T4 : Battle Across Time (2010 to present)

[Activ8]

Pulled out another manifold to prep today.
This one came from a healthy Crafter 2.5TDI , looks almost identical to the AXG / AHY swan necked type. I'll add a pic of both together. If you're looking to buy one - they can be expensive - , cheap units tend to gain cracks through the cast so be aware! The turbo flange is designed to take a Garrett T25 housing, one of the commonest flange types.


The obvious difference is the EGT sensor fixings precast in the design exactly where it needs to be just before the turbo inlet. Got an old gasket to template the porting work to be done. The die grinder makes short work of such tasks. First it needs cleaning up.....

[Activ8]

Back on the injectors today while the manifold soaks in some Bilt Hamber and a couple of the old nozzles get ultrasonically cleaned.

I'd already wiped over the injectors 1st with surgical spirit 2nd with Rockoil detergent 3rd with a clean rag soaked in calibration test fluid before testing at the weekend

DON'T use steel brushes for cleaning the nozzles! Thats what your Mrs' ultrasonic jewellery cleaner is for!!

The TDI uses a two stage two spring system to deliver an initial injection (for cooling the rising cylinder pressure as it reaches TDC) & the main injection.

At the weekend I'd checked the oem nozzles , injector bodies etc and made a note of the condition pressures and passes.

Three things you need to check;
1. OPENING PRESSURE
2. LEAKAGE
3. SPRAY PATTERN

1. On the pop testers you can buy its only possible to test the initial injection. Bosch Service agents may have the electronic versions (old skool now) with the extractor for collecting the oil mist from entering the atmosphere, but often aren't interested. On that note, its probably worth wearing suitable PPE when pop testing.

Bosch also state that the "tolerances are so close on nozzle replacement that opening pressure setting for stage 2 is not required."

The opening pressure is set by the PRESSURE PIN. (see pic, part #7)

Unsurprisingly theres a Bosch range of these pins....
Range 1 goes from pin lengths 28mm to 30mm
Range 2 goes from pin lengths 33mm to 35mm
Range 3 goes from pin lengths 43mm to 45mm
The pins with individual part numbers are supplied in 0.02mm increments.

YOU DON'T TOUCH OR REMOVE THE 2ND MAIN SPRING OR SHIM. BOSCH STATE THEY'RE SIMPLY REUSED.

Upgrade your nozzle and pop test.
The torque setting for the holder assembly is 40-50Nm.

You may need someone elses help or use video to capture the initial "pop" break pressure, spray pattern and signs of leakage.

To increase or reduce the pressure stage change the pressure pin length.
According to Bosch 0.02mm= 4-6bar.
So your break pressure was 200, so by increasing the pressure pin length to +0.10mm, you would add 20-30bar to the opening pressure.

A couple of mine were 34.10mm, 34.30mm & 34.34mm but were within tolerance, 220-230bar.

I can post a list of the part numbers and pin lengths if anyones actually interested?

So measure and keep a record of the pressure pin lengths, might save time next refurb perhaps.

TBC....

[Activ8]

Ordered both the injector pressure pins and shim spares today. The pins are available individually and the shims I found as a 100pc set (5 × the incremental sizes of which there are 20 in a bag). So happy days for £50.

The pins l ordered were a selection.of random sizes on or around the pin sizes in my two sets of Bosch. I want to try following the Bosch instructions and compare the two results, pin change and 1st shim change.

Ive read on another forum that straight swapping new nozzles roughly drops the opening pressures by 20-30 bar. I'll check that too.

[Activ8]

Blast media arrived quick - 25KG next day with dpd. Premium Glass Grit Fine/Medium 0.2-1.0MM x 25kg Bag, check out their website.

[Activ8]

Bosch injector seals arrived - quality.

[Activ8]

The Ultrasonic Cleaner arrived this afternoon and put to work / test shortly thereafter. Digital controlled heater( max 60°C) albeit the sonic action.causes a temp rise and count down timer 5-30 minutes.

Quick test in water with a plastic kitchen frother and alls well. So I placed a spare non T4 nozzle in for some ultrasonic treatment. An old microwave dish with Rockoils DLA and a single nozzle. 5 minute bursts with no heat in 200ml of water in the stainless unit. With no heat added the sonic transducer(?) raises the temp by about 5°C every 5 minutes according to the "Actual" temp gauge. The DLA was bubbling nicely attracting the attention.of the Mrs. The DLA perfume wasn't to her liking in the kitchen. Lol.

The sonic action.dislodged, released and cleaned the nozzle pin after 3 x 5 minute sessions with no effort from me. Its been stuck like that for 7+ years at least and nothing has ever shifted it. RESULT.! Ran it for a 4th & 5th session with the parts seperated. The parts get hot but nothing that you cannot handle. The sonic action also dislodge the two tiny locating dowels that seat the nozzle in the adaptors.

