rubber inside.

 

Is this logic correct? If so i think i will revert to the non braided variety.

 

Cheers

 

Guy

 

update... have taken a fitting of the end and can look down tube and it appears to be pvc or plastic , not rubber. So my logic is b**ls, rubber must have come from seals

Edited August 4, 2008 by Jersey Royal

[Peter Douglas Winn]

For what it is worth banjo seals are not squashable. So you can only tighten them up to a certain extent. If you tighten them up any more you will cut off slivers of rubber that will stick in your injectors. When assembling the banjos just tighten them lightly put the unit on the car. Then run it. If the banjos leak then just tighten them up sufficiently to stop the leak. NO MORE THAN THAT. Injectors do not leak if they are correct!!!!

[Jersey Royal]

For what it is worth banjo seals are not squashable. So you can only tighten them up to a certain extent. If you tighten them up any more you will cut off slivers of rubber that will stick in your injectors. When assembling the banjos just tighten them lightly put the unit on the car. Then run it. If the banjos leak then just tighten them up sufficiently to stop the leak. NO MORE THAN THAT. Injectors do not leak if they are correct!!!!

 

Thanks Peter

That would explain the rubber strip in the banjos, they were fitted by a diesel injector specialist overhere.

 

Guess i wont be using him again.

 

Parts still not here But thing my problem will come in fitting the six bung seals, thse go into thr rotor sleeve, apparently should be done with special tools.

 

Anyone had experience of fitting these pesky little things?

 

Cheers

 

Guy

[Jersey Royal]

Update.

 

 

 

Ordered seals 30 July, now the 08/08/08, just had a call from the Injection Specialist, asking me about a cable i had ordered!!.

 

Well didnt order a cable, and only now are the seals that were ordered some twelve days ago going to be in the post.

 

How is it that they stay in business, because with service like that i doubt that i will be using them again.

 

Am really not happy, means another weekend with car off the road.

 

Cheers

 

Guy

[stuart]

Guy you could always have a play with your seven if your looking for something to do!

Stuart.

[Guest ntc]

Update.

 

 

 

Ordered seals 30 July, now the 08/08/08, just had a call from the Injection Specialist, asking me about a cable i had ordered!!.

 

Well didnt order a cable, and only now are the seals that were ordered some twelve days ago going to be in the post.

 

How is it that they stay in business, because with service like that i doubt that i will be using them again.

 

Am really not happy, means another weekend with car off the road.

 

Cheers

 

Guy

 

Who was it Guy ? is that allowed ?

 

Regards

Neil

[Jersey Royal]

Who was it Guy ? is that allowed ?

 

Regards

Neil

 

 

 

Maybe they were having a busy time, bad hair couple of weeks and my small order was not that important, ,

 

Who knows but i dont hold them in high esteem at the moment

 

 

Cheers

 

Guy

[Jersey Royal]

Hi All,

 

Update.

 

I have replaced banjo bolts and seals, all outlet seals, pedistal seal and both rotor seals, as well as all bung seals. Metering unit is timed correctly.

 

I oiled the bung seals and located by pushing them slowly down till they were located in the rotor.

 

Bleed all injectors took for a drive, had to rebleed one.

 

Any way my problem remains

 

Having taken out just two injectors as engine was hot, with ignition on (no spark) the injectors leak

 

Help what have i done wrong.

 

I can feel a new car beckoning me

 

 

Any pointers gratefully recieved

 

Guy

[88V8]

Any pointers gratefully recieved

 

 

Call Malcolm Jones at Prestige Injection.

01978 263449

 

He will have helpful words for you.

Allow one hour.

 

Ivor

[Jersey Royal]

Call Malcolm Jones at Prestige Injection.

01978 263449

 

He will have helpful words for you.

Allow one hour.

 

Ivor

Hi Ivor,

 

Done that, one of the reasons i replaced all the seals

 

Cheers

 

Guy

 

After further investigation, checking all six injectors, it seems that its only now affecting 3 and four, so its maybe not as bad as i first thought, think i will take off 3 and four and ceck bung seals are fully home.

