Cleaned MAF/TB, replaced IAC, FF . . . now what?

[studio460]

2003 N/A Mercury Marauder 300B:

1. Cleaned MAF.
2. Cleaned throttle body.
3. Replaced IAC with a new Hitachi unit.
4. Replaced fuel filter with new (stock) Purolator filter.
5. Replaced spark plugs about one year ago.
6. Disconnected battery to reset EEC.

Symptoms:

Before replacing the IAC (idle air control valve), the car would die as soon as it was engaged into gear. After replacing the IAC, it no longer dies when engaging the transmission, but still exhibits these same additional symptoms as before:

A. Idles fine at about 700-800RPM (a little lower than "normal" as I recall).
B. Revs fine throughout RPM range in neutral.
C. Revs fine above 1,500 RPM to redline in-gear.
D. At low RPMs (between 700-1,400), and only when the transmission is engaged, there is a loss of power, and feels "rich." In neutral, low RPMs are fine.

I can't seem to detect any misfires--all cylinders sound like they're working. No other anomalies are apparent at higher RPMs. The car is mostly stock (stock TC is still in place, despite sig) with a very conservative, custom-tune (performed some years ago). One cat was drilled out about a year ago--the other is still installed. The car has since been running fine. These symptoms occurred slowly, over the course of about two or three days, as it got progressively more noticeable.

Any ideas?

[studio460]

So, since one of the cats have been drilled out (over a year ago), I'm thinking it may have taken a toll on the rear O2 sensor, or maybe the EEC's not happy with one drilled cat, and one intact cat. A quick phone call to my friend resulted in a possible diagnosis of one of the rear O2 sensors. I'd have to find my scanner to confirm. But my car's at 80K+ miles anyway, so maybe it's a good idea to replace the two rear O2 sensors anyway. Does anyone regularly replace all four?

[Mike M]

If the rear o2s are bad your check eng light would be on. The rear o2s are there to monitor your cats only. They are looked at by the PCM almost exactly the opposite way they look at the front o2s.
The PCM wants to see almost no changes in rear o2 voltage indicating a functional cat. If the cat stops doing its job then the o2 will provide voltage and your PCM will know the cat isn't working and throws a code p0420.

[Krytin]

EGR valve/differential pressure switch on my '04 CV w/2V motor had similar problems but it also tripped a CEL/code.

[fastblackmerc]

Is the MAF installed correctly?

Did you break the wire inside the MAF?

Is the MAF connected?

Are all the gaskets in good condition.

[studio460]

Thanks, guys! MAF looks good--wire intact. Couldn't get the rubber hose off of the PCV elbow--PCV valve "shakes" okay, so it's probably still good. The O2 sensors are stuck solid--can't get them off without a long breaker bar or something. Still haven't scanned the car. Still have no idea what's the source of the problem. Possible things remaining to check:

1. Check coil packs.
2. Check fuel injectors.

Any other suggestions?

[studio460]

EGR valve/differential pressure switch on my '04 CV w/2V motor had similar problems but it also tripped a CEL/code.
Hmmm . . . I wondering about that--lemme check the EGR. Is there a way to see if it's good before I buy/replace the part? Looks like its generic part number is "EGV1046," and costs about $90. My check engine light isn't on, but I believe the code for a bad EGR is: P0401.

EGV1046:

http://www.summitracing.com/parts/smp-egv1046/overview/model/marauder

So, I would first need to test both the EGR valve and the EGR solenoid before buying new parts. I found a YouTube video on how to test the EGR valve (re-routing the EGR vacuum line), and solenoid (using a Volt/Ohm meter), but the person in the video found that in that particular car's case, one of the cats got clogged, and the back-pressure caused a hose to the "DPFE sensor" to dislodge. Is a DPFE the differential pressure switch you mentioned?

So, if my problem is EGR-related, it could be due to any one (or more) the following components:

1. EGR valve
2. EGR solenoid
3. DPFE (differential pressure switch)
4. Any of the hoses or electrical wiring connecting the above.

Sound about right?

[studio460]

If the rear o2s are bad your check eng light would be on . . .
Thanks! So, with no check engine light on, the rear O2 sensors are probably still good? But, if the front O2 sensors are "bad," they should throw a code too, right?

[Krytin]

DPFE. was the problem I had. It is part of the EGR valve on the 2 V. motor but separate on the 4 V. motor.

