help me prove this to a customer ! injector problem

[Dr HMS Derv Destroyer]

hi all, recently had a dci come in , 2004 delphi 1st gen k9k.

the customer dropped the car off to us with a problem ,
the problem consists of first start after car being sat still over night.

glow plugs have been tested and fine. inc glow plug relay/timer
glow plug light goes out, go to start it and it will start but only revs itself too 700rpm and then dies.
fire up again and its fine and will idle perfect, and drives perfect.

no faults found, fuel filter split and inspected for contamination of a failed pump, to which no metal parts found. in tank strainer checked and not clogged.
brand new fuel lines fitted at renault dealership last month.

new filter fitted, OBD diagnostics on live data shows 290bar on cranking, as soon as the engine starts the pressure drops completely off.

second fire up shows 290/300bar and then holds nicely on idle.

leak off test has been done and found N0'2 injector ( french side gearbox end )
to leak back excessively , all the others return a minimum amount.

am i right in thinking this injector is sticking open, caulsing a big pressure drop, which inturn needs two starts to get it to go?
runs fine all day after that, until the next morning.

can anyone back up my diagnosis ?
the guy is a very picky customer ( and should be after having his pants removed by renault ) , i would just like to put down some hard evidence and back up from other people. a full printed report will be handed to him before ordering parts.
@MicKPM @Dan@SJM

thanks
raz

 

[Ross-gt128]

Had the same problem with mine! Turned out it was injector seals rather than the actual injector itself! Although mine didn't run perfectly all day after it first start, sort of came and gone. Mite be my tired brain thinking but I'd imagine there would be to much pressure in the fuel lines itself to feed pressure back into the lines if the injector was stuck open, like I said I'm not sure, just a thought!

 

[clioben182]

Can someone who has access to dialogys find the procedure for carrying out injector leak off test for you?
This should explain everything.

Ive had a look on mine but cannot seem to find it.

Your findings are correct the injector is not using the fuel its being delivered and is returning it for whatever reason. This needs sorting first then keep testing it in the mornings.
Hope this helps

 

[MicKPM]

You've seen on screen fuel pressure drop.

You've also done a leak off test which shows conclusively that Inj 2 is returning more fuel that it should

What more proof are you looking for? Injector is ballsed and needs replacing/refurbishing... the end

 

[karol_SVK]

Try disconnecting the injector. Running on 3 cylinders is not nice but if it does not cut out than it supports your theory. Had an idea of fuel pressure regulator, Did you test another one?

Just my ideas

 

[Dr HMS Derv Destroyer]

Thankyou.

Just needed to double check my finding are conclusive.
Last thing I need is the bloke bleating at me after Renault themselfs throwing a set of fuel lines on ( unless they found a damaged quick connector )

Will file a report later for when he comes up.

 

[Dr HMS Derv Destroyer]

IMV on the pump got changed by Renault. Old one has a damaged plug connector.
rail sensor is fine, it's not shooting all over the place or showing 2000bar like they do when fubard.

As for disconnecting injectors , I can make mine run on three with one disconnected so I don't see how disconnecting the bad one on this one will have a difference . Rather not faff about and creat more problems

Ive already stated the price of an injector to him.
£105 for a new one or his one exchanged for a recon at £85.
( both from car woods diesel supply's )

 

[Dan@SJM]

I'm with mick and you Raz. Fucked injector.

 

[MicKPM]

Tell him to either take the advice or take the f**king car but either way, stop wasting your time.

 

[Dr HMS Derv Destroyer]

I know mick!

 

[Diagro]

The customer needs to understand it's not an easy thing diagnosing a car.

its the norm to have various parts replaced to fix a problem. You have to start somewhere.

I as a customer have spent hundreds on parts that were fine. But in my eyes I at least know those parts are now refreshed and I won't have them fail on me any time soon

 

[Owen92]

The customer needs to understand it's not an easy thing diagnosing a car.

its the norm to have various parts replaced to fix a problem. You have to start somewhere.

I as a customer have spent hundreds on parts that were fine. But in my eyes I at least know those parts are now refreshed and I won't have them fail on me any time soon

Not true. A good technician should be able to diagnose the majority of faults and rectify them by only replacing the causual part. Yes sometimes there are times where that isn't possible, but those times should be the minority.

 

[Diagro]

Not true. A good technician should be able to diagnose the majority of faults and rectify them by only replacing the causual part. Yes sometimes there are times where that isn't possible, but those times should be the minority.

If only that was true though.

Renault dealers are useless. My local garages are useless.

One of them actually told me the following:

"Its good that you have a good job, Its so hard nowadays to fix everything right away..
We stopped giving quotes because customers wouldn't pay when we had to fit various parts to fix an issue and it was more expensive."

This garage is booked everyweek and has a decent rep around here.

 

[Owen92]

If only that was true though.

Renault dealers are useless. My local garages are useless.

One of them actually told me the following:

"Its good that you have a good job, Its so hard nowadays to fix everything right away..
We stopped giving quotes because customers wouldn't pay when we had to fit various parts to fix an issue and it was more expensive."

This garage is booked everyweek and has a decent rep around here.

As a technician myself, I know that it can be hard to diagnose a fault, but it's very rare that anything I work on requires parts chucking at it in the hope that it cures the fault.

 

[MicKPM]

I've got a 1.4 16v Meg II come in today with zero throttle response, just splutter splutter cough cough. Ignition and injection functioning fine on the Scope, compression is balanced and everything looks fine in CLIP but it just will not rev freely. A previous garage has thrown coils, plugs, injectors and H02 at it so i dread to think how much its all cost to date. Gonna check timing on Monday morning otherwise it's being set on fire!

 

[Dr HMS Derv Destroyer]

rule of elimination. take all possibilities out of the equation and yo are left with a few routes.


the bloke is happy with me to change the injector. will have to wait til Monday to order one in.
he's also told me the timing belt hasn't ever been done since he had it from new ( its now on 89k )
so i have now the delighted task of that aswell.

i bloody hope its all fixed after !

 

[Mike@Rentech]

I've got a 1.4 16v Meg II come in today with zero throttle response, just splutter splutter cough cough. Ignition and injection functioning fine on the Scope, compression is balanced and everything looks fine in CLIP but it just will not rev freely. A previous garage has thrown coils, plugs, injectors and H02 at it so i dread to think how much its all cost to date. Gonna check timing on Monday morning otherwise it's being set on fire!

Fuel pressure, had one 2 weeks ago fuel pump filter was clogged with black plastic flakes from what I suspect was from a faulty filling station pump, exact same symptom.

 

[MicKPM]

Thanks for the heads up Mike I will deffo give that a look. I was going to do an in line pressure test at the rail to on Monday but I think I'll check the tank to.

 

[Dr HMS Derv Destroyer]

Fixed! New injector all sorted. Ran some liquid moly through yesterday.
First turn of the key this morning and no problems.

 

[Seoi-nage]

Was just going to say that the injector 100% needs replacing. It was leaking off excessively, you can't argue with facts, its faulty. Not all faults are caused by 1 issue, they are the ones that are the exception