Edited August 11, 2008 by Jersey Royal

[Mike Collins]

You may already have done this, but if you take out the offending injector and gently blow into the inlet, can you detect slight leakage?

 

I had one of mine showing leakage, fortunately it was the circlip type, removed the internals, fitted another O ring and now ok.

[Jersey Royal]

Hi ALL,

 

I will not be defeated by this.

 

Having done the seals i still seem to have a problem with three and four. I have not taken them apart yet.

 

I often wonder if the stuff i stick in the tank as a lead fix for my engine has anything to do with it, or indeed the chemicals in todays fuel.

 

My thoughts are that the injectors when working are being kept cool to a certain extent by the fuel flowing through them, however when the car has been for a run and is hot then switched off, the injectors no longer get the cool fuel but the heat from the manifold /engine, causing the fuel in the tip to heat and evaporate leaving behind certain residues on the tip, over a period of time this could build up.

 

So what do you think of my thoughts? and would an injector cleaner help, if so any particular one.

 

Cheers

 

Guy

[88V8]

I will not be defeated by this.

 

.... when the car has been for a run and is hot then switched off, the injectors no longer get the cool fuel but the heat from the manifold /engine, causing the fuel in the tip to heat and evaporate leaving behind certain residues on the tip, over a period of time this could build up.

So what do you think of my thoughts? and would an injector cleaner help, if so any particular one.

 

Good for you.

 

Your hypothesis is interesting. However, if this were the case I suspect it would be pandemic.

Unless your local fuel is especially dodgy? Is there perhaps a low turnover?

 

I'm sure you would do no harm with a traditional cleaner like Redex, although I doubt it would do much good.

Really, you know, for the trivial cost, why not just send the offending injectors to Malcolm, ask him to report on them, then fit two of his recons....

I entirely endorse your desire to be self-propelled, I hate paying others to do what I should try and do myself, but no point in flogging yourself to death trying to be expert in everything...

 

Ivor

[Jersey Royal]

Good for you.

 

Your hypothesis is interesting. However, if this were the case I suspect it would be pandemic.

Unless your local fuel is especially dodgy? Is there perhaps a low turnover?

 

I'm sure you would do no harm with a traditional cleaner like Redex, although I doubt it would do much good.

Really, you know, for the trivial cost, why not just send the offending injectors to Malcolm, ask him to report on them, then fit two of his recons....

I entirely endorse your desire to be self-propelled, I hate paying others to do what I should try and do myself, but no point in flogging yourself to death trying to be expert in everything...

 

Ivor

 

Hi Ivor,

 

Just pulled them again and well they all still leak to a leser or greater extent.

So, maybe i should get hold of some recon injectors fit them and see.

 

Cheers

 

Guy

[Richard Crawley]

Are you still getting continuous injection or is the problem now just to do with fouling/dribbling of the injectors themselves? If you’ve used Viton seals, modern fuel or any additives your using shouldn’t be a problem with the rubber itself & even if they are not Viton it would take longer to affect the rubber than in your case. I don’t use additives so have no idea if these can/will leave a residue build up but I suppose it’s entirely possible; but then it would affect all the injectors, not just 3 & 4! I assume it’s not the injector poppet valve seats themselves letting by & you’ve tried swapping the injectors around. Only other thing I can think of is that you’ve somehow missed/done/not done something when rebuilding the metering distributor. It can sometimes be infuriating & I initially had my latest recon unit off & on at least half a dozen times because it kept popping the diaphragm off it’s seat. Totally frustrated, in the end I sent it back to Prestige where Malcolm diagnosed an internal blockage causing a build up of pressure around the rotor which kept popping the diaphragm; he cured it but I had to pay to have a whole new set of seals fitted.

