Off-vehicle injector cleaning - worth it for PM?

Status
Not open for further replies.
Joined
Sep 24, 2005
Messages
1,008
Location
Indiana
I've read about people removing their fuel injectors and having them cleaned/reconditioned by specialists. I'm wondering if it is something to consider for a vehicle that isn't exhibiting problems, but may be old and/or high mileage?

The cost of the service doesn't seem prohibitive at all, and I have read accounts where PM like this (or even replacing a MAF, preemptively) made a significant improvement.
 
It wouldn't be worth the hassle unless you are experiencing problems. If you must, run some Techron or other injector cleaner through the fuel tank. You could potentially cause issues by taking something apart that is working well.
 
I would say if fuel mileage, cylinder balance and low end torque are good ....

The would be absolutely no need.

I've had injector damage by bad fuel on ford 4 cylinders where they never recovered.
I just traded the vehicle.
 
Put this square into the FWIW category.

Several years ago my aging 911 was exhibiting some high load/high rpm misfire. During the diagnostics for that I pulled out the injectors and sent them for cleaning. At the time, the car was 27 years old and had ~145k miles on it. During my ownership it always got BP or Shell premium fuel. (ETA: I did also use Redline SI-1 every 12-18 months)

The injector cleaning service found them to be in-spec, and while the cleaning did improve the spray pattern some there was no real change in their fuel delivery when compared to before cleaning.
 
Last edited:
It depends on a lot of things. Some injectors have bad filters inside that no amount of in tank or rail chemicals will get rid of, the filter must be replaced, the only thing that happens is the deposits get pushed through into the injectors.
Some old style units are made of iron and brass and are prone to corrosion when used with ethanol laced fuels. Some DI injectors actually burn the filters right out and drop particles down into the nozzles.

There is no single answer to your question. Tell me the year, make and model and engine info and I can give better info.

This is an example of a clogged filter, they tried to clean them through the rail, it didn't work. The flow was poor at best, new filters and a good cleaning brought them back to 100%. Lack of primary fuel filter maintenance and dirty fuel can contribute to this.
[Linked Image]


An example of a very expensive DI unit, these need to be dismantled to access the filter under the nozzle, not a cheap job but 1/4 the price of a new one. This engine no longer ran on all cylinders.
[Linked Image]

[Linked Image]

[Linked Image]
 
FWIW, years ago I had a 1998 Maxima that developed a problem that sounded like a classic leaky fuel injector. It would start then immediately die, then require a couple of seconds of cranking and start with a cloud of black smoke.

I took it to a mechanic who did some kind of fuel injector clean on it and it totally fixed the problem.
 
Originally Posted by Trav
It depends on a lot of things. Some injectors have bad filters inside that no amount of in tank or rail chemicals will get rid of, the filter must be replaced, the only thing that happens is the deposits get pushed through into the injectors.
Some old style units are made of iron and brass and are prone to corrosion when used with ethanol laced fuels. Some DI injectors actually burn the filters right out and drop particles down into the nozzles.

There is no single answer to your question. Tell me the year, make and model and engine info and I can give better info.

...



Primarily, I was wondering about my 1999 528i (120k miles). Engine seems to run fine (at least as well as it did when I bought it with 80k). I try to do as much PM as possible (ie: cooling system, belts, etc.). The car does see periods of little use and the fuel doesn't get used up like a daily driver, that's for sure.

P.S. Thanks to all who've weighed in.
 
Last edited:
Originally Posted by Trav
It depends on a lot of things. Some injectors have bad filters inside that no amount of in tank or rail chemicals will get rid of, the filter must be replaced, the only thing that happens is the deposits get pushed through into the injectors.
Some old style units are made of iron and brass and are prone to corrosion when used with ethanol laced fuels. Some DI injectors actually burn the filters right out and drop particles down into the nozzles.

There is no single answer to your question. Tell me the year, make and model and engine info and I can give better info.

This is an example of a clogged filter, they tried to clean them through the rail, it didn't work. The flow was poor at best, new filters and a good cleaning brought them back to 100%. Lack of primary fuel filter maintenance and dirty fuel can contribute to this.
[Linked Image]





Q: Are DI injectors becoming unservicable?
 
