The Mitsubishi Pajero Owners Club®

offroadflow · Posted: Thu Jul 02, 2015 13:54 Post subject: no power/knocking sound/EGR

Man, man, man....
I read through too many EGR-posts to be sure what i should do next.

To explain my situation in a nutshell:
When accelerating in lower revs, knocking sound appears, no power.
After taking the foot off the pedal and on again it runs fine again.
Only does this when warm...
So i cleaned the EGR valve and it moves steadily back and forth (depending on the situation) - guess this is OK.

What i noticed (keeping the left index finger on the moving part of the valve and the right on the pump to play with the engine) is that every time i accelerate from idle, the valve closes instantly for a second or so. And if it does not, the knocking sound appears.
So there is a connection, but i guess it´s not the valve itself, but something with the vacuum system..?

Any thoughts on that please..?
lonely

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offroadflow · Posted: Fri Jul 03, 2015 11:10 Post subject:

UPDATE:

Undid the vacuum hose from the valve and closed the hose off with a screw, so the valve keeps closed.
No more knocking sound and much quicker response of the engine.
Seems solved this way, tho one question remains:

What is causing the malfunction of the valve?
It´s not the valve, but the vacuum circuit or the control of the circuit.

I played with the engine yesterday a bit.
When i unplugged the potentiometer on top of the pump housing (throttle control?) the valve stopped working as well.
Maybe the poti is on the way to be worn out..?

peteinchad · Posted: Fri Jul 03, 2015 16:17 Post subject:

What model and year is your truck?

offroadflow · Posted: Fri Jul 03, 2015 16:28 Post subject:

Montero 2.8 GLS, year 98...

peteinchad · Posted: Fri Jul 03, 2015 17:32 Post subject:

I'm afraid I only know about the trucks up to 1996 - they changed quite a bit in 1997.

All I can suggest is to check all the vacuum pipes for leaks.

offroadflow · Posted: Fri Jul 03, 2015 18:14 Post subject:

Illogical to do so since the vacuum does not go away quick enough in case of closing the valve...

Simon_W · ******* Joined: 21 May 2013 Posts: 4881 Location: Watford

Like Pete, I've also got an earlier version of the 2.8 with a fully mechanical pump, so I don't know the later version at all. All I can tell you is that I disabled the EGR on my 2.8. Maybe more relevantly I also disabled the EGR (via some electronic trickery) on my then very badly running Mercedes 3.2 diesel. When I did it, I'd already spent quite a lot of money on having the injectors refurbished - which turned out to be pointless. Disabling the EGR transformed the vehicle. So if blocking off the vacuum hose to the EGR valve has solved the problem, can't you just leave it that way?

offroadflow · Posted: Fri Jul 03, 2015 20:07 Post subject:

Indeed I can and will for now, tho still curious what ACTUALLY causes this problem.
I guess many others would be pleased too since this is a common problem...

Simon_W · ******* Joined: 21 May 2013 Posts: 4881 Location: Watford

My own experience is that EGRs are fine when an engine is brand new, but increasingly less good as an engine ages. As someone said to me "an EGR is making an engine consume its own excrement".

I guess to find out why yours is misbehaving you'd need to know exactly how the EGR is mapped and then compare the actual behaviour to the intended. Presumably there's an ECU that controls it?

offroadflow · Posted: Fri Jul 03, 2015 21:59 Post subject:

good question, but possible cause i saw a service socket besides the fuse box inside.
the injection system is fully mechanical tho...
tried to find plans, but only got for versions 2001 and 2002, so not correct for my one...

offroadflow · Posted: Tue Jul 07, 2015 19:31 Post subject:

Anybody can provide more info or even a plan for this please..? read2

offroadflow · Posted: Fri Jul 17, 2015 11:34 Post subject:

unplugged the vacuum hose from the valve and blocked the hose with a screw.
ever since it runs great!
such a *beep* thing this EGR-"solution"....... Rolling Eyes