Hi, I'm trying to locate a front oxygen sensor for a 1.8GDI 2000/01 pajero IO, Chasis:H76W, Engine:4G93. My vehicle is rough idling: revs falling to almost zero and then rising up to about 800rpm causing the engine to tremble and the mechanic thinks the prob is a faulty O2 sensor. Other probs include hard starting and a violent surge when i put the vehicle in drive. U can email me at asap13@hotmail.com

Thanks for any help, i'm getting desperate lol

maybe try the pajero section. this is the eclipse section

you may want to take you car to the shop cuz if you cant locate the right section of this forum then you have no chance of finding the front o2 sensor

Wrong place.
Thank you for playing, try again.
Moved.

Doubt if it is an O2 sensor fault. If this sensor fails the system goes into open loop mode and you run a bit rich.

I would think it either has a throttle AFM fault or another common problem is intermittant electrical connects from the ECU to all the engine sensors. Try removing each electrical coupler and cleaning with some emery cloth and contact cleaner. You may find that this simple tip solves all sorts of funny problems.

One other comment I'd like to make is downloading the diagnostic fault codes from the ECU. If your mechanic has not done this and is only guesiing at what he thinks is wrong I'd look for another mechanic. I'm not really a fan or people who like to parts swap at your expense.

Jim

Agree with Benckj, this problem seems to be more about Throttle AFM.. i would strongly suggest a maintenance to the throttle body, this is a replacement guide http://www.mitsubishi-forums.com/t41942-sh...ement-guide.htm but it would give you the basic reference about this part.

Luisfer.

hey thanks for the help, the link was interesting will give it a try this weekend and let u know how it goes

hi, i had the trottle body serviced and the connections cleaned but im still idling erratically. My hydraulic lifters/adjusters are really noisy and my new mechanic thinks that they could be causing the problem. Based on what i read in the manual i personally thought it was the air flow sensor or the trottle body but both these were checked and cleared. Just wanted ur opinion on this new diagnostic, do u think the adjusters could cause erratic idling?

Thanks in advance

Rommel

Was there any code that yu got? As in engine performance , system lean bank 1 sensor 1 or anything like that. There are lots of things that can cause that issue and not directly be the HO2Sensor. As in the model yu have is an HO2S , not an O2S . HO2S do not dramatically fail as fast as the older non heated O2Sensors. Depending the engine series , 4G93 had a version with auto hydraulic valve lifters while many other models did not. The majority were manually adjustable. On the GDI engine a few things can cause an erratic idle , which will not as much make that big a differance on regular petrol models. A vacuum leak is one. This will cause unequal air to fuel ratio and higher than normal air volumes into certain cylinders. Thus burning to lean in certain cylinders and making the idle , rough and uneven , erratic , and also would set a engine performance code , such as system lean bank one , or the frunt HO2S.

Also an extremely clogged fuel filter. Spark Plugs. One main thing that can also , which would ve very noticable on teh GDI engine , is if an model with hydraulic valve lifters , and a few of them have failed , it would cause unequal volumes of air to enter the cylinders , thus an erratic idle etc. Or if the manual adjustment is disrupted , or needs to be readjusted or set , or if the lock nut for the adjustment has backed off , , this would also cause as with the hydraulic lifters , noisy valvetrain operation and also an erratic idle.

Having noisey lifters generally will not cause eratic idle problems unless they are really bad. If this was the case you would have many problems at all RPM's especially when under load.

Another common problem is with the fuel supply. Many owners have found partially clogged filters in the pump and engine. I'd check and replace these plus measure your fuel pressure from the pump as there have been several reported cases of air getting into system fro leaking O rings or lines.

It is also a good idea to really look over the engine for vacuum leakes as this can show as poor idle. Old trick is to use a butane lighter and release the gas (don't ignite) and slowly circulate around your engine bay by any vacuum lines. If the idle suddenly increases you have found the leak!

jim

Hi Guys,

How often would you have to change or replace your ignition coils or spark plugs on a 1.8GDI 1999 pajero IO, Engine:4G93.

regards

Val

it's most depend on wich type of spark plug are you using.. ? iridium sparks are most Hard and last long, however also are the most expensive.

And the ignition coils should be repaced every?