D-Jet Injector Maintenance and Service Notes

Nov 2023 R Kwas [Comments Added!]

Routine Maintenance/Good Practice
Injector Maintenance
Injector Service
    Injector Leaks

Reference Information
    Injector Hose Replacement

Injector Mounts, Sealing and Thermal Isolation

Electrical Connectors and Connections


A collection of Bosch 0 280 150 036 Injectors, in various states of dress, undress, old, and new! 


After all the sensing of operating conditions is done at the B20, and all the (analog!) signal crunching is
performed in the D-Jet ECU, this component is where the important action takes place (X4)!


Routine Maintenance/Good Practice

There is no routine maintenance called for on the D-Jet Injectors, but adding an ounce of Marvel Mystery Oil to each tank full of fuel is good practice!  Since the D-Jet fueled Volvos have no catalytic converter, there is also no risk of damaging this non-present component...however, all moving/fuel-contacting components like Injectors, even Fuel Pump, Fuel Pressure Regulator, and Valve Guides, will benefit from adding this light lubricant to the fuel! 

Injector Maintenance: 

Cleaning, flushing the internal final filter and lubing Injectors is very good practice when replacing the rubber lines (simply for age, certainly if any leakage is observed in service [see also below!] and with ethanol compatible high pressure qualified hose): 

Source:  "Super Speakers" YT video:  FAST & EASY FUEL INJECTOR CLEANING GUIDE  https://www.youtube.com/watch?v=LQ44_QyoXiM

A cropped screenshot of flushing operation (with Brake Cleaner NOT Carb Cleaner solvent IMPORTANT, see CAUTION below!, and while under [*current limited!] power from a 9V Batt, so Pintle is continuously open, which also allows checking for an even spray pattern) from approx. 6:20 timestamp on video.

* Current limited power means that Injector is NOT subjected to a full vehicle 12V (which would be VERY BAD for it! See:  Dynamic and Static Injector Test Notes  ) but something less even than 9V from a small battery whose voltage is undoubtedly also collapsing under the huge load, a ~1.3Ohm Injector coil would be putting on it(!), but since this is a fairly inexact number, if this operation is done with power from an actual Car Batt or variable bench power supply, a ~6Ohm power resistor MUST be wired in series with the car Batt, OR adjusting the bench supply V to 3 and setting the current limit to a nominal 5A will allow this operation to be performed without overstressing the Injector under test.   [The Resistance of ~1.3 Ohms was arrived at with "rounded values" here.  Precise Resistance value of Injectors is a complex and dynamic parameter...for the purposes of service described here, and simply opening the pintle for service without risking damage, using a value of ~2Ohms will do, and limiting the Injector Current during service is necessary!  See also below:  Evaluation of Test Setup shown in Video  ]

My comments to video:

"Compliments on a very good hands-on video!  In normal operation, Injectors are supplied 12V through a 6 Ohm current limiting Resistor, which drops the actual V applied to Injector to 3V (Reference), so applying non-current-limited [not really!] battery power scared me a bit at first, but I expect the V of such a small 9V Batt, connected to a near-short (of ~2Ohms Injector R), will collapse the V to something non-damaging to the Injector (I realize it is only applied for a fairly limited time, but you should emphasize this also!)...have you measured what V it collapses to? The only thing I might add is to check for an even spray pattern when doing the pressurized flush...if it is not even from around the pintle orifice, a longer soak or additional flushing is called for until pattern is even...this is pretty important and the goal of the whole process!  I also like the idea of storage-lubing the injectors after the cleaning process. Cheers  " 

See also:  Evaluation of Test Setup shown in Video below.

Since writing the above comments to video, I have added that the poster of the video should emphasize and recommend the use of non-flammable Brake Cleaner for this operation, instead of highly flammable Carb Cleaner.  I'm not Mr. OSHA, but advise the following...:

CAUTION AND VERY IMPORTANT SAFETY TIP !   The above test should be performed in a fire-safe area, using Personal Protective Equipment, extinguishing provisions immediately at hand, and preferably using nonflammable tetrachloroethylene (Brake Cleaner - smells like "dry cleaning fluid"), and NOT highly flammable Carb Cleaner as recommended by the video author!  If one were to use highly flammable Carb Cleaner, and one of the electrical connections were to come dislodged during the test, there would be spark generated because of breaking the current through the inductive Injector, which would easily ignite the atomized carb cleaner not far away, and this is just looking for a source of ignition! 

