IMRC check

My 2000 Windstar 3.8 IMRC stayed closed all the time even the RPM is over 3000.
The 2 metal rods still connected to the right places. I checked the 4 wires to the connector and control voltages are +12v, +5v, ground, and the last one is high resistance (connection back to the computer?) Can anybody tell me how to test the IMRC?
When the key is off, what position is the IMRC (open?)
When the key is on, what position the IMRC (close-touching the metal stop?)
Thanks in advance!!

Milton.

All the questions you ask ... I forget the answers.

Except one ... How to test? I like to but a gob of heavy grease on the stop for the actuator.... go out and take a brisk ride ... lift the hood and see if the gob has been disturbed.

Thanks!!!
Is the IMRC open (away from the stop) when the key is off. Mine is always closed. This info will help me trace the control signal from the computer. I might have a broken wire going back to the computer.

Milton.

the check engine light will definatley come on if they are stuck either open or closed my 2000 lost the plastic clip that holds the rods in place and they were stuck open and it turned the CEL on.

CODES ARE: P1518 for open not sure about stuck closed but i tracked it down with a code reader and the internet....:)

The CEL did not come on when the IMRC stuck closed but OBD II did pick up the P code. I would like to know when the van is off, is the IMRC open???


Milton.

Hi,

Can anybody confirm to me when the engine is off, is the IMRC (electric controlled) open? :shakehead :banghead:
Thanks in advance.


-Milton.

I just did the lower intake gasket replace and had it out of the engine. When the linkages are disconnected, the IMRC butterflies are CLOSED. Unfortunately, I cannot tell you if they are OPEN with the linkages connected, I do not remember. If you unhook the linkages they will spring back to the CLOSED position if they are not there already. Unfortunately, you will have to break off the white plastic bushings that are there. The good thing is that you can get DORMAN replacements at Advanced Auto for about $3 for all 4. If you have never replaced them, you should. You can also get the Ford part for these, which are $8 EACH, but they are much better made (better than the originals, which are weak), more heavy duty and possibly made of teflon instead of nylon.

http://www.automotiveforums.com/vbulletin/showthread.php?t=293879

This should answer your question.

Hi,

Can anybody confirm to me when the engine is off, is the IMRC (electric controlled) open? :shakehead :banghead:
Thanks in advance.


-Milton.

The IMRC will be closed at engine RPM under 3000 for drive-ability and when you go over 3000 RPM they will open and they are controlled electronically i hope this helps.

Engine OFF-3000RPM = CLOSED
Engine 3000+ RPM = OPEN

Thanks you guys,

The vacuum operated IMRC is open when the engine is off. I would like to know if the electronic operated IMRC is open or close when the engine is off?
By the way my IMRC was replaced with a new one and the butterfly valves were moving freely when not hooked up to the IMRC.

-Milton.

i have the page extracted from my repair manual but it won't let me post it i will try again in a little while

The whole effort is for better mixing of fuel and air. The injectors have to fire at the beginning of the intake ... so the fuel goes fully in the cylinder ... and the designers want the injection to occur when the air velocity is very high. That's why the intake is "narrowed" at low rpms/low-intake. By "narrowing" the intake passageway (closing the butterfly) at low rpm, the air velocity is kept high as it goes by the injector. At high rpms, the velocity is high even as the butterfly is opened to increase total air intake.

In newer engines with direct injection, this whole issue goes away .. as the injection timing can be somewhat independent of the intake air velocity and timing.