98 windstar - p1538 intake manifold runner control

Glad to have found this site, Cartracker still seems to be down. Anyways if anybody can help me....have 98 windstar, p1538 code, IMRC.
I have physically checked both IMRC's and they are functioning as they should. (if they were bad, they would not move at all right?) Assuming they are good, does anybody know which step in the troubleshooting process I go to now? The van runs perfect, just that darn light! LOL Do I start going for the O2 sensor now? Can anybody tell me what to next in the chain of troubleshooting? Thanks in advance!

I have a '96 3.8L....so that is my point of reference...

On the passenger side of the engine....you will be able to see the 2 IMRC actuators.

Follow the linkage to the end of the shaft that passes through into the lower intake manifold......On the end....you will be able to see 2 stops.....1 for fully open.....and 1 for fully closed.

With the engine OFF....verify that the IMRC is against the fully OPEN stop for BOTH the front and back shafts.

Start the engine....verify that the IMRC is against the fully CLOSED stop for BOTH the front and back shafts.

If one of these conditions is not correct......you will need to correct it....maybe dirt in the way.....or some other easy & cheap solution.....a little dirt built up on the stop.....or in the linkage can cause the problem.

I have read posts about the plastic bushings breaking / binding....can be bought and replaced.

If they are both correct.....verify that the connections to the sensor / acutators are good (unplug and plug again)

Mine are vacuum actuated.....and electrically sensed. If you have a code reader....you can clear the codes.....and try checking the sensors.....unplugging 1 and seeing if you get a different code....etc.
Is this a solid failure?.....as in...clearing the code....does it come right back?

Hey Thank You for that advise Wiswind. (The name just hit me..are you from Wisconsin? Neenah, Wi here!) Anyways, I will be checking those tomorrow- ie. the linkage on the other ends. Yes mine is also vacume actuated and electrically sensed too. Yes this is a solid failure as well, I have cleared the codes twice now and within 2-4 days they return. I think it strange now a days how the vehicle can be running perfectly yet but the light is on etc. Once again thank you, and I hope to get more input from you if you can think of any. I will post back here after this weekend and let you know what I found. Have a good weekend.
Chad

Unbeleivable!!!! Thanks for the advise WisWind, as I was looking for the things you mentioned, I heard a hissing...there was a main vacume line disconnected on the backside of the engine! So far so good, autozone cleared the code and it is not back as of yet! thanks all

Great!......
That is the fix I like.....Cheap & Easy (once you find it).

Greenfield (south of Milwaukee here).

There are a few vacuum lines on the back of my '96 Upper intake manifold.....lots of oppertunity of something coming loose.

I have over 140K miles on mine....
I am very happy with how it is running.

One thing about the IMRC- Ford really put some thought into designing those things. My '96 had a leak at one of the o-rings where the shaft exits the manifold to the actuator. You have to replace the whole manifold because you can't replace just the o-ring. Nice. That had to be done twice.

Road rascal, I agree with you and more so... The whole IMRC thing makes me boil. All the cost of parts, machining, controls ... plus all the troubles ...and fuel costs for dragging the additional weight around.

For some device that activates at 3000 rpm!! What's that ... 95mph in top gear? I think I could have done without it.

Hey Guys, I just went through the whole thing. First of all thanks for the info. This got me started on the right track. I talked to a Ford mechanic while he was on his lunch break and he gave me some great advice.

To find out which one is leaking pull the vacuum line from one of the controllers and plug the end with your finger. The other one should move. The one that does not move is the leaky controller. Be prepared to pay a heafty price to replace though. Ford is proud of this little unit at over $200. The mechanic said 90% of the time the one closest to the radiator is the one that leaks.

Also if this condition has existed for a while you may also get a P304, and P402 error codes which is a miss fire in cylnder four and excess EGR flow. This most likely is caused by the problem with the runner control. What happens is carbon builds up in the other two EGR ports on that side. If this happens he told me to pull the upper intake manifold, and underneigth you'll find the EGR ports. Clean them out and reinstall the manifold. This took me about an hour and a half to complete. The most troublesome part was removing all the vacuum lines on the back side.

Hope this helps and Good luck!

Piggybacking on this, if you don't have the bushings in there, the IMRC can easily stick closed, so you don't get the extra air in the above-2 or 3K power band and your gas mileage sucks.

Downside-- you pretty much have to pull the upper intake plenum in order to get the little rascals in.

Thank you all so much, you have saved my butt...
the IMRC has went out on my windstar i bought 3 days ago. until 15 minutes ago i had no idea what an IMRC was.
I called FORD and they want $249 for the part and $60 an hour to check and replace it... Now that I know what it is I'll replace it, and save a little cash

Just looked at my IMRC 's .
BOTH rods were completely off the manifold just lying there. Ordered the new bushings from " ROCKAUTO.com" for 2.90 each.

I started getting 1537 and 1538 DTC's about 3 months ago which is the code for "Intake Manifold Runner Control Stuck Open". About the same time I noticed that my A/C and vent would only blow out the defroster.
Any chance that both are related to a vacuum leak?

Thanks

I started getting 1537 and 1538 DTC's about 3 months ago which is the code for "Intake Manifold Runner Control Stuck Open". About the same time I noticed that my A/C and vent would only blow out the defroster.
Any chance that both are related to a vacuum leak?

Thanks

Sounds like a very good place to start. What year and engine do you have? The IMRC actuators change from vacuum driven to electronic between 98 and 99 I believe. Another thing to check is the bushings where the actuators attach to the IMRC shafts. Often times these wear out and fall off leaving the IMRC butterflies open.

Mine is a 1997 Ford Windstar with the 3.8 V6. Its pretty hard to actually see them. I can see the front rod and bushing or grommet and it looks intact. The replacement part pictures online appear to have a vacuum line attachment so I'd guess you are correct about them being vacuum driven.

Would I be correct in assuming that if the engine vacuum tests OK they are either defective or the actual runner controls are gummed up?

Would I be correct in assuming that if the engine vacuum tests OK they are either defective or the actual runner controls are gummed up?

I think it's pretty safe to assume that. One way you can check is to have somebody else start the car while you watch to see if the IMRC actuators pull the rods into themselves. You can also check to see if they aren't holding vacuum by removing the vacuum tubes, manually closing the runners (pull the rods into the actuator housing), and place your thumb or another finger onto the vacuum port. If, when you let go of the rods, they spring back to the open position, you have a defective actuator that no longer holds vacuum. The actuators shouldn't be difficult to access, however the IMRC vacuum solenoid is best reached with the cowl removed and could be your issue since both stopped working at the same time. The runners should actually move manually with little resistance other than the attached spring. If you can't seem to move them easily while the car is off then you may have some gummed up runners and you would have to take off the upper intake manifold to verify the issue. It is really pretty simple, but I would recommend removing the cowl to accomplish the task as well as picking up a Haynes manual or at least registering at Autozone.com so that you can access their FREE repair guides.

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.

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

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!!!

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..