[Chris2]

Before i start, let me just inform you that I have almost no technical knowledge of my Paj's engine, let alone the diesel pump. So, not sure how to explain this, but I will try my best:

My 2006 SWB 3.2 DiD started showing the following 'symptoms':

• heavy on fuel (get approx 450 km on a tank...

• feels as if I am loosing power when accelerating when going up a hill

• when driving at steady speed say 130km/h and I want to overtake a car, the auto gearbox does not step down for long long enough so I can get enough power / speed to do so; the revs would go up to 3500 rpm or so and then it would immediately go back to just under 3000 rpm - this was not so when car was new(er).

I checked with Mitsubishi Motors in Durbanville where I had my car serviced previously and they informed me there is no specific maintenance task to be taken on my Paj. When I looked at a copy of the MMC Diesel Service Sheet for the 3.2 DID Auto (GLS and GLX), it indicates at point no 24 that on: 45000, 90000, 135000, 180000 km the following needs to be done:

[tab=30]"Injector nozzles" - this includes the nozzle spray pattern, opening pressures, tip condition, etc
So, this was never done by Mitsubishi - is that acceptable?

I now have the following questions:

1. [1]can these symptoms be pointing to an issue with the pump, injectors, etc?

• [2]if so, can this type of repair / service be done by non-mitsubishi agents?

• [3]I was informed by JJ at Mits Durbanville that only Alan Black is authorised to work on their pumps...??

• [4]can the injectors be tested by a good diesel technician?

• [5]can one replace the injectors and if so, what is the cost?

• [6]does anyone know of a good place in Cape Town where i can have this pump-issue looked at?

• [7]any other advice will be appreciated.

PS - I also dont know if my fears have any ground to it; maybe I am just too critical on what otherwise might have been considered "normal"?

Thanks for your assistance..

[4ePajero]

Sorry to hear about your problem(s).

1. Hit-and-miss solutions are not advisable.
2. The agents are usually only good at replacing parts (until eventually the problem is solved)
3. what you need is a proper diagnosis, to identify the problem.
   Take the vehicle to a good independent diesel specialist for a diagnosis (the CT members will point you in the correct direction)
4. yes, the injectors can be replaced. Mitsu are not the only suppliers. PM bold4E and ask him which injectors he used when he re-built his Di-D
5. Although there is no such thing as "only ones authorised ...", Alan Black is definitely very good at fixing Di-D pumps.
6. When last did you replace the fuel filter?

[4ePikanini]

if yours is the non common rail (take a picture from the battery into the engine bay so we can confirm) then, yes, you may need to have injectors checked out.

They are mechanical injectors with 2 springs in them creating 2 squirts (a small squirt before TDC and then roughly and TDC the main big squirt comes.)

Over time the springs may fatigue and cause the spray to come out too early at too low a pressure resulting in less misty spray. This lacks power, fuel consumption and can burn pistons due to large droplets hitting the piston at the same spot and burning there. There is no cure for this condition.

Also over time the injector may get varnished up by diesel (fact of diesel injectors and bad fuel in RSA) and cause reduced flow through the injector or incorrect seating of the tip, which cause bleeding and dripping of the injector. This also creates hot spots as no sufficient pressure has built up to fire the injector at high pressure for good mist spray. A few tanks treated with wynns diesel additive may cure the problem.

Another possibility is wear of the injector pump through years of bad diesel (latest diesel does not have the lubricity of older diesel sold a few years ago)and not producing sufficient pressure anymore. This is highly unlikely as I have NEVER heard of a failed 4m41 pump (except a few that failed early and got replaced under warranty but that is a scarcity on it's own as well)

Another possibility is that your injector tips are carboned up through years of use. The let the injectors spray funny patterns and you get partial combustion in localised spots of the combustion chamber. This can cause washing of the cylinder walls by the fuel causing excess diesel to get in the sump and accelerating wear on engine components. To cure this you may try to add about 250ml 2 stroke oil to your diesel for every tank full. It is a known fact that 2SO mixed with fuel at a rough ration of 200:1 creates a decarbonising burn in the combustion chamber and can remove (and prevent further) buildup of carbon deposits on injectors tips, pistons, exhaust valves and exhaust ports.

