please help , PO401 code. EGR valve opens up completely with a hand pump, motor starts to run rough when I do that. next I check the suction from the manifold , it reads at 20inches of vacum, then I measured after the solinoid, and it still reads the same. Then I disconnect the electrical plug from solinoid, measure the vacum, still 20 inches. of course I measured at 2500rpm. anyway I removed the solinoid and checked the resistance on it , it was 31.7ohms. then I tried to blow through it and suck through it with mouth, - its open at all times, until I put 6volts to it, then it closes up. then I also tried 12volts, - it also closes up. as soon as I let the power off, it opens up. My question is - does this particular model have completely opposite way the solinoid valve works? I found that the EGR valve is open about half way at idle. I imagine some vacum is lost through the purge control valve, which tees off between the solinoid valve and the EGR valve , then goes back into the manifold. If I close the line leading to the controller, the EGR valve opens up all the way instead of just half.

 

when I accelerate the valve moves towards the closed position only while the engine is picking up the rpms(1/2 second). this only happens with everything connected like it should, but when I plug the line that tees off to the purge control valve nothing moves while accelerating

 

Hi inbilya, first of all - great detail in your post. Thanks for not posting - "P0401 code - what's wrong with my truck?"
It sounds like the EGR valve is operating at the wrong time. It should be completely closed at idle and open only at higher RPMs. According to your description, you get it working backwards. I believe your solenoid is operating as designed, but perhaps it is not connected correctly. If you look at the attached diagram, you'll notice that the vacuum at the EGR valve will only be created if solenoid is closed. I suspect that some of your vacuum lines may have been incorrectly connected. I'd recommend checking them against the diagram. Make sure correct lines are going to correct ports on the manifold (letters are stamped on manifold). This vacuum diagram is from older model year but it sounds like exactly the same design. Good luck.

 

Thanks for quick reply. It would be hard to misplace the lines as they are partially steel lines, mounted to the throttle body, and only some rubber tubing, it is kind of obvious where they need to go. They diagram looks completely different than what I have. If I look on the diagram , the purge control valve (not solenoid type) would be in the midle of the green line between the tee and the E port. Also wanted to ad, I found used solinoids with same part number on ebay and asked a couple of sellers to do a simple test for me - blow through it when not connected, they said that air goes through easily.

 

You'd be surprised how easy it is to connect a wrong rubber vacuum hose to wrong port on the manifold/throttle body. Here is a link to a couple of diagrams with the vacuum control valve (brown thing like you show in the photo). Perhaps one of them is closer to your setup.
2001 montero sport looking for egr solenoid vaccuum line - Fixya
BTW, did you check if the vacuum passages on the manifold are clear? It is possible that one of them is plugged and that throws the system out of balance and results in EGR valve opening at the wrong time.

 

I think I made a mistake I said "purge control valve" , but I think its called "vacuum control valve". seems like they are completely two different things.

I will describe my system " line comes off the port on a manifold, and goes to the solenoid valve, then splits in two lines , one of which goes to the egr valve, other through the vacuum control valve and back into the throttle body via a different port. I know the port we are starting with is not blocked, because I get vacuum from there, should the other port also have vacuum in it? how to clean it ?

 

I just purchased the cd manual from ebay, hopefully it will have more exact information for my year car

 

Both ports should be clear. My guess is that there is a difference in vacuum between two ports and the regulator valve controls how much is there in the end. You can spay carb cleaner in there to make sure all is clear

 

here is the diagram for my mitsu , I will be checking soon

 

Y and G hoses were placed on the opposite ports. seems like the problem is fixed. Just drove 30 miles at various speeds , no check engine light came on.