[a4anurag]

With the car on the other side of 1,00,000 kms, issues have started cropping up slowly. The lower arm bushes need a change, the engine sound and feel is going downwards. There is a sort of knocking/'missing-like' sound when on medium load.

At idle or higher RPM no change in performance. FE is also the same as I used to get. Timely service etc but that sound at medium load made me think it could be the injectors that are clogged. Used Adon-D and System-D for 3 to 4 full tanks but no much use. So decided to look up the internet to see if there is any solution. Browsing, I found couple of videos where Liqui Moly Diesel Purge was used for better results. I too thought of giving it a try and placed an order for it on Amazon.in (₹741 is what I paid).

Started discussing with BHPian interc00led for what and how to go about this issue and process to use the Diesel Purge!

Saw a couple of videos on YouTube for using the Diesel purge.

Liqui Moly Diesel Purge (video by Liqui Moly themselves

DIY using Diesel Purge by a VW owner

After looking at these videos, interc00led exclaimed saying that process works for VW engines and not the MJD/DDiS plus what is done in the video is actually not safer because it is by-passing the fuel filter. So we then started thinking how to do it.

Parallely, during this, was in conversation with Parag Sachania and Leoshashi for suggestions and methods to solve the issue. Also because Parag too was facing the same in his Ertiga, would be of help to us both at the same time. Sincere​ thanks to both of them for being in constant touch.

After a day's discussion, we concluded that the process flow must be the same in the way the regular flow is just that we will need a spare fuel pump to act as a source to pump diesel + purge mix into the injection pump that'll send that mixture into the fuel rail and into the injectors.

Got in touch immediately with my FNG and good news was there waiting for us. An accident vehicle that had come for repair was there so the fuel pump from it could be used.

[a4anurag]

Uploading the basic schematic on how the system works


Source: Google
_____________________________________________

Before going into using the diesel purge we wanted to check how each injector is functioning and how blocked or clean it is. This test will also give us an approximate idea how well the Diesel Purge has worked.

So we did the Fuel Injector Return Flow Test

Apparatus needed

1. Test Tubes x 4
   
   
2. Fuel Pipes x 4 (used in bikes)
   
   
3. 250 ml measuring cylinder

Test Tubes + Fuel Pipe


Measuring Cylinder


__________________________________________________ _________

Process for this is simple

Step - 1: Get a set of 4 fuel pipes and 4 test tube's for this test;

Step - 2: Disconnect the return line from each injector, be careful not to use a lot of force (they are delicate);

Step - 3: Connect the fuel pipes (Step 1) into each injectors return line;

Step - 4: Insert the test tubes and start the engine and let it idle for 1 minute.

Step - 5: After completion of 1 minute, stop the engine and measure the quantity of diesel obtained in the test tube from each injector and Record.

We are done!

Images of the Test:

Engine cover removed


Injector Return lines marked


Fuel pipes inserted in each injector return plug


Quantity of diesel obtained in test tubes


Post measuring using the cylinder


Results and Observations:

Looking at the quantities it was concluded that Injector No. 3 is the clogged the most followed by No. 4, No. 2 and lastly No. 1.

The cleanest one being I think is No.1 and worst is No. 3.

[a4anurag]

Diesel Purge Test

Initially we thought of disconnecting the inlet and return lines from the injection pump and putting it into the bottle of diesel purge but that will not work as the injection pump cannot generate enough pressure required for the Purge to work. The injection pump will function when there is a constant pressure feed into its inlet that will then amplify and send it to the rail pressure and injectors. Hence the need for a spare pump was necessary (please correct me if I am wrong, noob in these areas yet).

So the process we followed was:

Step - 1: Disconnect the battery and remove it from the car for easy working around the fuel filter area. Get a spare functioning fuel pump and place it in the bucket with 1-2 litres of diesel.

Step - 2: Make a temporary connection using wires and crimp connector so the fuel pump can be run using the battery while the purging is going on;

Step - 3: We found two salvaged fuel lines, cut it to required length, cleaned it thoroughly with Diesel and pressurized air before using (VERY IMPORTANT);

Step - 4: Disconnect the hoses coming the car's fuel tank to the fuel filter and connect the fuel lines that were prepared in Step - 3.

Step - 5: Change the fuel filter (IF older than 10,000 kms) before beginning the test.

Step - 6: Run the fuel pump circulating the diesel in it to check for any leaks and proper + continuous functioning.

Step - 7: Ascertained all good, make the final connections and secure the fuel lines properly with clamps and nylon zip ties for additional safety.

Step - 8: Pull out the fuse for the fuel pump from the fuse box located in the engine bay so the pump in the fuel tank doesn't run throwing diesel onto the engine from the pipes that were disconnected in Step - 4.

Step - 9: Crank the engine and let it idle to check for any more leaks and issues. Once all is good and functioning as it should, open the bottle of Diesel Purge and add it into the bucket containing the fuel pump.

Step - 10: Simultaneously I connected the OBD-II reader to ascertain the approximate fuel flow to determine how long the test would run to avoid issues of pump running dry causing an air lock.