Another possibility is that your egr system is finally causing problems (egr recycles exhaust gasses back into the intake for euro emission reasons - reduces NOx gasses) and when the exhaust gasses combine with the oil vapours from crankcase venting system it creates carbon gunk in the intake system robbing power and economy. The cure for this is to remove the intake manifold and throttle body, clean them and put back (In addition, a good idea would be to block off the egr system for the future)


My advice

Take the intake pipe off at the throttle body (or the whole throttle body), take a picture and post it here for us to comment.
Drop 2 bottles of wynn's diesel additive with your next tankful and after that run 2 tanks diesel through with each having a 250ml 2SO bottle thrown in.
After your feedback we should be able to give a more accurate diagnosis.

Hope this helps. The fundis will chime in shortly where I errored.

[4ePajero]

Although i agree with what Marius sid, it assumes that the problem does lie with the injectors, which has not been confirmed!
(refer to my point #1 )

During the time it takes to use two or three tanks of fuel, serious damage can be done. (high EGTs etc)

Have the problem confirmed by a specialist. Then we can debate the solution.

[Chris2]

Sorry to hear about your problem(s).

1. Hit-and-miss solutions are not advisable.
2. The agents are usually only good at replacing parts (until eventually the problem is solved)
3. what you need is a proper diagnosis, to identify the problem.
   Take the vehicle to a good independent diesel specialist for a diagnosis (the CT members will point you in the correct direction)
4. yes, the injectors can be replaced. Mitsu are not the only suppliers. PM bold4E and ask him which injectors he used when he re-built his Di-D
5. Although there is no such thing as "only ones authorised ...", Alan Black is definitely very good at fixing Di-D pumps.
6. When last did you replace the fuel filter?

Tx Gerhard,
Just spoke to a guy from ANG Motors in Cape Town where I had the car serviced the last two times.
He confirmed they did not replace the fuel filters at any of the two services. Last service was at approx 140000 km.
I also discussed the issue with him (again), and we agreed to

• have the fuel filter replaced

• check some valve that could be bypassed, possibly also causing this type of problem

So, that is where I will start - thanks for the advice.

[Chris2]

if yours is the non common rail

Correct, mine is the non-common rail one (Jan 2006)

Over time the springs may fatigue and cause the spray to come out too early at too low a pressure resulting in less misty spray. This lacks power, fuel consumption and can burn pistons due to large droplets hitting the piston at the same spot and burning there. There is no cure for this condition.

Also over time the injector may get varnished up by diesel (fact of diesel injectors and bad fuel in RSA) and cause reduced flow through the injector or incorrect seating of the tip, which cause bleeding and dripping of the injector. This also creates hot spots as no sufficient pressure has built up to fire the injector at high pressure for good mist spray. A few tanks treated with wynns diesel additive may cure the problem.

Since there is "no cure for this (spring fatigue of injectors)", can one not just replace these mechanical injectors rather than using oil / engine additives? I assume its the cost that one would need to take into consideration, but is this not the 'better' option since then one has taken care of most of the things that could have gone wrong with the injectors? I will also consider blocking off the egr system as advised

Thanks for your assistance so far. Please dont stop providing more advice, etc..

[4ePikanini]

sorry. I didn't finish that properly.

Yes, there is no cure other than replacement. But i agree with 4ePajero to first identify the problem and then take it from there.

[CATS]

Last time I replaced injectorsbon the 4m40 it was R6000,or there abouts, and that was a couple of years ago. So make sure it is indeed the vause before you replace. The injectors can be checked by areputable diesel specialist.

CATS

[Gerrit Loubser]

Those injectors can be rebuilt, but few local diesel shops have the equipment to correctly test the dual stage injectors, so they won't touch them. Perhaps Allan Black is different, but that only helps if you are within reach of them or are able to park the car for as long as it takes to send the injectors up to them, for them to fix them and to send them back.

[Chris2]

Sorry to hear about your problem(s).... PM bold4E and ask him which injectors he used when he re-built his Di-D

Hi 4ePajero

I cant find member "bold4E"... is that his profile name?