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JakeTheSnake 01-30-2013 03:51 PM

[SOLVED] Help me diagnose this engine problem?
2004 ZTS Sedan, 2.3L PZEV, auto-trans

A couple weeks ago I did the Stealth CAI mod based on BlazingCopper's writeup here:

It has been great!

However just today I fired up the car and it was sputtering & puttering - and the Check Engine light started BLINKING. I had not left the driveway, so I pulled it into the garage, shut it off, and looked up the blinking. A misfire condition... great. :(

I checked when I last changed the spark plugs - over 40k miles ago. I had a box of Autolite XP103s on hand, so I checked the gaps at .050~.055-ish, disconnected my battery, and installed the new plugs.

I reconnected the battery, fired it up - no Check Engine light at all - not solid, not blinking. I let it idle for a few minutes, then drove it to my nearest Advance Autoparts. It still had the sputter during the drive, but no Check Engine light, there & back round trip about 8 miles.

The guy at Advance plugged into my diagnostic port - no static codes (I had cleared them evidently when I disconnected the battery) and the live data all checked OK with the car sitting, at idle and held at 3k rpm for a minute or so.

He asked me to pop the hood with it running, and he stated it sounded like something was sucking air where it shouldn't - a vacuum line, intake manifold, etc. I noticed the hissing too - it seems to be coming from the passenger side of the engine compartment, so I guess it's not the sound of air moving thru the new Stealth CAI setup.

I took these three videos when I returned home, idling in my driveway.

Inside the car watching the tach:

At the tailpipe - oh yah sputtering!

Hood up, engine compartment:

Any ideas on what I should do next?



zetecDon 01-30-2013 04:33 PM

1 Attachment(s)
Moved to "General Technical Chat" to better help you.

Fattie 01-30-2013 05:58 PM

im guessing the COP is bad.

JakeTheSnake 01-30-2013 06:07 PM

One (or more) of the 4 Coil-On-Plug packs eh? I'm going to check those tomorrow - definitely buying new boots for them at least.

JakeTheSnake 01-31-2013 06:30 AM

Today I'm going to replace the COP boots, and clean the MAF sensor with CRC MAF Sensor Cleaner.


JakeTheSnake 01-31-2013 10:57 AM

I just bought this on Amazon:

I'll use it with my Windows PC and/or my Android devices via Bluetooth to help diagnose my car. It will be handy to have for all three of our vehicles.

I should have it tomorrow.

6SPD_soul 01-31-2013 05:09 PM


Originally Posted by JakeTheSnake (Post 4566386)
I just bought this on Amazon:

I'll use it with my Windows PC and/or my Android devices via Bluetooth to help diagnose my car. It will be handy to have for all three of our vehicles.

I should have it tomorrow.

Did you buy any add-on software? I don't know how useful that's going to be without it. It looks like without software you're only able to read/clear codes. I think I might buy from them also, but get the wired USB version and spend more on software add-ons.

EDIT: Nevermind, it looks like the base software package should be pretty useful.

JakeTheSnake 02-01-2013 01:27 PM

VERY useful!

I've only just used the OBDLink Android app during my lunch break, and I have a distinct path to follow now.

P2004 IMRC stuck open.

Doing some searches around here and the internet in general, this seems a very common problem that crops up shortly after installing a stealth CAI modification.

So when I get home this evening I'll check the IMRC according to my Ford Workshop Manual - Powertrain Control/Emissions Diagnosis 2004:On Board Diagnostics, Section 4, sub-sections HU15 thru HU41, IMRC troubleshooting steps.

JakeTheSnake 02-02-2013 01:40 PM


The Intake Manifold Runner Control is supposed to move the tumble flaps in one position at under 3k rpm, and the other position at 3k rpm and up.

My IMRC was sitting in the "relaxed" > 3k rpm position even at idle.

On top of the intake manifold are two solenoids - the driver's side solenoid turns vacuum on & off to the IMRC.

When the solenoid is open, the IMRC energizes, and puts the tumble flaps in the low RPM position. When engine RPM hits 3000, the PCM closes that solenoid, the IMRC loses vacuum, and it relaxes.

My IMRC wasn't energizing at low RPM for some reason.

I disconnected and checked vacuum lines in the system, reseated them; then checked and cleaned electrical connectors at the IMRC solenoid, the IMRC itself, and the Intake Air Control valve.

I reconnected everything, cleared codes in Key-ON Engine-OFF, & started it up.

The IMRC energized, the idle smoothed right out - I took her for a drive about 10 miles, all is well.

The ODBLink was the key - with that + the ODBLink Android app on my smartphone I had the data I needed to properly troubleshoot.

I'm an IT professional - gimme some data about what's happening and I'll fix anything. [headbang]

I wanted to change the Topic Title to "[SOLVED] Help me diagnose this engine problem?" - but I don't see the control for that... am I missing something?
I managed to change the Title of my first post, good enough I guess! Thanks all!

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