98 Windstar IMRC Vacuum

[siliconbb]

I have a 98 Windstar 3.8 with what seems to be a IMRC problem.
Both IMRC units are open and when an external vacuum is applied to individual units the rear one closes but the front does not.
With engine running I close off the vacuum line going to the front unit and the rear unit closes but the vacuum line going to the rear IMRC has no vacuum. Is this normal?
I was going to replace the front unit, the one closes to the front of the vehicle, but was noticing in parts ordering they refer to them as Left and Right, which is which?
The van actually runs pretty good the only problem is a little hesitation on take off once in a while and at idle a slight mis.
Thanks for any insight.

[96wWindstar180K]

siliconbb
You probabley have a vacume leak. Leave hoses connected remove one at a time and with a vacume gauge check vacume. You should see aprox 15 to 21 in vacume. If not check for leaks. I had one hose that rubbed against a heater clamp and wore a hole in the back. Check for operation of the imrc by applying vacume with a vacume pump or a hose and suck on it and see if it moves the imrc. Also make sure it holds the vacume.

[siliconbb]

Thanks for the reply
Still searching for blasted leak. I know it's there because engine has a slight mis at idle.
1 IMRC is not working on vacuum.
FYI for anyone having same issues it seems the after market IMRC units are not working correctly. So Ford is raping for the part. $278

[wiswind]

The Right side of the engine should be the rear side, and the left side should be the front.
This is how it would be if the engine were mounted in rear wheel drive configuration.
There was a rear wheel driver version of the 3.8L (but they are NOT interchangable).

The leak in the IMRC may be from a defective diaphram inside one of the IMRC actuators.

With the engine at idle, CAREFULLY, disconnect and hold your finger over the hose, for one of the actuators and see if the other one moves as you place your finger over the end of the line and remove your finger.

Try this with both actuators, one at a time.
If one does not close and open as you place and remove your finger, then that is the defective unit.

The IMRC actuators are OPEN with NO vaccum, and they close with vaccum applied.
It seems backwards, but that is how they work.

[ibia22]

Follow this E-bay auction link and get a new unused OEM pair of IMRC motors for only $250 shipped! I bought a pair myself from the same guy last month.

The fix resolved my stall problem at slow speeds. But my '98 still has a slight miss at idle as well! There are so many hoses and so much noise under the hood; what is an effective way of finding a vacuum leak?

I have heard that some professional shops use a smoke machine.

[KCMike]

You may have answered your question in the your post.
>when an external vacuum is applied to individual units the rear one closes but the front does not.

This would tell you that the front actuator is leaking or stuck. Does it hold vacuum?


>With engine running I close off the vacuum line going to the front unit and the rear >unit closes but the vacuum line going to the rear IMRC has no vacuum. Is this >normal?

If you eliminate the leak caused by the front IMRC and the rear one closes then it must have vacuum at this point. That would indicate that the front IMRC is the bad guy causing the loss of vacuum to the rear.