Can anyone please point me in the right direction with my neighbor's car? It studders and jumps when idleing and seems like it is only running on four or five cylinders. It runs rough until it gets around 3k rpm. They have tried to fix it but nothing has worked but everything helps a little. But nothing solves the problem.The car ran fine and all at once it just started running bad.
Car info:
1992 Montero rs V6 4WD.
timeing chain replaced about 1500 miles ago all maintenance up to date

Parts replace trying to solve current problem
Plugs, plug wires, dist. cap, rotor, coil, ox. sensor, and fuel filter. also cleaned t/b. chainged oil and filter just to be safe.
the plugs on the driver side the front 2 looked black and sooty
all three on the pass side look sooty and can smell gas bad
Can anyone give me a direction to look now? They have threw a bit of money at the car and it has not cured it. I dont want to spend any more of their money than I have to to fix the problem.
Thanks to all in advanced
Shannon


also will someone please tell me the procedure for checking the mas?

 

is the check engine light on?? if it is find out what codes. that could tell u right there. if not, that year of montero had P.C.M issues. sounds like it is over fueling. most of the time if a pcm goes bad it just shuts off and thats it. the only way u can find out if it is the pcm is to have a scan tool to look at the data. if the pcm is bad, all of the sensors will read either way high or way low of factory specs. the only other thing i can think of is a bad coolant temp sensor. if the sensor is bad, it could be stuck at a very low temp reading and telling the pcm to dump fuel so the engine can get to operating temperature. good luck, keep us posted. greg....

 

obviously you need to diagnose it first.

if you're not capable of doing that, you will need to take it to a pro.
check for spark, fuel pressure, compression and proper timing.

 

OK here is where we stand today, before I could change or even check the CTS they took the car out and it died. Scott the driver and neighbor said that it backfired and died, and would not restart. I have not had a chance to haul it in so I am not sure what it did.
And as far as being able to diagnose it would have to show a trouble code or a check engine light would be welcome at this point. At least that would mean that the ECU would know that there is a problem. And it has been taken to "a pro" at two different local shops, they are unable to diagnose the problem other that to say there is some kind or fuel delivery problem, or they could not find what exactly the cause but they “think” it is a sensor malfunction.
The timing is good, and it has good fire at the coil and plugs. I have yet to have a chance to check compression and fuel pressure. I got involved with the problem after the had changed parts and ran out of ideas. I do have the equipment and knowledge, but I may not have the physical ability, as I am recovering from having back surgery in December. That is another reason I am looking for ideas. It makes it a lot easier to see if anyone else has had this problem.
Is there somewhere online that I can get the parameters of the air sensor, CTS, Ing. Module, and all other sensors, and what the fuel pressure and the idle control module? If I have to I will get a Hanes manual I would rather have a Chilton’s but there is no one that carries one here.
Again thank you
Shannon

 

there is a website that u have to subscribe to, but it is the best. we use it in our shop for all of our non mitsubishi vehicles. but it does have mitsubishi info. its straight out of our service manuals. www.alldata.com.