Last edited:
These are an older style long pintel Bosch unit. They are definitely dirty and effecting performance, you just don't feel it as they all get dirty and keep running smoothly. People usually attribute this to the engine is "just getting old" but in reality, if the compression is good and the engine is in good shape there is no reason for reduced power.

I usually get quite a bit more flow out of these, you notice it at higher rpm's. These are yours, the first picture is 3 cleaned and 3 as they came in, the second are the finished ones. I got about 20% more out of a few and all had a better spray pattern.

[Linked Image]

[Linked Image]
 
Last edited:
Hmm, makes me wonder. My '99 5S-FE has always had a wonky idle, a rough one, that plugs didn't fix--but it's done that for 80k and has happily chugged along. Albeit only at 31mpg, seems a bit low. Bought used so I have no idea if it's lost power or not (I don't think it ever had much to begin with).

Quick look seems to come up with Denso 23250-74100; don't need CA emissions. https://www.injectorplanet.com/products/denso-1955005580

I think my laptop still works, so I might have a working version of Techstream. I should poke around and see if I can find injector balance, not even sure what it'd be under.
 
Regardless of who does the cleaning I advise against getting re hash jobs, clean yours instead. These guys buy them in barrels and dig like ones out, some may have low miles and others high. Cleaned up they work but the cores can be sketchy.
I rather dig a set from the bone yard that has lower miles and still wet with fuel and clean those if the ones in the car are very high milers or defective for some reason.
 
I have two sets of injectors for every vehicle I own; the factory set and a flow matched set. As part of preventive maintenance, whenever I do a tune up, the old injectors are packaged and sent to Trav for cleaning and inspection. He cleans them on an ASNU machine, replaces the basket filters, individually inspects the injectors for flow and spray pattern, seals them up for storage, packages and mails them back to me.
 
Originally Posted by spasm3
Trav, have you seen many of the mazda DI injectors needing service? I have the 2.5G non turbo.


I have and some have been very surprising, on these and some VW/Audi models especially I have seen the filter baskets totally burned out leaving just a brass ring where the filter used to be. I posted pictures some months ago of this.
The other issue with DI is the Teflon rings get burned, for this reason alone nothing you do as preventive maintenance can prevent it an no cleaner can remove burned nylon particles, they need to come out the same direction they went in.
 
Originally Posted by BMWTurboDzl


Q: Are DI injectors becoming unservicable?[/quote]

Not really, the technology is moving to Piezoelectric units and some filters are being installed upside down inside like in the big DI injector I posted the pic of but fortunately they are stainless and can be cleaned. Seals are at the moment are scarce for some and must be bought through a dealer and can be quite expensive but a lot cheaper than a new injector eg one set I did was almost $600 per x 6, cleaning was $50 ea and the seals for each one was $70. So $750 inc $30 post, no sales tax vs $3600 plus tax and post is a significant savings, they ran perfect.
 
Originally Posted by Falcon_LS
I have two sets of injectors for every vehicle I own; the factory set and a flow matched set. As part of preventive maintenance, whenever I do a tune up, the old injectors are packaged and sent to Trav for cleaning and inspection. He cleans them on an ASNU machine, replaces the basket filters, individually inspects the injectors for flow and spray pattern, seals them up for storage, packages and mails them back to me.


This is the idea I originally posted about. I've read a number of accounts of situations like Trav mentioned - degraded spray pattern, matching, not causing poor operation but enough to make the owner just figure it's "an old engine". I also mentioned the MAF. I've seen video's of a guy with an M5 that they did a dyno run on - it was was making about 15% below expected power but not running terrible or setting codes. They disconnected the MAF, did another run, and saw improvement with the engine using failsafe mappings. Then they put a new MAF in and saw even better performance.

I've considered doing it with my BMW because of it's age and tendency to sit (truly a "garage queen"). Being an inline 6, getting at the fuel rails/injectors/intake appears to be reasonably easy given the layout. Unless something has changed, the cost for the service seems quite reasonable (very minor compared to a lot of the "upgrades" some add on older cars). The biggest issue seems to be having the car out of service for a week or so (and having to pull and replace the injectors).

