Codes: P1537 and P0171

Just finished a troublesome repair on the ABS and thought we had this van back in shape when the "check engine" light came on. Got the codes read and it's pulling the following:

DTC (Codes)
P1537
Intake Manifold
Runner Stuck Open
(Bank 1)

DTC Pending (Codes)
P0171
System Too Lean
(Bank 1)

My questions are:
1. Are these two codes related to one another?
2. Is this a project for the driveway or the mechanic's shop?
3. If it's something that can be fixed in the driveway, can someone out there please give me a VERY detailed "how-to-fix-it" run-down for the beginner?
4. Is the van safe to drive in the meantime?

Thanks so much!!

Just finished a troublesome repair on the ABS and thought we had this van back in shape when the "check engine" light came on. Got the codes read and it's pulling the following:

DTC (Codes)
P1537
Intake Manifold
Runner Stuck Open
(Bank 1)

DTC Pending (Codes)
P0171
System Too Lean
(Bank 1)

I'm half way through a similar repair except mine is bank 1 & 2. In my case the IMRCs are bad, I cleared the IMRC codes by rigging the runners closed (the position the should be in at running idle, opposite the off position) with some #16 aluminum wire (others have used springs) and plugging the vacuum lines to each runner controller with screws. Note that this is just a temporary fix as I cannot afford two new $250 vacuum actuators at the moment.

My questions are:
1. Are these two codes related to one another?

They weren't in my case. I still have the P0171 and P0174 codes. I have narrowed the cause down to a vacuum leak. In the newer Windstars I've read that it's a matter of replacing the isolator bolts that hold down the lower air intake manifold. Mine didn't have those ('98) but I did a similar repair, replacing all the gaskets and cleaning out the EGR ports. It didn't clear my "too lean" codes but it runs a whole lot better.

2. Is this a project for the driveway or the mechanic's shop?

If I can do it anyone can.

3. If it's something that can be fixed in the driveway, can someone out there please give me a VERY detailed "how-to-fix-it" run-down for the beginner?

This is the topic on the 0171 & 0174 codes:

http://www.automotiveforums.com/vbulletin/showthread.php?t=589239

This seems to be the definitive how-to on the repair, like I said, only if yours is a '99 or later:

http://leckemby.net/windstar/windstar01.html


4. Is the van safe to drive in the meantime?

Thanks so much!!

You'll just get rough idling and occasional stalls (someone correct me if it's not safe) I drove mine for a few weeks like that.

Thank you for your post. I was looking for that link to the leckemy site, but hadn't found it yet so that was helpful. Here's where we're at now: For the past few days, the "check engine" light has been off again. It seems to come on every week and a half to two weeks and stay on for a couple of days or so, and then it goes off again. What is that telling us? My husband figured that he's just going to have to wait until it comes on again to be able to troubleshoot, but we'd like to know what's going on so we can stop the on again/off again cycle with the light and get this van back in good shape.

Okay, our CEL light has been back on all week long now and so I am eager to get these codes taken care of. Regarding the P1537 (which I'm going to try to eliminate first) before the P0171, I am a MAJOR BEGINNER here. Can anyone out there either show me a picture of the IMCR or help me figure out what it looks like via that leckemby site or just simply give me a good, detailed description of where it is under the hood and what it looks like? I know that I am looking for a runner that is stuck open and possibly a broken clip causing the arm to be unattached, etc. I just need someone to point me to the IMCR!! After that, it should be easy. Thanks!!

Hi
First off, it is IMRC for intake manifold runner control. As you look at your engine from the front, cylinders 1,2,3 run left to right across the back, 4,5,6 across the front. Each cylinder has two ports for intake air that comes from the black upper intake manifold you can see mounted on top. One of those ports is normally closed (below 3000RPM) by a "butterfly" valve controlled by the IMRC. As you look at the engine, the IMRC valves are located on the left end of the engine with one forward and one rear for each cylinder bank (they are somewhat hidden when the upper intake manifold is on. )The forward one is just behind the alternator. It has an electrical connection coming in from the bottom and a vacuum hose on top. An aluminum arm projects down and forward and is attached, by a small plastic retainer ($6 ea. at Ford) to the intake manifold runner - Butterfly.
Wiswind has a lot of Windstar photos at:http://rides.webshots.com/album/201931518cScpNK?start=0

Take a look at photo 4 and 5 and you can see the IMRC's with the upper manifold off.