  IN ALL SERIOUSNESS:  Work Safely, and DON'T wind up like Jay Leno!  Observe fire prevention techniques!

Jay says (paraphrased!):  "Don't light yourself up!...been there, done that!...visited the Hospital Burn Unit!"

Reference:  https://en.wikipedia.org/wiki/Tetrachloroethylene


Injector Service:

At this point (age and/or mileage), if Injectors have never been serviced, it is probably a good time, when they are off the engine for cleaning/flushing, to change the Fuel Supply Hoses.  These hoses are sealed with hose-barbs on the Injectors, and because of the high pressure, an additional crimped-on ferrule, but it is not uncommon for this seal to be compromised (see Injector Leaks below!).

Replacement Supply Hose Kits are available, see:  https://injector-rehab.com/product/hose-end-injector-rebuild-kit/  ...also Reference Information below!


1.  After Disassembling Injector from Fuel Rail, remove old Fuel Supply Hose, and replace with new (ethanol compatible), using approved Clamps.
2.  Clean/Flush/Lube Injector
3.  Reinstall in Injector Holder, and into Cyl Head, with new Sealing Rings and Optional Thermal Isolator Washers (particularly if the car's service area is in warm climate, where Hot-Start after Heat-Soak is noticeably difficult).
4.  Charge Fuel Rail (power Ignition ON), and check for leaks.



Injector Leaks

My response to Swedespeed Thread:  Leaking Fuel Injector 1971 1800E "1-2 small droplets every second" https://www.swedespeed.com/threads/leaking-fuel-injector-1971-1800e.672578/  ...in which poster also included this pic: 

Picture used by permission of "Foxikins", who says:  "...no need to attach my name".

Injector exhibiting fuel leakage with puddling, so in need
of some immediate service, but not necessarily replacement!

"Deterioration of coatings in the lower area is obvious and indisputable, but I don't believe it has much if anything to do with the leak, which from the first pic, is clearly way above that, and so more likely at the supply hose to Injector interface hose-barb/crimp, and this is not unusual, given the age of the components.

30PSI is present in the supply Rail any time the Fuel Pump is powered, and even after it is depowered (until it leaks down!), and these shorty hoses which are a "permanently" crimped-on part of the Injector must seal against this pressure. These hoses do deteriorate with age, but replacement of the entire Injector is not the only solution. Kits are available for replacing just these hoses...I have bought such a kit with which to redo all four Injectors, but have not yet undertaken and documented the operation.

I recommend Cleaning/Flushing/Lubing all Injectors while they are on the bench for renewal of the Supply Hoses...from my notes, here is a very good vid for the former: https://www.youtube.com/watch?v=LQ44_QyoXiM

...and although I have not yet done the operation, I think this video shows Supply Hose removal/renewal well: https://www.youtube.com/watch?v=0qEV0UsQGHw

Source for the hose kit I got was:
Hose End Injector Rebuild Kit [See also Reference Info below!]

Disclaimer: I have no relationship with any of these links, and give this info strictly as help. Work carefully, and let us know how you make out or other hands-on details...

When installing Injectors back into Cyl Head, use new Seals, or at least seals ones which have been checked and verified not to have lost their compliance and turned rock-hard (to prevent vac leaks), and install thermal isolators washers on Injector mounts if you are in a geographical (hot) area where hot-starting after heat-soak is particularly difficult! [See:  Injector Mounts, Sealing and Thermal Isolation below!]

I expect that will address your fuel leak, and significantly improve your gas-mileage!"



Reference Information: 

X-Ray drawing of Injector based on the factory green manual, with some additions for clarification: 

Purpose of the Pintle Cap as a protector of the otherwise protruding and vulnerable Pintle, should be clear from this view.  See also:  Injector Details below.


