Intake Manifold Runner Control

After momentarily turning off the ignition, just long enough for the engine to start winding down, the check engine light came on and the engine started running roughly at idle and over 2K rpm. It will not run well at all over 50 mph.

The code set is 2004.

After looking on line for the Intake Manifold Runner Control, and watching a youtube video on fixing it, I checked the hoses for cracks and found none.

The price for a new Intake Manifold Runner Control is around $100. Should it be replaced or is there something else that could be done to fix the problem.

One thought is that the engine backfired out the intake and jammed the linkage open. However, no backfire sound was heard. Nevertheless, is there a way to check the linkage?

I would not only check the vac lines for cracks but also for blockages. I’d also be tempted to maybe pay for a smoke test just to verify the absence of leaks.

It would also be good to check the wiring to ensure that its getting & sending all of the right signal/voltage.

But if its not as simple as that, no matter what you do with the IMRC I’m pretty sure its just going to have to come off which is the hard part of the whole thing. So if you verify that it is a problem with the IMRC then pull it and see.

The only thing you might try before pulling it would be a SeaFoam intake treatment or two. If the butterlies are just gunked up with carbon or something it might help clean it out.

what I should really note though is that I’m sure there’s an actual procedure Ford specifies for diagnosing the actual problem. I don’t know what that is but I’d be tempted to find out first. (You’d need an actual Ford shop manual. You may be able to get access to this kind of info via the local library).

Thanks cigroller for the comments. The only place around here to look at a manual is the local shop. Darren might let me look at it if he is in. The library only has old Chilton’s.
The hoses are nice and pliable and firmly attached at both ends. Three ends anyway. The one between the head and firewall is hard to get to.
How does the smoke test work? Is it something like the propane test? 8-O
It is compelling that the light came on when the key was turned off and on. It was off for a second at the most.

This part is really hard to find…

A smoke test would be done by a shop by feeding smoke into the system to find leaks. Frankly, though - if you have a butane/propane torch to use and since you know the code is IMRC related you could just do that to be double sure about the absence of leaks.

I’m not sure I’m catching on to the whole connection with turning the car off - you sort of killed the ignition very briefly and cut it back on immediately? I’m just not sure why that should mess up the IMRC. Coincidence?

“. . . you sort of killed the ignition very briefly and cut it back on immediately?” Yes, you are exactly right.

If during the restart the engine turned backwards or there was a backfire, air flowing out of the intake manifold could have jammed the butterflies open. So, it would not damage the IMRC so much as prevent the operation of the butterfly. This is pure conjecture as I have never seen the equipment. The coincidence is too strong. I witnessed it happen, something caused the code to be set when the engine restarted.

Yes, your are right about the Ford procedure. The manual provides a series of tests to determine if the various parts of the system are working. It is comprehensive. However it assumes that the mechanic knows what parts are where and how to observe the operation. That will take some doing. Darren, the mechanic at CCCC, mentioned that they often replace a broken clip on the V6 engine. He has never had to fix a 4. His recommendation was to reset the code and see if it reappeared before doing anything else.

resetting the code and driving on is certainly a fine idea. But you also said it was running poorly. If its not running poorly anymore then by all means, clear it and drive on.

Either way I’d still be tempted to run some SeaFoam thru it to reduce & loosen up some of the carbon.

The linkage can be operated by hand. The vacuum servo pulls the valves open and spring tension closes the valves when vacuum is removed.It is likely that the engine backfired and jammed the butterflies into the bores. That would be evidenced if the linkage is immovable. If you carefully ‘coax’ the linkage, the valves may be freed but forcing will likely further damage the system.

After momentarily turning off the ignition, just long enough for the engine to start winding down

Why would you do that???

Not intentionally. :slight_smile: Small cabin - big elbows…not really, just changed my mind and did not wait to let the engine stop.

SeaFoam it is then.

Does some cover have to be removed to find the linkage? It is not readily visible. The IMRC is mounted on the side of the block. One hose extends to the back of the engine between it and the firewall, and the other hose goes up under the manifold cover. (Update: the hose connects to the manifold.) Where is the linkage found? Knowing this answer will also help when using the scanner to operate the IMRC. One of the tests includes entering something into the scanner which will operate the IMRC.

Here is the rest of the story:

After finding the control, (hidden under the intake manifold) identifying which hose went where, and buying an expensive hand powered vacuum pump, the actuator was tested.

It worked just fine. It could be heard moving freely when the vacuum was removed.

Plugging the hose back on the control resulted in the control falling apart.

Removing the control revealed that it was corroded and the plastic portion containing the hose connections had been forced out of its mounting and the glue/seal between the parts was broken.

(Did the backfire perhaps break the seal?)

After attempting to use some out-of-date five minute epoxy to glue the parts back together and finding the epoxy still soft 12 hours later, a visit to the Ford parts department established that the replacement was $140!

Conversation with the Ford parts manager follows:

Me, "Can you give me a better price?"
Him, -"how about 95?
“Wow, Thanks, that’s great. Do you have it in stock?”
-“no, but it is available today, call by 10 and it will be here at 11, or by three and it will be here at four”
“OK, I think it was $75 on the internet, I’ll call you if I want it.”

Well, whatever link I had found before was gone so I called back and went to get the part.

The counter man stuck his head out from the back and promptly exited.
Me,“What, am I that ugly?”
-laughter from the back
Parts man returns with the part and puts in on the counter by me and returns to the back out of sight…
Me, Waiting - waiting - waiting "Is it free?"
Him -"be right there"
Brings the sales-ticket "how is $80?"
Me, “Great, it feels like Christmas, thanks!”

The engine compartment is tight. After struggling with how to put the part in for some time, a 6’6" neighbor comes over and offers to help. He is able to reach from the front of the engine compartment to the mounting location and install the part in moments. (He knows nothing about cars and asks a bunch of questions about the part and what it does.)

Me, “it controls the size of the intake manifold so that the shock wave created by air bouncing off of the closed intake valves returns from the manifold at just the right moment to enter the cylinders and makes the engine more efficient by increasing the air pressure in the cylinders like a low cost turbocharger.” (Taking a breath) “Since the speed of the valves’ opening changes with the speed of the engine, the time of shockwave’s return must be adjusted to match the next valve opening.” “The only way the change the timing of the wave is to change the size of the intake manifold, which is what this system does.”

(So you can see, a lot of research went into fixing this little engine…)

After a week of driving without chugging the Check Engine light has gone out. Yay!

End of story.

Thanks for reading.
Here is a photo as a gift to thank-you for spending your time reading this thread.