As you have the 1537 code, you should be dealing with the rear control. It looks a mirror image to the front control and is located exactly opposite, controlling the rear (bank 1) runner. Perhaps the retainer failed and the arm of the actuator is unattached. Others Have had the valves fail such that with vacuum pressure applied they did not move - normally the valves will have vacuum on them, holding them closed. I would guess the latter as your code indicates the valve is open, which is where it will be with no vacuum on the IMRC actuator. With a vacuum pump you can check the operation of the valve.
If you do need to replace one, rockauto.com is best. I recently ordered an aftermarket brand for $71. Based on their catalog, the rear is the LH, and the front is the RH. To order it on their site go to engine/intake manifold runner control
http://info.rockauto.com/RB/Detail2.html?http://www.dormanproducts.com/images/items/hwrap1/47097.jpg

Hope that helps

Thank you so much, busboy4, for taking the time to give such a detailed response! We love this site -- it has helped us fix so many things on this van that is constantly in need of some repair or another. I don't think we can miss this one thanks to your description and Wiswind's pictures....

So we looked at the two vaccume driven valves (IMRC) on the left end of the engine. The arms are attached as well as other necessary items. One question is, there is very little vaccume on the lines when the car is running. Does this seem to be a problem?

Also I moved the levers a little to see if stuck. The arms seem to touch the resting places where I assume it would be a natural spot when the car is not running. When the car is started the actuators do not move.

heeeeeeeeeeeeeeeeeeellp

So we looked at the two vaccume driven valves (IMRC) on the left end of the engine. The arms are attached as well as other necessary items. One question is, there is very little vaccume on the lines when the car is running. Does this seem to be a problem?

Also I moved the levers a little to see if stuck. The arms seem to touch the resting places where I assume it would be a natural spot when the car is not running. When the car is started the actuators do not move.

heeeeeeeeeeeeeeeeeeellp

Hi
the IMRC valves are spring loaded extended, which places the butterflies (in the intake manifold) open, where they should only be above about 2900 RPM. When you start the engine, vacuum applied to the valves should pull the arms in and move the internal valves to the closed position. As yours do not move, you are triggering the 1537 stuck open code as they should close with vacuum.

As you are only triggering bank one (rear bank) codes, I would start with the rear actuator. Many of us have had one of these valves fail to hold vacuum and therefore fail to operate. Unplug the rear valve's vacuum line and plug it. Start the van: does the front valve move now? If so, the vacuum loss is in the rear actuator itself. Fairly straightforward at that point: replace the rear valve - rockauto.com is the place for that.

If that test produces no change, then it gets a bit more dicey as you then have vacuum loss somewhere else, and unfortunately there are a lot of somewhere's.

Give that a go and let us know what you find. And, by the way, what year/engine are we talking about here?

I found that sucking on the other end of the vacuum hose works if you don't have access to a vacuum pump. If the actuator doesn't move or the line won't hold vacuum the IMRC is bad.

Another note, the vaccum source is the same to BOTH actuators, so 1 can have a leak, robbing the other of the needed vaccum.
You can remove and plug the vaccum line to one actuator, start the engine, and see if the one still connected closes.
If it does, the disconnected actuator is the bad one.
If it does not, then unplug the line and reconnect the 1st one, and remove and plug the line to the other actuator.

If this does not make the other one close when the engine is started....follow the vaccum line to the rear of the upper intake manifold.
It will go to a vaccum control solenoid......you can see them in my pictures, I posted a picture someplace in there of the back of the upper intake manifold, when I had it off the engine.
There will be a vaccum line going into the solenoid (passenger side, rear, of the upper intake manifold) and a line going out....along with an electrical connection.
The PCM sends a signal to the solenoid to interupt the vaccum to open the runners.
A damaged vaccum line, or loose vaccum line could be the problem....
Again, if it is not one of the actuators.