98 windstar - p1538 intake manifold runner control

[wiswind]

The way that the 1996 through 1998 IMRC system works (1995 did not have the IMRC system at all....and 1999 and newer uses a electrical actuator for both banks) is that EACH bank has a vaccum driven actuator.
Each bank has a STRONG spring that holds the IMR OPEN.....
When you start the engine, vaccum in the intake is directed to each IMRC actuator and pulls each bank CLOSED.
The IMRC system is CLOSED most of the time.....in only opens when you are in a hard accelleration situation.....like passing on a 2 lane road.

The normal failure is for one of the actuators to develop a leak in the diapham and this often is a big enough of a leak to rob the other actuator of the vaccum to drive it.
BOTH actuators share the SAME vaccum line from the IMRC vaccum control solenoid.
So....often only 1 actuator is defective....but causes BOTH to not work.
The actuators are quite expensive....so determination of which actuator is defective is a good move.
If you note the position of the IMRC shafts..........which will be OPEN with the engine not running......THEN....start the engine.....they shoudl both move to the CLOSED position.
If they are both STILL open....then pull the vaccum line from 1 of the actuators and put your finger over the vaccum line that you just removed.....does the othe actuator pull CLOSED?....if so....you just found the 1 defective actuator.
If not.....reconnect the vaccum line and repeat the process with the other actuator.
It is possible (if you have luck like I do) for both to go bad at the same time....but it is unlikely.
So....if the above check does not work.....Did you feel a vaccum at the vaccum line?.
If not.....look for a defective or disconnected vaccum line.
The solenoid is not noted as a high failure item.....but there will be a vaccum line from the REAR of the upper intake manifold to the IMRC vaccum control solenoid.....from there 1 vaccum line will branch out to both IMRC actuators.
The Solenoid has a electrical connection that connects it to the PCM (computer).
Do NOT race the engine to try to see if the IMRC opens at the correct value of RPM.
There are several conditions to be met to open them.
Again.....the IMRC system is OPEN when the engine is NOT running (no vaccu present to hold them closed). They are held open by springs.

A/C vent blowing ONLY out of the defroster is caused by a loss of vaccum to those controls.
The direction of air (not temperature of it) is driven by vaccum.....you guessed it....from a vaccum line that connects to the back side of the upper intake manifold.
There is a chamber that is mounted on the passenger side inner fender that holds a "reserve" vaccum to hold the diverter door(s) in the correct position that you have selected.
If you look up under your dashboard.....you will see the vaccum lines running to the several doors that direct the air
If there is NO vaccum....then all the air will go to the windshield.....defrost mode......so you can defrost/defog your windshield and see where you are going.
SO......in this case, you will need to locate the source of the loss of vaccum to the system.
A vaccum line passes through the fire-wall to the various diverter door actuators.

They shoudl CLOSE when you start the engine.
That is all the test you need to see if they are working correctly in 99% of the cases.

[weenerautoforum]

98 windstar 3.8 got bank 1 imrc stuck open, bank 2 imrc stuck closed (from Advance auto reading). Anyone know what this indicates?

[zaf1419]

Hello Everyone,
I know this thread is old, but I really need some help. We have replaced the IMRC Actuator #2 (O'Reilly or Napa has the best pricing) and bushings. Have cleaned out under the intake plenum and verified all vacuum lines. We are ready to replace the IMRC Solenoid on the back of the intake, but want to confirm which port is in (from the vacuum reservoir) and which one is out to the actuators.
Can someone please help!!!

[oldgearhead]

My 2001 Windstar has the electric IMRC actuator. While I was doing the TSB for the intake manifold bolt seals, I saw that the bank 01 (toward the windshield) rod and retainers weren't there. So I obtained the parts and installed them. What I wanted to say is it was
impossible for me to put the retainers on the rod and push them in the square holes, but it was much easier, at least for me, to put the retainers in the square holes and then push the rod end into them..