[Jersey Royal]

Are you still getting continuous injection or is the problem now just to do with fouling/dribbling of the injectors themselves? If you’ve used Viton seals, modern fuel or any additives your using shouldn’t be a problem with the rubber itself & even if they are not Viton it would take longer to affect the rubber than in your case. I don’t use additives so have no idea if these can/will leave a residue build up but I suppose it’s entirely possible; but then it would affect all the injectors, not just 3 & 4! I assume it’s not the injector poppet valve seats themselves letting by & you’ve tried swapping the injectors around. Only other thing I can think of is that you’ve somehow missed/done/not done something when rebuilding the metering distributor. It can sometimes be infuriating & I initially had my latest recon unit off & on at least half a dozen times because it kept popping the diaphragm off it’s seat. Totally frustrated, in the end I sent it back to Prestige where Malcolm diagnosed an internal blockage causing a build up of pressure around the rotor which kept popping the diaphragm; he cured it but I had to pay to have a whole new set of seals fitted.

 

Hi Richard,

 

Hope you had a good holiday, nice to get away once in a while, epecially somewhere warm.

 

I had thought it only now affected 3 and 4 but unfortunately there is no change really, affects all to varying degrees. Have looked at the injectors closely and the fuel does come from the very tip of each injector as if the springs are weak or fuel pressure to high.

Fuel pressure is fine

 

So my options are...

 

Get six recon injectors, which would illiminate them

 

Recheck seals to Mu, but that would mean a new set of seals.

 

Send of Mu to Prestige to sort out

 

Cheers

 

GUY

[Richard Crawley]

Hi Richard,

 

Hope you had a good holiday, nice to get away once in a while, epecially somewhere warm.

 

I had thought it only now affected 3 and 4 but unfortunately there is no change really, affects all to varying degrees. Have looked at the injectors closely and the fuel does come from the very tip of each injector as if the springs are weak or fuel pressure to high.

Fuel pressure is fine

 

So my options are...

 

Get six recon injectors, which would illiminate them

 

Recheck seals to Mu, but that would mean a new set of seals.

 

Send of Mu to Prestige to sort out

 

Cheers

 

GUY

Hi Guy

I’m actually still here in sunny Spain & will be until Sept 4th & by the look of the weather back in the UK, I’m in the right place; is it any better in the Channel Islands? It’s more a “live away” rather than a holiday as we just swap homes with the wife’s sister which means I have chores to do like gardening, running repairs etc; it can be rather hazardous tending & pulling weeds in a cactus garden, you have to very careful how you move around! It’s also a bit bloody hot for gardening; only 30 ish today but it‘s been as high as 37. We do get out to see some of the sights & for the odd meal with a couple of the neighbour ex-pats but my personal finances wouldn’t stretch to sightseeing/dinning out every day for 5 weeks!

 

Continuous injection would almost certainly point to a metering distributor fault usually the non return valves or the internal O ring on the rotor. Too low a blow off pressure or faulty poppet valve on the injectors won’t help matters though & from what you’ve said it sounds as if they may be well past their best. You can strip these, lap in the valves & re-set the blow off pressure fairly easily using an air line & pressure gauge; years ago I even used a modified car foot pump with a pressure gauge fitted which worked fine. There is nothing you can’t really fix yourself with the injectors, it’s just the hassle of stripping them, lapping the valves & setting them up but if they look a bit tired, it may be easier for you to get six nice shiny new ones; but if you’ve got the little nylon strainer cups fitted in the end, remove them before you exchange so you can fit to the new ones; they are like hens teeth & the recon units won’t have them fitted.

 

It might be worth stripping & checking the distributor again even without a new set of seals; yes I know what it says about always replacing them but I‘ve done it before without problems on fairly new seals. If that doesn’t cure it & the M/U is of any age, I would be tempted to go for an exchange unit as chances are the control unit will be out off kilter anyway, usually running too rich; they only last around 20k before they start to drift & need recalibrating. I would use Malcolm but be careful & check beforehand that the exchange unit comes with recon. one way valves, some don’t & if you send yours back without removing them it‘s a big oh dear!