Removing and replacing FI Supply Hose:  

I have seen advice based on cutting a slot into the Sealing Ferrule first, with a small cut-off disc, and removing it, to relieve its compression force, then cutting the hose from the hosebarbs.  In this vid, the operator simply cuts the hose and literally wrenches it off the barbs with Significant Wrenching Force... 

When I perform the operation (see:  Injector Hose Replacement  ), I will decide and advise if the SWF technique is OK to use, or if it is too violent and abusive on the Injector, and to be avoided...


Removal of Fuel Supply Hose from Injector using SWF!


Replacement Injector Hose Kit:  


Kit includes all wear-out items, including Pintle Caps.

Checking pedigree of the hoses included in kit:

Hoses included with kit are Gates 42XXXX ...see following info!, indeed high pressure and ethanol qualified!...the six hoses on which printing was visible are shown, the two remaining of the 8 total I purchased, had no visible markings.     


Update:  I contacted Mr. Gibbons about completing the Gates number, which he confirmed to be 27340 Gates Barricade (the 42196039 number is a "Product #" according to Product Details), and I asked if there was any recommended procedure/instructions for replacing the hose.

From the Gates site:  https://www.gates.com/us/en/fluid-power/engine-hose/fuel-line-hose.p.4219-000000-000003.v.4219-06039.html


As far as the recommended procedure/ instructions for replacing the hoses, he gave this link:  https://injector-rehab.com/frequently-asked-questions  where I see the following two particularly interesting bits of info I've extracted, among others: 


Further, all he could suggest was: 

"The instruction would be the same that comes with new underwear. 

Take the old crappy ones off. Put new ones on."


...so I pointed the following out to him: 

"Thanks for info, but those instructions might be oversimplified!  [...besides the fact that I've never even seen instructions with new underwear!]

For some people (not necessarily me!), you'd have to specify standing on one foot alternately to facilitate taking the "old crappy ones" off, and also to put the new ones back on, with the label toward the back (and inside!), with the legs going into the two smaller of the three holes...the presumption being that they would remember the alternate foot thing when putting them on...analogous to "Reassembly is the reverse of disassembly." as Mr. Haynes would say in his manuals. 

R "

He wrote back thanking me for the tip!


Injector Hose Replacement:  

"Injector Day" at the Swedish Embassy: 



Removal of old Supply Hose: 

Removing swaged-on ferrule with SWF.  Doing this operation the hard way and with only a knife to cut the hose, and heavy duty side-cutters to nibble away at the ferrule, took 5 minutes per injector, and is pretty "rustic and violent" as seen in the pic...its not so much fun, and the hose fitting and barb are vulnerable, but removal is doable! ....carefully cutting it with a micro-cut-off disc would be a lot less violent and quicker way to proceed! 


Checking for free Pintle:

Using a pointed wooden (chop) stick to check if Pintle is free to move.  Even when not stuck and free to move, actual displacement is a mere 0.006" (0.15mm), so takes care and a sensitive hand to detect.  A drop of Tri-Flow or MMO seeps in when it is moved.  


Injector Details: 

A retired Injector with a broken away Pintle Cap allows a close inspection of the protruding Pintle.  Close inspection of its hourglass shape explains the conical shape of the shower of fuel when it occurs in service.  A tool presses on the Pintle and confirms dimension D is a mere 0.006" (0.15mm).  The number "3" is evident multiple times in a depression in the housing.  I expect this may have been identification mark of the base casting for internal Bosch manufacturing tracking purposes.  Actually, since PCs are included with the above shown Kit, this Inj could be rebuilt and checked for possible return to service.     


Evaluation of Test Setup shown in Video:  

Test Setup:

Test and cleaning set-up, using a 9V Batt connector wired to 0.125" fast-on connectors.  Unloaded V of a fresh 9V Batt before the Injector under test is connected, is measured at a healthy 9.3V, and Resistance of test Injector was measured at 2.1Ohms. 


