Pajero Owners Club of South Africa

The 3.2 4m41 non-common rail engine has an idle butterfly that uses a vacuum diaphragm to close the throttle butterfly about 95% in order to reduce noise and vibration at idle.

This mechanism only kicks in when the engine is at operating temperature, and ill adjustment can create stalling and/or driving/starting issues at idle when warm.

Blocking the vacuum pipe that feeds that diaphragm will throw a CEL.

[BBvideo 425,350]http://www.youtube.com/watch?v=fR4NC2vVH8U[/BBvideo]

When we block the EGR valve is not necessary to adjust the idle butterfly to let in more air at idle in warm? Thereby compensating for the absence of EGR gases?

Off topic: do you know if the engine 4m41 has or not an oil temperature sensor?

Best regards

Rui_DID wrote:When we block the EGR valve is not necessary to adjust the idle butterfly to let in more air at idle in warm? Thereby compensating for the absence of EGR gases?

possibly, but unless you have idle issues I wouldn't fiddle with it.

Rui_DID wrote: Off topic: do you know if the engine 4m41 has or not an oil temperature sensor?

I don't think so.

Hi Marius

I think this is the problem that I had December. ?the engine would die once I came to a stop street, ie braking to stop. I took it to a guy in Hartenbosch who fixed the problem. He said the mecahnism (solenoids) where dirty. the idling problem did stop. However, something else then whent wrong. I thought air may have gotten into the system so I bleed the fuel filter for air, and then thought to do it for water as well. Turns out I then found another problem.

After fixing the idling problem, the Pajero sometimes had dificulty starting, it choked and puffed and made a LOT of smoke. After a few tries it started normally again. This happened intermitently. back to what I found though, the service centre had fitted a faulty fuel filter. The tread to fasten the fuel sensor was cut double. So it messed up the thread on the plastic fuel filter and it was not sealed properly and actually quite loose. I could not tighten it as the sensor was stripped. so when back and got a new filter and sensor.

Problem is, the pajero is still not starting properly at times. Blowing loads of smoke and then after some revving and restarting it starts normally again. I am also under the impression that there is some power missing, but not too much.

Any thoughts on what may have gone wrong in all of this. Should I have the idling thing replaced or will the fix be fine. The guy said the solenoids were full of dirt???

What may be the causes of smoking and choking?

I had it at Mitspro and he checked the computer. Error code said throttel controll was faulty. He cleared it and said to come back if the engine light comes on again. It has not but the starting problem persist intermitently.

I am going back to him but as this only happens every now and then and goes away after driving it is difficult to locate the problem. Would appreciate any inputs.

Thanks!!!

C

the test to see if it is the throttle butterfly system is simple.

Just disconnect the two vacuum hoses going to the throttle body and plug them with golf tees.

Go for a drive. The CEL may come on but won't affect power and will clear itself when you connect the vacuum pipes back and restart.

If the car behaves fine with the vacuum pipes disconnected then there's your problem.

If it still does funny things then that's not your issue.

Thanks will give it a try...

Hi Marius

Looks like you had it right. I disconnected one of the pipes and the problem seems to be gone. Now to replace the part

Thanks!!!

thekNack wrote:Hi Marius

Looks like you had it right. I disconnected one of the pipes and the problem seems to be gone. Now to replace the part

Thanks!!!

Good news. If I hear of a dealer wanting to change injectors or diesel pumps before checking the basics I'm going to blow a gasket!

Just remember that we have isolated the problem. The cause can be ecu, vacuum pipe leak, diaphragm faulty, vacuum solenoid faulty, wiring issue etc.

I think I have figured it out, maybe you can comment on my reasoning.

I had an idling problem december, and a guy in Hartenbosh said it was the solenoid unit that operate the vacuum seals that was full of dust. I called him on the new problem, and he said that the solenoid unit had a few disconected pipes and a few that were connectoed to the wrong places. So he cleaned the whole lot and receonnected everything to the correct places. It was basically then that the new problem started.

So I am thinking that somewhere somebody disconnected the throttel butterfly, but did not plug the pipe. So the system sucked in dust into the solenoid unit, which in turn jammed the solenoids. So when this guy reconnected everything, he unknowingly brought back an old problem....? So a quick fix by previous owner/workshop caused this.

does that sound possible? Anyways, at least I know where to look now.

Pajero is on 195 000ks and running like a dream know that she is not choking herself (-:

You can do all this and still have to repair the pump. If it stalls at junctions and has no power below 2,000rpm and is a manual, also is lumpy to start and sounds like it is jumping off the mounts. Most likely is failure of the pump rotor head.