Step - 11: At idle it read 0.6 litres per minute. The stock in the bucket at the start of the test was 2 litres fresh diesel and 500ml of diesel purge. So it gets 2.5L quantity of mixture. We decided to use up around 2L to avoid any air lock issues.

Step - 12: After letting the engine idle for 2 minutes, RPM was raised and maintained it at that as instructed in the video for the Diesel Purge to function correctly.

Following were the RPM's maintained during the test:

a) 1500
b) 1700
c) 1800
d) 2000
e) 2500
f) Short burst to 3000
g) Short burst to 3500

Step - 13: All the while during this test BHPian interc00led had the concentration set on the bucket and I was at the pedal ringing the engine

Step - 14: After completion of the test, we reconnected the original lines and the fuel pump fuse of my car. Started it and went for a drive.

Nirvana

[a4anurag]

Liqui Moly Diesel Purge Can


Spare fuel pump with temporary connection


Getting diesel from fuel tank prior to test start


Spare pump placed in bucket and run to check for functioning and removing any air locks


Fuel pipes getting connected...


...connected prior to fuel filter


Explaining the process by my mechanic and interc00led


Connecting the pipes and securing with clamps and zip ties


Purging going on


At idling RPM


At 2000 RPM


At 2200 RPM


At 3500 RPM


After Diesel Purge - Test tube return quantities


Measured the quantity in each test tube


While we are it anyway, opened and cleaned the intake manifold boost sensor with 100% Iso Propyl Alcohol (IPA)

[a4anurag]

Conclusion (so far after doing 100+ kms, don't flame me I know it is less driven for any conclusion)

I know it is a very small number so what i will do is give my conclusion based on what I feel post this purging activity. Shall be updating as the car clocks kilometers.

• 10 minutes into the test both interc00led and me found a difference in noise of the engine at idle. Re-assuring!
  
  
• Post the test was done, all 3 of us, interc00led, me and my mechanic went for TD. All 3 of us know what the condition was before and what it became. We were literally stunned by the results.
  
  
• Noise levels at idle better off by almost 50%;
  
  
• During acceleration the engine used to feel rough and heavy (as if something is stopping it from revving freely), this feeling is not there anymore. It revv's well.
  
  
• What the test has done is equally made the injection on all 4 as opposed to heavy difference between injectors. Combustion is better so is the FE. I'll update the FE part later as it is just 100 kms done.
  
  
• The throttle response is slightly improved post this activity.
  
  
• Have ordered another bottle of Diesel Purge which I will be adding the fuel tank and not by direct method. Will see if things improve further or no.
  
  
• Call it co-incidence or cleaning of the intake manifold boost sensor did the magic. Since purchase I don't remember seeing anything above 17 psi. Post that I have got 19.3 psi.

Total costs incurred:

Test tube: ₹ 52
250ml Measuring cylinder: ₹ 150
Fuel pipes: ₹ 44
Diesel Purge: ₹ 741
Labour: Free (But I paid ₹1,000 for the labour intensive job)
Total: ₹ 1,987

Money and time well spent!

[Jaggu]

Moving out from Assembly Line Section (More Information about this sub-forum).

Thanks for sharing and a very nice technical thread. I understand the same flush can be used as a diesel additive to take preventive action also? I think ill try this on my Thar

[Leoshashi]

Originally Posted by Jaggu

Thanks for sharing and a very nice technical thread. I understand the same flush can be used as a diesel additive to take preventive action also? I think ill try this on my Thar

Yes it can be used both as a preventive measure(using it mixed with fuel) as well as for acute issues( the way Anurag Sir did).

Regards,
Shashi

[a4anurag]

Originally Posted by Jaggu

Thanks for sharing and a very nice technical thread. I understand the same flush can be used as a diesel additive to take preventive action also? I think ill try this on my Thar

Thank you Sir for the appreciation.

It should be possible with the additive too but why I chose the diesel purge was after reading the description from their brochure:

Properties

• Boosts the cetane number
• Increases operational reliability
  
• Eliminates diesel knocking
  
• Reduces deposits
• Cleans the fuel system
• Good corrosion protection
• Guarantees optimum combustion
• Highly economical

Parts highlighted in bold made me get it and try.

[Jaggu]

Originally Posted by a4anurag

While we are it anyway, opened the intake manifold boost sensor with 100% Iso Propyl Alcohol

Attachment 1649830

Opened and cleaned with 100% IPA i suppose? ^

Originally Posted by a4anurag

Properties

• Cleans the fuel system
• Good corrosion protection
  

Parts highlighted in bold made me get it and try.

And these would work while being added in tank i guess. Read the usage details and they do recommend what you have done for aggressive intervention to injector issue

Just wondering if this is the same process the workshops do by connecting to that injector cleaner machine, and if they can use this liquimoli cleaner it would be real easy to get done. Did you think on these lines?

[a4anurag]

Originally Posted by Jaggu

Opened and cleaned with 100% IPA i suppose?

Ya opened and cleaned using IPA.