Injector under test, powered:

Once Injector under test is connected, an audible click is heard (or should be, as Armature slams into its endstop, if Injector Armature is free to move, and not bound up!) and Batt V collapses to 3.6V due to the high current the Inj is drawing:  1.7A (3.6V / 2.1).  At this time, the flushing/lubing operations shown in the vid, could be performed.

If no click is heard, it means that Armature is bound up and Pintle is not moving/opening normally...connecting and disconnecting the power to subject Inj to some mechanical shock/impact might help at this point...otherwise a drop of Marvel Mystery Oil into the fuel feed and allowing it to soak for a week, before retrying the test and flush, is recommended.  Using a soft-tipped tool to press on the Pintle while a drop of MMO is applied externally, might also encourage it to free up...   

Explanation of "Voltage Collapse":   1.7A is a very high level of load Current for such a modest sized Batt (confirmed by the massive V collapse from over 9 to under half that, caused by internal Resistance of Batt!), so it is a safe and acceptable test here, but when used on four Injectors, the poor Batt will be spent and ready for retirement after the tests...but again, the crucial requirement of not subjecting an Injector directly to a high Voltage and resulting Current, is satisfied due to the V collapse. 

By comparison, Voltage of a car Batt, which is happy, capable, and intended, to supply huge Currents, would not collapse in this manner, so it could NOT be used directly, and without a current limiting provision, to power Injectors, and so has these current limiting Resistors internal to ECU, or would require a similar provision if used for the test and service of Injectors. 

See also:  https://learn.sparkfun.com/tutorials/measuring-internal-resistance-of-batteries/internal-resistance


Injector Mounts, Sealing and Thermal Isolation:

Differences in Injector retaining, early to late production, without Pertinax washers and small dia O-Ring vs. 2 Pertinax Washers and larger cross section O-Ring (to seal with the additional height of the Pertinax thermal isolator washer under Injector Mount). 

Source:  https://www.v1800.org

PLACEHOLDER FOR TRANSLATION  Essentially, it shows the earlier style, with no provision for thermal isolation, and the later (retrofitted) style, intended to reduce/slow thermal conduction from Cyl Head into Injector(s), which can result in difficult hot-starting. 


Electrical Connectors and Connections: 

The state of D-Jet electrical connections from Sensors to Injectors is inarguably critical for reliable service.  Inspecting these and keeping them in good condition is vitally important!

An example of a "Before" condition which needs attention!  Frédéric Nolleau picture, used with his kind permission.

What this owner found at an Injector...he said his mechanic didn't "like" the look of those connections [I don't so much either!]...it looks like someone has replaced the oe connector with standard 0.125" crimps (very much-like I used for the bench test set-up, shown above), fine on the bench, and even maybe in a pinch on the car, but it doesn't look like they did a very nice job in the process of crimping...in-fact, they look terrible!  Connections which look like this, can only reward the owner with reliability problems...!  See:  https://www.sw-em.com/Wiring%20Notes.htm#Makin_a_Proper_Crimp


Frederic noted he ordered replacements from a German supplier.



External material sources are attributed.  Otherwise, this article is Copyright © 2023-2024.  Ronald Kwas.   The terms Volvo, Bosch, and names of other suppliers shown here are used for reference only.  I have no affiliation with any of these companies other than to keep their products working for me, help other enthusiasts do the same, and also present my highly opinionated results of the use of their products here.  The information presented comes from my own experience and carefully considered opinion, and can be used (or not!), or ridiculed and laughed at, or worshipped, at the readers discretion.  As with any recipe, your results may vary, and you are, and will always be, in charge of your own knuckles, and future! 

You are welcome to use the information here in good health, and for your own non-commercial purposes, but if you reprint or otherwise republish this article, you must give credit to the author or link back to the SwEm site as the source.  If you don’t, you’re just a lazy, scum sucking plagiarist, and the Boston Globe wants you!  As always, if you can supply corrections, or additional objective information or experience, I will always consider it, and consider working it into the next revision of this article...along with likely the unique metaphor and possibly also wise-a** comment. 


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