[studio460]

I just watched a YouTube video on testing for vacuum leaks (carburetor cleaner method). Gonna give that a try tomorrow. Is carburetor cleaner the same as throttle-body cleaner? (i.e., Will introducing it into a vacuum leak also stall the engine?)

[studio460]

DPFE. was the problem I had. It is part of the EGR valve on the 2 V. motor but separate on the 4 V. motor.
Good to know! Thanks for the info, Krytin!

[GreekGod]

If this is a Marauder, it has 8 ignition coils, not 2 coil packs. Have you scanned for codes?

=================

[studio460]

Ah, thanks! Haven't scanned for codes yet (no check engine light).

[studio460]

Anyone have any suggestions on a good code scanner to buy? Is the Snap-On 2500 too old for our cars?

[GreekGod]

http://www.scangauge.com/tips-and-tricks/using-performance-monitor/

[Marauderjack]

EGR valve stuck open.....mine did this awhile back!!:argue:

[babbage]

DPFE. was the problem I had. It is part of the EGR valve on the 2 V. motor but separate on the 4 V. motor.


You have this backwards, DPFE comes with EGR Valve on a 4v (Marauder)
On a 2v (crown vic) it is separate.

+1 replace EGR (which comes with DPFE) and your problem is fixed.

Old post Alert?

[studio460]

http://www.scangauge.com/tips-and-tricks/using-performance-monitor/
Looks bitchin'--thanks!

[studio460]

EGR valve stuck open.....mine did this awhile back!!:argue:
Thanks, Marauderjack! There's hope yet! Same symptoms? Revs fine at idle and at speed, but feels rich, with no power from idle to 1,500RPM (and almost dies when you put it in reverse)?


+1 replace EGR (which comes with DPFE) and your problem is fixed.

Awesome, babbage! I'm getting real excited, now!


So, if my problem is EGR-related, it could be due to any one (or more) the following components:

1. EGR valve
2. EGR solenoid
3. DPFE (differential pressure switch)
4. Any of the hoses or electrical wiring connecting the above.

Cool! Thanks, guys! Should I replace all three of the EGR components just so I'm "covered?"

[studio460]

Here's what I'm ordering at rockauto.com:

Emission : EGR Gasket
MOTORCRAFT Part # CG740 {#2W7E9D476AB, 2W7Z9D476AA} $14.99

Emission : EGR Valve
MOTORCRAFT Part # CX2059 {#6R8Z9D475AA} 3W4E-9Y456-A3E $91.79

Emission : EGR Vacuum Solenoid
STANDARD MOTOR PRODUCTS Part # VS63 {#F57Z9J459C, F63Z9J459AA, ZZM32035A, ZZM42035A} Terminal Type: Pins; Terminal Gender: Male; Number of Terminals: 2;Number of Hose Connectors: 2; Hose Size - Inches: 3/16" x 3/16"; Connector Gender: Female $25.79

Does this order look okay? And, I DO NOT have to order a DPFE as a separate part, since it's already part of the EGR valve assembly, correct? Thanks again for everyone's help!!!

[Krytin]

You have this backwards, DPFE comes with EGR Valve on a 4v (Marauder)
On a 2v (crown vic) it is separate.

+1 replace EGR (which comes with DPFE) and your problem is fixed.

Old post Alert?

Your right.

http://www.rockauto.com/getimage/getimage.php?imageurl=http%3A% 2F%2Fwww.rockauto.com%2Finfo%2 FSMP%2FEGV1046_PRIMARY.jpg&imagekey=1319752-0&width=450
This is the part you need - Rock Auto is the place to get it!

[babbage]

Here's what I'm ordering at rockauto.com:

Emission : EGR Gasket
MOTORCRAFT Part # CG740 {#2W7E9D476AB, 2W7Z9D476AA} $14.99

Emission : EGR Valve
MOTORCRAFT Part # CX2059 {#6R8Z9D475AA} 3W4E-9Y456-A3E $91.79

Emission : EGR Vacuum Solenoid
STANDARD MOTOR PRODUCTS Part # VS63 {#F57Z9J459C, F63Z9J459AA, ZZM32035A, ZZM42035A} Terminal Type: Pins; Terminal Gender: Male; Number of Terminals: 2;Number of Hose Connectors: 2; Hose Size - Inches: 3/16" x 3/16"; Connector Gender: Female $25.79

Does this order look okay? And, I DO NOT have to order a DPFE as a separate part, since it's already part of the EGR valve assembly, correct? Thanks again for everyone's help!!!


