My recently purchased Pajero 3000 Efi, V6 doesn't rev to over 3500 Rpm in neutral, app 2700 when driving/in gear. Upon reaching app 3500 it cuts out until revs are back to 3000, then increases again etc. The effect is similar to quickly moving the accelerator pedal up and down. If the plug to the airfilter housing (mass airflow sensor I assume) is taken out, it does rev normally, however it obviously misfires and smokes a lot. A mechanic has looked at it and has discovered that there is also no response to the throttle sensor. Does anybody have an idea of what the problem may be and how it can be solved? I live in the North of mozambique (Pemba) where there are almost no spares or proper mechanics.
Hi Pemba. Welcome to the forum.
I saw your post on other forum but couldn't answer.
My bet is on one of 2 things.
either your advance isn't working
or your fuel filter is clogged
To test the advance is simple, just hook up a timing light and look for the degree markings on the black plastic cambelt cover - the timing notch is on the front crank pulley closest to the engine.
If the advance stays stationary then make sure this brown connector is not grounded.
- the black connector can be connected to 12v to let the fuel pump run.

if that fails then replace the fuel filter. It is located underneath the vehicle on the ladder frame chassis. Be carefull as the filters are made of aluminium and the threads strip easily. Use new copper washers.
Let us know what you find.
I saw your post on other forum but couldn't answer.
My bet is on one of 2 things.
either your advance isn't working
or your fuel filter is clogged
To test the advance is simple, just hook up a timing light and look for the degree markings on the black plastic cambelt cover - the timing notch is on the front crank pulley closest to the engine.
If the advance stays stationary then make sure this brown connector is not grounded.
- the black connector can be connected to 12v to let the fuel pump run.

if that fails then replace the fuel filter. It is located underneath the vehicle on the ladder frame chassis. Be carefull as the filters are made of aluminium and the threads strip easily. Use new copper washers.
Let us know what you find.
For a small fee I will bring you the parts and a decent mechanicPemba wrote:I live in the North of mozambique (Pemba) where there are almost no spares or proper mechanics.

Welcome to the forum, hope you get it sorted out soon!
Thank you very much for your reply. We have had no internet here for a few days so I couldn't reply earlier. In fact the fuel filter was very dirty, maybe almost blocked. We substituted it but no difference. Then we opened the tank and had a look at the (filter on) the fuel pump. This was fine. I agree that there are indications that the problem may be related to fuel supply, the obvious one being that it revs up to 3500 RPM in neutral and around 2700 RPM while in gear/driving. However, these 2700 RPM are reached irrespective of fuel demand, going uphill or downhill makes no difference. Also, if you unplug the airflow sensor, it seems to run sort of OK (although smoking and misfiring a bit), however it uses a lot of fuel (1 litre every 3 km or so). I don’t have a timing light, but I am wondering what controls the timing? Somebody else in another forum said it must be a faulty airflow sensor which has confused the ECU which now needs error codes reset. The mechanic here and I are starting to agree that this may be the case. I am wondering do you have any idea how I would get the error codes reset ? Do you think I could unplug the ECU and send it to South Africa to get that done ?
I would check the timing first. If you eliminated the fuel filter then the only other option would be the timing.
the ecu might be to blame but not the MAF.
The ecu takes readings from the MAF and adjusts the fuel mix but even with the MAF unplugged it should redline - been there done that.
Get the timing checked out.
You can read error codes from the MUT but I doubt those ecu/engines have a limp mode.
Other than that you may have a blocked exhaust but I doubt it.
Try the timing checks I lined out above and try this link to check for error codes
http://www.4x4wire.com/mitsubishi/tech/ ... eshooting/
the ecu might be to blame but not the MAF.
The ecu takes readings from the MAF and adjusts the fuel mix but even with the MAF unplugged it should redline - been there done that.
Get the timing checked out.
You can read error codes from the MUT but I doubt those ecu/engines have a limp mode.
Other than that you may have a blocked exhaust but I doubt it.
Try the timing checks I lined out above and try this link to check for error codes
http://www.4x4wire.com/mitsubishi/tech/ ... eshooting/
This is great stuff! I have actually also now discovered that there is somebody here with the thing that reads the computer
(I wouldn't be surprised at all if he was the only one in Mozambique), and I have an appointment there this morning but with that article I am confident that i will get a lot further if I need to this time, but also in the future. It is seriously helpful. Thanks very much. I will let you know what happens.
(I wouldn't be surprised at all if he was the only one in Mozambique), and I have an appointment there this morning but with that article I am confident that i will get a lot further if I need to this time, but also in the future. It is seriously helpful. Thanks very much. I will let you know what happens.