Greetings all. First of all, thanks for all the great info on this forum. It has helped me greatly.
A brief history- I did the lower intake manifold gasket replacement recently with good results but have had an ongoing slightly rough idle and poor mileage. Noted that both IMRC units were going into the open position (for over 3000 RPM) with only slight increase in RPMs above idle. With a vacuum tester both IMRC units work just fine. With the tester on one of the vacuum lines to the IMRC units I noticed that the vacuum would drop from approx. 22 at idle to zero with only slight increase in RPMs. Same for both IMRC units. This has made me conclude that the problem is the actuator (solenoid?) unit on the back of the intake plenum.

My question- Is that a sensible conclusion? And if so, what is the part number? Also does anyone know if this is a part that is available after market or will this mean a trip to the dealership? Thanks.

Hi
sounds like a fairly reasonable idea to me. My solenoid failed after my lower gasket repair. I did wash down the engine compartment fairly thoroughly and might have gotten the solenoid wet, destroying the small paper-like filter that it has. If you want one it is a dealer item. My local dealer had never sold one, so I guess they are pretty reliable. Ford number is: F1HZ9H465A. I ordered from y2kford.com for $38.74. Your local dealer will want $53.80. Y2k ground shipping is $9.
Changing it out is a bit of a pain. I had to kneel up on the radiator housing, and blindly remove the bracket on the back of the upper intake manifold. It holds the IMRC solenoid and the EGR control solenoid. The IMRC solenoid just snaps onto the bracket.

On a side note: my idle was not that great for a while after too. I am now about 6 weeks post job and my '96 with 144k idles warm at 600 RPM smooth.

Good luck

Thanks for the response. Hopefully I will be able to get one from the dealership before I have to put the cowl back on.