Originally Posted by Jaggu

Just wondering if this is the same process the workshops do by connecting to that injector cleaner machine, and if they can use this liquimoli cleaner it would be real easy to get done. Did you think on these lines?

No idea about MASS. I don't visit them at all. They won't take so much care and process for cleaning.

My MASS didn't care to even respond for injector cleaning when I asked.

[paragsachania]

Thanks for sharing a very detailed thread Anurag! As usual, very detailed.

Originally Posted by Jaggu

Just wondering if this is the same process the workshops do by connecting to that injector cleaner machine, and if they can use this liquimoli cleaner it would be real easy to get done. Did you think on these lines?

Jaggu, I tried this at MASS but they didn't have the Injector cleaning machine and they advised me that earlier Liqui Moly themselves had provided these Machines (authorized) by Maruti but one of the car had adverse after effects due to which they completely stopped using these set-ups.

Also, as Anurag has mentioned, for Maruti cars, the Diesel filter will not allow the cleaner to be used directly in a way that you can disconnect the pipes and dip them in the can. It doesn't get enough pressure required and hence you need to use a separate fuel pump.

In my case, I directly poured this can into the fuel filter Housing by opening it so that the next 500 ml that the car uses was this (almost undiluted) cleaner.

Results in my case were just about OK if not satisfactory. However, Since I had got the EGR and the Intake manifold also cleaned, I could seldom notice any difference
.

And before I forget, Injector cleaning is at least 4 days process - Remove, send it to Bosch for Test, collect it back and re-install. And the major irk what they (ASC) face all the times is neatly removing the Jammed injectors (if any) which they are always wary about. Not to forget that the car is at Workshop for 4 days occupying space unlike regular service cars, which will affect their KPIs as well

This method of cleaning I feel is a good route to take before attempting to clean the injectors (by removing them)

[prithm]

Originally Posted by a4anurag

Step - 9: Crank the engine and let it idle to check for any more leaks and issues. Once all is good and functioning as it should, open the bottle of Diesel Purge and add it into the bucket containing the fuel pump.

Thanks Anurag for this detailed DIY.

May I ask why the option to increase the concentration of cleaner in the fuel tank was not salvaged than this current method ?

Say if I drain the tank and fill it with 5 litre diesel + 2-3 cans of cleaner and then run the engine for few minutes with varying RPM.

Will this not work ?

[a4anurag]

Originally Posted by prithm

May I ask why the option to increase the concentration of cleaner in the fuel tank was not salvaged than this current method ?

Say if I drain the tank and fill it with 5 litre diesel + 2-3 cans of cleaner and then run the engine for few minutes with varying RPM.

Which cleaner are you talking about? Diesel purge one or the regular fuel additives?

I had almost 60+% fuel in the tank during this activity so what you said wasn't feasible at that time. Also in the Swift, tank can't be accessed from inside cabin (under rear seat). It needs to be removed from the mounting, collect that extra fuel in clean containers, then do this exercise as you said. Once completed refill the diesel. Not worth this hassle and mess IMHO. Hence I went with the route I followed.

If the car that needs this activity does have lesser quantity of fuel, then you can try doing it.

But risk factor is too high. How will you know the quantity left other than assuming? In the process​ I followed, I could see the level and judge when to stop to avoid air lock issues. Also there is a risk of heating up the pump since the quantity in the tank will be lower than the pump height. Plus there are chances of dirt being sucked from base of fuel tank due to low level which could possibly clogg the fuel lines further.

Hope I make sense!!

[prithm]

Originally Posted by a4anurag

But risk factor is too high. How will you know the quantity left other than assuming? In the process​ I followed, I could see the level and judge when to stop to avoid air lock issues. Also there is a risk of heating up the pump since the quantity in the tank will be lower than the pump height. Plus there are chances of dirt being sucked from base of fuel tank due to low level which could possibly clogg the fuel lines further.

Hope I make sense!!

Makes perfect sense and I did not take into consideration the pump temperature.

I did injector cleaner at 10000 klick service at Gem. Mine is petrol DZire, they had the injector cleaner apparatus (milk can with multiple pipes at the bottom) and took me 10 minutes and Rs.700.

One more thing, the Boost Sensor cleaning part. How easy is it to access it and clean it with IPA ??

[a4anurag]

Originally Posted by prithm

Makes perfect sense and I did not take into consideration the pump temperature.

Originally Posted by prithm

I did injector cleaner at 10000 klick service at Gem. Mine is petrol DZire, they had the injector cleaner apparatus (milk can with multiple pipes at the bottom) and took me 10 minutes and Rs.700.

Observed any change though 10K kms is nothing much to clog the injectors, but still.

Originally Posted by prithm

One more thing, the Boost Sensor cleaning part. How easy is it to access it and clean it with IPA ??

Slightly difficult to get hold of the nut which is at an awkward angle plus lack of space makes things even more difficult, somehow managed to get it out, clean it and re-fix.

Since you have a petrol the sensor isn't present IIRC. It is only in diesel cars.