Chuffed with that.
So I'll order a big bugger for much larger components.

[regcheeseman]

Does the ultrasonic also repair fucked nozzles?

[Activ8]

Does the ultrasonic also repair fucked nozzles?

What.... because the dowels have come out of my test nozzle?

[regcheeseman]

As you took the time to PM me, let me elaborate or my previous regesque response.....

That nozzle is obviously fubarred, I didn't see the point of cleaning it but understand now that it was a test of the US, and as such they are not clean.

What.... because the dowels have come out of my test nozzle?

No, because how dirty do you believe nozzles get when they are jetted through with diesel (a good cleaner) at 200+ Bar.

Ultrasonically cleaning diesel injectors is largely a waste of time, if you have dirt in the fuel system then you have bigger issues, baked on deposits are just as effectively removed by an Italian tune up or running some veg/petrol/snake oil through. Just like spark plugs they will soot up and self clean depending on how the engine is run/setup.

You told me that my stanas would clean up after a remap - they didn't because they were fucked, well they might have cleaned up but the running didn't improve because they were fucked.

Yes you may see some improvements for a while from cleaned injectors; worth the hassle or pulling stripping cleaning rebuilding refitting ??? dunno? If I was going through that hassle I'd bung new nozzles in if there was any doubt.

[Activ8]

As you took the time to PM me, let me elaborate or my previous regesque response.....

That nozzle is obviously fubarred, I didn't see the point of cleaning it but understand now that it was a test of the US, and as such they are not clean.




No, because how dirty do you believe nozzles get when they are jetted through with diesel (a good cleaner) at 200+ Bar.

Ultrasonically cleaning diesel injectors is largely a waste of time, if you have dirt in the fuel system then you have bigger issues, baked on deposits are just as effectively removed by an Italian tune up or running some veg/petrol/snake oil through. Just like spark plugs they will soot up and self clean depending on how the engine is run/setup.

You told me that my stanas would clean up after a remap - they didn't because they were fucked, well they might have cleaned up but the running didn't improve because they were fucked.

Yes you may see some improvements for a while from cleaned injectors; worth the hassle or pulling stripping cleaning rebuilding refitting ??? dunno? If I was going through that hassle I'd bung new nozzles in if there was any doubt.

What does regesque mean?
Is that Latin?

Anyways it was a simple test of the ultrasonic cleaner. An old nozzle proved the usefulness of the USC breaking down the carbon deposits on a particularly unloved old nozzle.

Quite true, Bosch recommend replacing the nozzle, nozzle holder and adaptor when servicing. Theres no narrative to their recommendation.

I doubt if any - except you perhaps - actually would fit new though unless upgrading, the outlay of say £300 would be too much? A US clean and reset might be the half way house for those without the kit, bucks and motivation.

Your Stanas (whatsapp video) were opening at 150 bar iirc. So 70-80 bar too low. Shimmed, cleaned and retested might of given you another 150k miles from them. You wrote them off as you had an alternative to fit.

[regcheeseman]

regesque might need a hypen reg-esque as in 'reg like'

Your Stanas (whatsapp video) were opening at 150 bar iirc. So 70-80 bar too low. Shimmed, cleaned and retested might of given you another 150k miles from them. You wrote them off as you had an alternative to fit.

Its like banging your head against a brick wall sometimes isn't it. I got the alternative to fit because I new they had had it before I even took them out, if I'm spending out on new nozzles, why wouldn't I go for an upgrade and possibly the best reviewed brand you can buy?

They were fucked, ruined, wrecked, worn out, shagged, trashed, knackered ......just accept it.

I know what they were spraying like and I know how my van was running, cleaned and shimmed would have changed nothing


Oh and the gauge was under-reading on my pop tester, think I might have also mentioned this a few times? But yes they were breaking early, probably because they were screwed, broken, bin fodder, scrap.

[S49]

So to be clear Reg your saying your injectors were worn out?

[Activ8]

So to be clear Reg your saying your injectors were worn out?

I didn't get that impression Si..... I read that Reg hadn't tried thats all. ;-)

Its odd though isn't it, theres nothing I've found in manufacturers service schedules about resetting injectors despite their clear affect on the pollution and emissions they create despite the weight of the legal requirement placed on manufacturers since 1996.

[regcheeseman]

So to be clear Reg your saying your injectors were worn out?

Maybe, Its possible that I could have cleaned them up


with a hammer

[Activ8]

Maybe, Its possible that I could have cleaned them up ...

See told you!