Injector cleaning - my experience

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PeteE30Tourer
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Post Wed Nov 16, 2005 6:44 pm

At long last, i got around to putting in the spare set of injectors that i'd had ultrasonically cleaned and tested. Just thought i'd share my experience with you all.

Firstly, the set of injectors came from Scott's car that had a reported 112k miles on the clock, so i was expecting them to be pretty clogged up. After all, the injector cleaning people said they should be done every 40k miles. However, the report i got back with the cleaned injectors showed that the differences between the "before" and "after" were minimal. Before cleaning, they were tested for leaking (all ok), spray pattern (all good) and M/S-RPM (not sure what this is, but they all passed). The measured flow rate was 70 on all but two that came in at 69. After cleaning, the only difference on the report was that they all made 70 on the flow rate, so not a massive improvement on paper for my Ԛ£92.77 including VAT + P&P!

Anyway, here's a couple of pics of one of the old injectors that came out of my car and one of the "new" ones that went back in - see if you can guess which one is which!

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Fitting them to the car was a doddle, following the excellent guide that Iain (aka Templ8e30) provided here:
http://www.e30zone.co.uk/modules.php?na ... ic&t=21733. At least it would have been a doddle if i hadn't been so stupid with a cotton bud (see post elsewhere on this forum if i can be brave enough to admit to it!).

Whilst i had the car in bits, i also did a few other maintenance jobs, i.e.:

- cleaned out AFM with carb cleaner
- cleaned out ICV with carb cleaner
- sealed all hose to metal seals with a bit of silicone sealant
- changed the oil/oil filter

I also had to take the entire inlet manifold off due to the incident with the cotton bud, so that was all re-sealed too.

So, what was the end result of this 5 hours hard labour??

Not a great deal i have to say!

The noticeable differences are:

1. Car idles far more smoothly now - gone is the brroom-brroom-broom tractor noise it used to make at idle

2. Pick up from idle is much worse - i have to give it quite a bit of revs before dropping the clutch, especially when cold

3. The excessive exhaust smell i had appears to have gone, though this was made better by raising the CO from 0.1 to 0.8 by adjusting the AFM previously.

4. Acceleration or take-up in gear doesn't seem to be any worse or better.

5. The car is a little quieter to drive - the ticking isn't quite as bad as it was, but it's definitely still there.

The thing is - any of the above could be down to any one of the things i've done. With hindsight, it would have been better to do one thing at a time to see what had which effect. However, i dont get much time to work on the car so this wasn't really feasible.

All in all, i'm quite disappointed that all that effort and money made so little difference. I'm yet to see what's happened to my mpg, which has always been around 21 to 23, so perhaps that will improve. I'd also like to get the CO checked again now that the injectors have been cleaned, all the air intake side has been sealed and the AFM & ICV have been cleaned out. Perhaps that will make a difference now.

Any thoughts on this?
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Davenotouring
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Post Wed Nov 16, 2005 6:54 pm

Just echoing what you've said really Pete.

Bit suprised, because visually you'r expect much more of an improvement.

Shows that these things are designed to do the mileage and their performance doesn't actually deminish as much as you might expect!

Top work Pete.

Anything which gets rid of the 'Bub bub bub' at idle is worthwhile by me. That is very annoying!!

:D
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SCOTT325SE
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Post Wed Nov 16, 2005 7:52 pm

PeteE30Tourer wrote: Firstly, the set of injectors came from Scott's car that had a reported 112k miles on the clock
121k actually fella. prolly a typo, but just for the record.
Adammcf
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Post Wed Nov 16, 2005 9:30 pm

I was toying with the idea of getting mine cleaned before I put them back in but I might not bother now.
JOSEMI
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Post Wed Nov 16, 2005 9:35 pm

Good info, I guess after all the money spent that becomes a job off the list, as davetouring said at least gets rid of the annoying noice that they used to make, which is good enough (mine makes that noise and wondered how to get rid off before I read your report)

Good to know how they look too, I had never seem them before

Jose
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Post Wed Nov 16, 2005 9:52 pm

The mpg improved a bit on mine and the acceleration but the rough idle got worse. :(

I still haven't got round to checking the dizzy cap so i'm not writing it off as a loss just yet. (fingers crossed)
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JOSEMI
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Post Wed Nov 16, 2005 9:54 pm

yeah, the caps... sounds familiar, they don't last long (in my car) the buggers

Jose
Adam318i
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Post Wed Nov 16, 2005 10:07 pm

- cleaned out AFM with carb cleaner
- cleaned out ICV with carb cleaner
Can anyone tell me how to do these?, noob question i know.

I have a 1.8 M40 for the record.

PM me if you like.

Adam
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Andy335Touring
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Post Wed Nov 16, 2005 10:52 pm

When i had my old M30 injectors cleaned i noticed hardly any differance :(

But it just means they wern't to bad before i guess ?

This is the before and after injector flow report i got

http://img453.imageshack.us/img453/8282 ... 0380ny.jpg
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Bimmer8604
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Post Thu Nov 17, 2005 4:34 am

I'm in the market for getting some new injectors, and theres a company that does the whole sonic cleaning stuff, and sells them for almost half the price of what a normal set of used injectors cost. I think I'm better off spending that 50 dollars on some beer or something. Thanks for doing a comparison!

Kyle
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Post Thu Nov 17, 2005 6:21 am

Adam318i wrote:
- cleaned out AFM with carb cleaner
- cleaned out ICV with carb cleaner
Can anyone tell me how to do these?, noob question i know.

I have a 1.8 M40 for the record.

PM me if you like.

Adam
i would be interested in this as well, is there any walk through etc.
i have a 2.5 M20
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PeteE30Tourer
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Post Thu Nov 17, 2005 8:26 am

The other thing i forgot to mention is that the car starts right on the button now rather than after 2 or 3 seconds before. After driving the car a little more last night, i'm beginning to think the car is a bit more free-revving, but the difference is very minimal.

As for cleaning out the AFM and ICV, just take them off and spray loads of carb cleaner into the orifices. With the ICV, I sprayed loads in one end whilst blocking off the other end, then blocked both to give it a good shake with the carb-cleaner insider, then drain it out. Repeat several times until the fluid comes out clear - takes a surprising number of times to achieve this. Similar process with the AFM too - it's just a case of cleaning all the grime off the moving parts to ensure they can move freely in operation.

As for buying new injectors - i believe they're about Ԛ£80 each from the dealer - that's the best part of Ԛ£500 for a 6-pot. I bought a second hand set for Ԛ£15 and paid just under Ԛ£100 to get them cleaned - a considerable saving over new.
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