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  #11  
Old 04-23-2020, 04:05 AM
blix99 blix99 is offline
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Hi. Thanks again for the reply.

So, I did decide to buy new injectors but they are set up for DV engine (D2.4t so I understand)

I have fitted them as I needed to get the engine going again (and van moved) and it's much better now. Thanks for all your observations and advice : )

So (more questions : )
What is the difference with internal setup of DV injectors and what will the effect be when using them in my DW engine with DV settings as opposed to the correct settings? Short term / long term - performance, fuel economy etc. Mainly though; will it damage anything?

I guess all of the different settings are defined by the shims above the spring and hence the spring pressure / tension?

Last edited by blix99; 04-23-2020 at 04:07 AM.
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  #12  
Old 04-24-2020, 10:16 AM
ngoma ngoma is offline
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Quote:
Originally Posted by blix99 View Post
I guess all of the different settings are defined by the shims above the spring and hence the spring pressure / tension?
Yes the various shims thicknesses are used to create the necessary spring preload force on the nozzle pintle for the desired POP pressure. That and the nozzle (pintle and orifice) shape and design determine the spray pattern. Also affect ultimate timing.

What nozzles (Bosch P/N) are in your new injectors?
Stock nozzle for D24T is Bosch DN 0 SD 1930 (USA/Canada), DN 0 SD 293 (other markets)

What is DW/DV?
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  #13  
Old 04-25-2020, 02:29 AM
blix99 blix99 is offline
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Hi again.

Thanks again for the reply.

I'm not sure of the nozzles in the new injectors as they are fitted now and would also require taking them apart to see.

It might have been on the box but I had to exchange with my old ones and that required sending them back in the boxes. I took a few photos. I'll see if it says (they are on my phone)

DW and DV are the engine types. From Wikipedia regarding the VW LT van:

Quote:
2.4 D24 I6 2,383 cc indirect 55 kW (75 PS; 74 bhp) @ 4,000 rpm 155 N⋅m (114 lbf⋅ft) @ 2,800 rpm CP: 08/78-11/82, DW: 12/82-07/92

2.4 D24T I6 2,383 cc indirect, turbo-charged 75 kW (102 PS; 101 bhp) 195 N⋅m (144 lbf⋅ft) DV: 12/82-07/92
So, DW is what I have - straight six non turbo. The injectors I bought were for the DV engine - more or less the same but with the turbo

Last edited by blix99; 04-25-2020 at 02:32 AM.
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  #14  
Old 04-25-2020, 07:45 AM
v8volvo v8volvo is offline
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Based on what you have said, it sounds like the difference between the DW and DV is the same as what we would think of as the D24 and D24T, but expressed in VW engine codes rather than Volvo codes. In that case the only difference is likely the "pop" pressure calibration of the injectors -- 130 bar for the naturally aspirated D24/DW and 155 bar for the D24T/DV.

The higher pressure turbo spec injectors will run just fine in the non-turbo motors. The extra injection pressure is mainly needed in order to overcome the higher initial combustion chamber pressure in the cylinders of the turbo engines when the turbo is delivering full boost pressure. The higher injection pressure is not necessary in the non-turbo motors, but it certainly will not damage anything at all, and most likely will make no noticeable difference of any kind.

Buying the Bosch reconditioned injectors sounds like it was a good move. I have installed a few sets of those with good results. Bosch seems to do a reasonable job with quality control on them, at least that was the case as of my last encounter. I used to sometimes test batches of their recon injectors before installation using a cheap DIY-grade pop tester and most of the injectors out of Bosch boxes were right on, a few a little high or low, but they were probably at least as good as many fuel injection shops might produce. In theory a set redone by a really good independent fuel injection specialist might be best of all, if done very carefully by someone with a lot of experience and attention to detail and plenty of time available to spend on them, but as you point out, it could just as easily be hit or miss with that, if working with a shop you don't already know well and have confidence in.

The only small but noteworthy implication of running the higher pop pressure turbo spec injectors is that the actual in-cylinder "start of injection" (SOI) timing will be retarded slightly, versus where it would be with the same set of injectors at a lower pop pressure. This is because it will take maybe another degree (or perhaps a fraction of a degree, who knows) of rotation of the fuel injection pump, and the engine, in order for the pump plunger to build enough pressure to pop the injector open and begin injection. So, in theory, you might find with the new injectors that cold weather starting and power and fuel economy see a small negative effect. If you do find that, you could advance the injection pump timing very slightly. You have been through that process now so you know it's not too difficult once you have the hang of it!

However, you may also find there is no noticeable difference. This effect of injector opening pressure on in-cylinder timing is real, but it would take a lot of complex engineering calculations to know exactly how significant it is, and it may be that it's miniscule at the pressure difference you have here, or if measurable it may still be well within the acceptable range. If you are happy with the way the engine starts and runs, and with the mileage, then there's no reason to worry about it. Just raising it since you were wondering what *possible* effects might be seen from the turbo injectors in the non-turbo engine.

Nice photos of your van, and nice work getting it up to shape for use. Hope you will get some good use of it this summer now that you have it running well! Those are neat vehicles, too bad we didn't have them here. You might have already mentioned this somewhere, but do you know the history of the last timing belt and water pump change? If not that is something you may want to consider doing before putting on too many miles.
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  #15  
Old 04-27-2020, 12:45 AM
blix99 blix99 is offline
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Hello.

I know I keep saying, 'Thanks for the reply' but I really do appreciate it as I'm learning all the time with this engine.
I'm either used to basic, old, VW air-cooled engines and some experience of newer VAG engines (I've had many newer VWs, Skodas, Seats and Audi's)

But this kind of 'middle section' of engines have passed me by : )

Anyway, thanks for all this info. I did consider the timing for greater pressure might be slightly delayed but, other than trial and error of advance / retard, over a period of time, I think, as you say, it would be almost impossible to ascertain pros and cons of running; unless it was awful and noticeable, which it isn't.

I could go nuts over this stuff. Your reassurance of no harm running these is great and I think I'll just see how it goes. It starts and idles better than it did. I've never even driven it yet, after just over two months of ownership!!

I have some welding to do for it's MOT (yearly government test for vehicle safety here in the UK) Hopefully once that's done I can drive it around and really see how it goes.

I think the timing belt / water pump will be done after this but before any serious travel - I just need to get it roadworthy first. Then I'll be pretty happy I've done what I can to make it as good as possible. It is almost 40 years old but has a mileage of around 120k, which isn't too bad and will hopefully be good enough for the time I'll have it.

Also, after all this I still have to rebuild the camper part; inside and out - re-framing, re-wiring, re-plumbing and on and on ...

I'll get there.

Cheers
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