I have a 2001 4.2 V6 f-150 and the check engine light is on (code P1518) IMRC stuck open Bank 1.
I have searched for this problem and found a couple of posts but none of them helped me. I checked the vaccum lines as some guys said behind the battery....but mine seems to look good ... no pin holes. The post described it as a blue line...i only had a black one so did i check the right one??? but that the only vaccum line behind the battery anyways....

As far as locating the valves that open at 3000 rpm....i can't seem to find them, i know they are supposed to be at the rear of the intake manifold.....but its so tight in there and i can't even get my hands in there.....
Any help would be appreciated....thanks guys

 

IMRC's are simply ports that open much like a 4-barrel carburetor. At low Rpm's they stay closed and are opened by vacuum pressure as load increases. Here is a picture from a V-6. You can see the valves in an open stage.

IMRC Ford V-6

Unless you drive like an old man in Florida, you probably DO have a slight vacuum problem. I have seen this code many times in the past and vacuum lines going to the IMRC control or where they meet at the vacuum distribution usually causes it. You can't actually see the valves unless you tear it down. Go through your lines with a fine toothed comb and if you still don’t find a problem, try running a Sea Foam treatment through the booster line and in the tank to clean the shafts. If that fails, have your control tested.

 

Thanks for the pic..... so unless i take the upper and lower intake manifold apart.... there is no way i can free up the butterfly valves because they are inside...is that correct?
The vacuum line that i see on my engine are red .... but everyone said they are blue.... am i looking as something else.
I see the divider just behind the battery...and i followed that vacuum line all to where it splits again at the side of the intake manifold....(by the pcv valve area) and then goes behind the engine to the other side to the evaporator black canister. ... but it all looks good.
I still dont know where exactly the vaccum line meets with the IMRC.... is it on the side of the intake manifold...or is it on the back of it where i can't see it? Thanks a bunch for your help

 

The valves RARELY, if ever stick open to where a tear down is necessary. Again, I've never seen the problems where a vacuum repair didnt take care of it. If the shafts are carboned up, Seafoam or comparable fuel system cleanings will clear the crud. I don't have access to AllData today, but you might check under your hood for a vacuum routing diagram. I work on county vehicles that have 4.6 and 5.4L engines, so I can't tell you on a V-6. I will see if I can talk my neighbor into popping his hood on his V-6 when I get home and see what I can find.

 

I would greatly appreciate if u could check for me ...... some people say that the 2001 valves are electronicaly operated and not by a vacuum... but i have no clue......... thanks throttle

 

No luck with the neighbor being home, but I was able to research it further in AllData. The Intake Manifold Runner Control (IMRC) on a 2001 4.2L is in fact an electric controlled actuator/servo. Sorry I don't have a picture, but it's in the front, top center of the engine. Look directly in front just below the intake tubes. Just below left of the pressure regulator you will see a square box with bolts at the Four Corners. It has what looks like a **** on the top left and a bundle coming out on the passenger side. It's electronically controlled and actuates above 3,000 rpm's.

 

I have the same problem with my f150 1999 v6 code p1518 where you described the center in front of the intake manifold I see the the square box to the left. Question, a year ago I
had a vacuum leak it was below the center where the control is for flow in front of the intake manifold it was underneath that area, it was a vacuum line that came from the back of the engine to the front, the leak was a rubber elbow going up the top. It had a pin that
went up to the intake manifold I repaired it
because I could not find the part to replace it,can that cause the problem Robear1

 

Rather than start a new thread, I thought I would append to this one.

I have a 2001 F150 with 265,000 miles on it. Code P1518 just showed up. The data indicates the ‘Intake Manifold Runner Control is stuck open’.

I just had the truck in the dealership for the 5,000 mile service. A couple of days afterwards, the engine started running better than it had in years. I could tell the fuel economy was much higher. I went on a 600 mile trip and got 20 MPG from it. This engine has been at 14 MPG for as long as I remember. The day after my trip was when the P1518 code showed up. I researched the code and find bad idle and other symptoms. Seeing as the engine is running so good, should I spent the $800 to fix it? Could I cause other damage to the engine if I don't fix it?

Thanks,

Bill

 

I would get it fixed. Sounds like the truck is treating you pretty good.

 

Thanks for the advice. It has been a good truck. It drives and runs like new, more or less but repairs are expensive. I have a trans leak that will cost $900, a rear main seal leak for another $2500 and now this at somewhere between $800 and $1,000. I'm having a hard time agreeing to pay these costs to keep it in tip top shape. I've never had good luck with independent shops although their cost is much better. Thing is, I was ready to buy a new truck last month until the sales woman pissed me off like no sales person has ever done. I was ready to buy a Toyota after being a loyal Ford customer for 31 years.