I don't think you need #3 Vaccum Solenoid. Correct you don't have to get a DPFE as it comes with EGR. You can save a few bucks by getting it on RockAuto like Krytin said.

I've found it's a lot easier to remove the upper intake cover, remove and replace EGR, then connect EGR pipe to EGR, lastly put upper intake cover back on. It can be tough to thread the EGR pipe into the new EGR.

Kudos to you for doing it yourself! :burnout:

[studio460]

Awesome! Thanks, guys! Yeah, I don't think I'll order the solenoid--just the UFO thingie.

[studio460]

Before ordering the new EGR/DPFE, tonight I tried this quick experiment:

1. Removed short, 5" rubber hose line (is this the vacuum line?) from the lower nipple of the existing EGR, and plugged it at the end terminating below the upper harder-to-access nipple, leaving the lower nipple, open. The car started, and idled fine, but exhibited the same low-RPM, no power/too rich/almost-stalling-in-reverse symptoms.

2. With the short hose going to top of the EGR still plugged, I then also plugged the lower nipple: after turnover--immediate stall.

Is this any sort of valid "test" for the existing EGR/DPFE?

[Richy04]

If you have a tune, some tunes will not display a check engine light for:

1. O2 sensor malfunction
2. Coil Misfires
3. Trans issues.

I haven't seen a check engine light on mine since I bought it and a tune will not show many if any malfunctions because the parameters are set wider, things may be masked or turned off etc.. If you have a tune and can roll back to a stock tune, try that and see if she pops a light after its installed and done it's primary check of the system.

[studio460]

If you have a tune, some tunes will not display a check engine light for:

1. O2 sensor malfunction
2. Coil Misfires
3. Trans issues.

I haven't seen a check engine light on mine since I bought it and a tune will not show many if any malfunctions because the parameters are set wider, things may be masked or turned off etc.. If you have a tune and can roll back to a stock tune, try that and see if she pops a light after its installed and done it's primary check of the system.

Good point, Richy! I'd have to find my old tuner to return back to a CRD1 factory flash. Although I had a custom tune by Jerry of SCT (sometime in 2004-2005), the tuning software is locked-up in an old PC which no longer works. I'd need updated ProRacer software, plus a new license key from SCT since the tuner is still "married" to the old PC.

I just received my ScanGaugeII OBDII scanner today--no pending codes; no stored codes. Will receive a new EGR valve and gasket from rockauto.com sometime later this week. A custom X-gauge code is available for "EGR duty-cycle," but I have no idea at what percentage a nominal EGR duty-cycle should be.

[studio460]

SUCCESS!

And the winner is . . . the EGR! I just got my Motorcraft EGR/DPFE from rockauto.com this afternoon--I paid the extra premium for two-day shipping. Thank god, that was it! Can't thank you guys enough!!! Notes: You don't need to order a gasket separately--the Motorcraft EGR already comes with a new metal gasket, bolts, and washers. Also, I did not buy/replace the EGR solenoid. After installing the new EGR, ALL PROBLEMS DESCRIBED ABOVE DISAPPEARED!!! Thanks, guys!!!


EGR valve/differential pressure switch on my '04 CV w/2V motor had similar problems but it also tripped a CEL/code.

Krytin called it first!


EGR valve stuck open.....mine did this awhile back!!:argue:

Marauderjack--another winner!


+1 replace EGR (which comes with DPFE) and your problem is fixed.


Babbage--thanks a lot!

[Marauderjack]

Glad you got her fixed!!:beer:

[Krytin]

Yep, Glad you got it fixed.
Trivial point - when I had to fix the CV it was in San Diego w/my daughter when she was going to USD. I flew out for a parents weekend and picked up the EGR valve at the local NAPA and changed it out in her dorm parking lot!

[captain]

Save your receipt
My repalcement unit failed within a year. Good news...Life time warranty

[studio460]

Save your receipt
My repalcement unit failed within a year. Good news...Life time warranty

Thanks for the advice, captain! I bought a Motorcraft EGR from rockauto.com. It wasn't in a "retail" Motorcraft box--just a plain cardboard box. Should I just keep the rockauto.com receipt? Is it Motorcraft which offers a lifetime warranty on the EGR? How exactly does that work?

[studio460]

I had to dig through the recycle trash--I found the Motorcraft box. There is a "retail" Motorcraft sticker on the top of the "plain" cardboard box.