To Trav: you mentioned "rehash" job. I assume you meant to get your injectors cleaned and returned, not a trade like a reman/core purchase. BTW it appears my car uses a Siemens/VDO injector (current P/N A2C59511971) - what would be the price to recondition (6) of them?
 
Originally Posted by Touring5
Originally Posted by Falcon_LS
I have two sets of injectors for every vehicle I own; the factory set and a flow matched set. As part of preventive maintenance, whenever I do a tune up, the old injectors are packaged and sent to Trav for cleaning and inspection. He cleans them on an ASNU machine, replaces the basket filters, individually inspects the injectors for flow and spray pattern, seals them up for storage, packages and mails them back to me.


This is the idea I originally posted about. I've read a number of accounts of situations like Trav mentioned - degraded spray pattern, matching, not causing poor operation but enough to make the owner just figure it's "an old engine". I also mentioned the MAF. I've seen video's of a guy with an M5 that they did a dyno run on - it was was making about 15% below expected power but not running terrible or setting codes. They disconnected the MAF, did another run, and saw improvement with the engine using failsafe mappings. Then they put a new MAF in and saw even better performance.

I've considered doing it with my BMW because of it's age and tendency to sit (truly a "garage queen"). Being an inline 6, getting at the fuel rails/injectors/intake appears to be reasonably easy given the layout. Unless something has changed, the cost for the service seems quite reasonable (very minor compared to a lot of the "upgrades" some add on older cars). The biggest issue seems to be having the car out of service for a week or so (and having to pull and replace the injectors).

To Trav: you mentioned "rehash" job. I assume you meant to get your injectors cleaned and returned, not a trade like a reman/core purchase. BTW it appears my car uses a Siemens/VDO injector (current P/N A2C59511971) - what would be the price to recondition (6) of them?



Is your BMW the DI variant? If so, then you may want to consider buying the tool used to extract the injectors as they can sometimes break upon removal when doing it by hand. My two cents.
 
Originally Posted by Touring5
Originally Posted by Falcon_LS
I have two sets of injectors for every vehicle I own; the factory set and a flow matched set. As part of preventive maintenance, whenever I do a tune up, the old injectors are packaged and sent to Trav for cleaning and inspection. He cleans them on an ASNU machine, replaces the basket filters, individually inspects the injectors for flow and spray pattern, seals them up for storage, packages and mails them back to me.


This is the idea I originally posted about. I've read a number of accounts of situations like Trav mentioned - degraded spray pattern, matching, not causing poor operation but enough to make the owner just figure it's "an old engine". I also mentioned the MAF. I've seen video's of a guy with an M5 that they did a dyno run on - it was was making about 15% below expected power but not running terrible or setting codes. They disconnected the MAF, did another run, and saw improvement with the engine using failsafe mappings. Then they put a new MAF in and saw even better performance.

I've considered doing it with my BMW because of it's age and tendency to sit (truly a "garage queen"). Being an inline 6, getting at the fuel rails/injectors/intake appears to be reasonably easy given the layout. Unless something has changed, the cost for the service seems quite reasonable (very minor compared to a lot of the "upgrades" some add on older cars). The biggest issue seems to be having the car out of service for a week or so (and having to pull and replace the injectors).

To Trav: you mentioned "rehash" job. I assume you meant to get your injectors cleaned and returned, not a trade like a reman/core purchase. BTW it appears my car uses a Siemens/VDO injector (current P/N A2C59511971) - what would be the price to recondition (6) of them?


Exactly clean what you know are functioning, you end with a better result than a bunch of different mileage cleaned units. These particular Siemens/VDO injectors IIRC use the Bosch internals and may possibly be rebadged. The Siemens units are generally plastic and VDO doesn't make injectors (I honestly don't know if they ever did, they were more of a gauge manufacturer) just buys and rebadges like SMP, not necessarily a bad thing, some of the SMP units are pretty decent and even some OE.
 
Status
Not open for further replies.
Back
Top