Pajero Owners Club of South Africa

So it looks like my easter project paid off.

I decreased my fuel consumption by 13% (from 7.9km/l to 8.9km/l) for less than a hundred bucks.

Just a bit of history on my issue with the IO's fuel consumption.
Initially I wasnt impressed with the IO's fuel consumption and tried everything that people (from all four corners of the earth) recommended.
- Removed the bosch spark plugs and replaced them with NSK plugs
- Dynotune
- Serviced the injectors
- CO2 tuning ect

Everything helped (by +- 0.3km/l) and got it up to 8km/l on average. Then, all of a sudden, 7km/l.

After reading the post on cleaning a MAF and cleaning a throttle body in SA4x4, I decided to test my mechanic skills and do everything myself. I ordered a new throttle body gasket (R20 from Mitsubishi East Rand) and a can of Carb Cleaner and Lectro Clean (R70 Autozone).

Everything when quite painless. Removed a 2mm carbon build-up in the throttle body, used a old toothbrush to clean the rust off the MAF curcuit board refitted everything once done and whala. The car starts but now its idling at 2500rpm. My local bosch helped me set the idling speed by turning in a small screw (dont know whats its called) on the throttle body in (probably 5 turns). He then said that this is where they previously set the airflow in the CO2 test.

Now my predicament is this
- While the throttle body was off, I stuck my finger into the intake manifold and it feels as dirty as the throttle body was. How big of a job is it to strip the entire manifold and clean it? In other words - can a person with limited experience pull of a job like this or should I leave it to the pros?
- Bosch set the airflow and fuel mixture previously for an extremely dirty throttle body and now set the airflow for a "NEW" throttle body, but they never touched the fuel mixture valve ma-gafter. Therefore I'm thinking that the car is most likely running lean. Is it safe to run a car lean for a long period as I would prefer to postpone the CO2 until the entire intake is cleaned?

All in all I am pretty happy with the results, lets just hope that they last!

Jaco

Hi Jaco,

Ive been looking at the exact same thing, last week-end I started removing MAF sensor for cleaning, but couldn't really do a decent job of it...yet

JacoV wrote:...used a old toothbrush to clean the rust off the MAF circuit board refitted everything once done and whala.

This is where I couldn't continue, I removed the whole Maf Assembly, removed it from front filter, cleaned the inside (where the actual sensor sits) I also took off the top plate (under which the circuit-board sits) and quickly slammed on brakes, I had no inclination of pulling the circuit-board out for inspection, as I removed the 4 screws holding it down, but it seemed to be sitting 'vas', so was not sure if it actually could come out.

Jaco,
Please could you elaborate on the removal of the circuit-board for inspection / cleaning, as I don't what to get it wrong, and then have to cough up 4K for a new one.

Regarding the throttle body, I also saw that topic on S.A.4x4 with much delight, and hope, and is the next step for me as well, I already cleaned the opening as much as I could without removing it yet.

Glad to see you've done it, and that it doesn't just pertain to 'Grants old Jeep' definitely going to do that the next chance I get.

One question I do have for everyone: The pipe from the intake manifold/engine (I'm not much of a mechanic) that leads back to the air intake just before the throttle body, for releasing the 'escaped gasses' I seam to get a lot of oil/dirt build up where that pipe enters the air intake (obviously from the oil from the engine) - what I would like to know is if I could lengthen that pipe, and possibly even increase its diameter to stop the oil build up within that pipe from pushing through to the air intake and fouling it and the throttle body.

That oily residue that you see is mainly condensate where the gas that escaped past the rings hit against the cold intake, there is a bit of oil in the mixture but it is far better for the engine to burn this lot rather than have the corrosive mix find its way back to the oil and contaminate that lot.

On my turbo golf I have a condensation tank to capture this gunk as I don't have positive crankcase ventilation, in other words it does not go back to the intake as I have that under pressure, the stuff I drain from this tank is a yucky gunk that I do not want back in the engine

Cleaning the throttle body and inlet is a good move as I suspect that most of the dirt probably accumulates there. My concern is getting the deeper part of the inlet manifold cleaned properly. On my Colt I found that there is still some dirt deeper in which is not easily accessible. Carb cleaner doesn't get all the dirt packed there over time off .

Quicksilver make a product called "Power Tune" it is specifically made to remove deposits from a two stroke outboard motor and is absolutely magic. It is one of the best carb cleaners I have ever used as it is not corrosive but will make a carb jet that has been lying outside in the rain and wet look like a brand new item in a jiffy. You can spray this down the throat of an engine and leave it to do its thing and then start without any fear of damage.

Mcnoogle wrote: This is where I couldn't continue, I removed the whole Maf Assembly, removed it from front filter, cleaned the inside (where the actual sensor sits) I also took off the top plate (under which the circuit-board sits) and quickly slammed on brakes, I had no inclination of pulling the circuit-board out for inspection, as I removed the 4 screws holding it down, but it seemed to be sitting 'vas', so was not sure if it actually could come out.

Jaco,
Please could you elaborate on the removal of the circuit-board for inspection / cleaning, as I don't what to get it wrong, and then have to cough up 4K for a new one.

Could anyone help with this.

Hi Mcnoogle

Sorry for the late reply. Pajero was in for new coils and decided to wait until I could take some pictures (and also had a battle logging on)

Anyway,

The circuit board cant be removed from the plastic housing as it looks like the actual sensor was soldered in (Green Arrow) after everything was assembled and bolted (Red Arrow). Use a lot of Lectro clean or similar (You can submerse it) and let it do its magic. Use an old toothbrush and remove rust off the top of the circuit board.
Hope this helps.

Jaco

Thanks Jaco,

What did you use to reseal the cover.

I must say, I didnt spot any rust, the c/b looks reasonably clean, but I'll give it the old once-over with electroclean & toothbrush.

Thanks for the clarification.

Well no visible rust is a good sign that its still in a good condition. Just remember to be careful on assembly as the honeycomb mesh and casing is sensitive.

Just use a little clear silicon sealant.

Jaco

Thanks guys.