• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Rough Idle Update


Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
I'm not sure if I'm supposed to start a new thread or post on my old one but anyway, I'm the guy with the 03 ranger 3.0 that has a rough idle. I took it in to the dealership today. They said their diaog shows the MAF(new from Advance) is giving a bad reading like my truck is at an elevation 4000 ft. above actual. I returned the MAF to advance for another one and the dealer then recalibrated the PCM but still no luck,truck still has a "quiver" as they called it.
They also did a compression test which was good. They suggest a motorcraft MAF ($216) to rule out the possibility of cheap reman sensors or drive the truck until the check engine comes on then bring it back in to them for free diaognostic. Their top tech said if he didn't know better he would say I have a misfire condition but there is no code so he is scratching his head. I am wondering what to do next. The advance guy won't give me a refund but will swap out the sensor one more time. What are the chances of 3 of their sensors being bad out of the box? What I need is a known good sensor to plug in just to test with. Maybe junkyard time? Sorry this so long.Help!!!
 


aeraceranthony

New Member
Joined
Aug 22, 2008
Messages
86
Reaction score
0
Points
0
Location
Torrance, CA
Vehicle Year
1994
Make / Model
Ford
Engine Size
3.0L
Transmission
Automatic
To rule out the MAF, start the truck. Let it idle. Unplugg the the MAF with the truck idling. If the the truck idles better than its the MAF. Also a check engine light should come on when you unplug the MAF. But plug it back in with the car off and the check engine light should come off next start.
 

Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
Thanks,gave it a try just now. Idle did not change at all but no CEL.I don't understand why.The truck actually idles worse than when I took it in this morning. $85 for this!!!




Anybody have a used oem maf for sale?
 
Last edited:

rurouni20xx

New Member
Joined
Jan 13, 2009
Messages
1,176
Reaction score
0
Points
0
Location
natchitoches, la
Vehicle Year
1993
Make / Model
Ford
Engine Size
3.0L V6
Transmission
Automatic
one problem here w/ the test, when i unplug my maf (or it falls off reading no airflow) my trk immediately dies, you have to have the maf connected for your trk to run last time i checked. on a side note, have you looked at your maf and seen if there was a layer of crap on it? i realize its new but is there a possibility theres some shipping material or something on it thats throwing the reading off? id clean it just to be sure, hope this helps...
 

Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
Picked up a used maf from the junkyard today. Truck idles rough like before I took it to the dealer(they made it worse). I reset the pcm with the used maf installed. At least it is back like it was. I got my $140 refund from advance and gave $50 for the used maf. Not sure what else to try though. Pulled one of the oxygen sensors but I don't have a way to test it. Can't tell much by looking at it. No matter which maf I had in there the truck would still run when I unplugged it and I would not get a CEL. Makes no sense.
The tech at the dealer said the truck is running lean. No codes. They can't fix it. If a CEL
comes on I get a free diagnostic. That's the best they can do.
 

Rearanger

Active Member
Joined
Feb 4, 2008
Messages
1,429
Reaction score
23
Points
38
Location
Southeast USA
Vehicle Year
2003
Make / Model
Ford
Transmission
Manual
The tech at the dealer said the truck is running lean.
How does he know? Did he use an exhaust gas analyzer? Lean burn condition is hard to ignite so could cause miss. When you first start it (cold) does it idle rough or just after it warms up? When engine is cold the system is running in open loop, only after warm up does it run closed loop and then O2 sensors would tell computer to adjust mixture.
 

Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
It idles ok at startup. I mean it might have a liitle bump to it but it is at high idle so it is hard for me to tell. I feel the roughness after the idle settles down. I don't know how the tech tested for lean condition. I assumed it was on the analyzer but I don't know.
I don't have much experience past the basics so are you saying the O2's might be the problem? Not sure I understood. I really appreciate you trying to help.
 

aeraceranthony

New Member
Joined
Aug 22, 2008
Messages
86
Reaction score
0
Points
0
Location
Torrance, CA
Vehicle Year
1994
Make / Model
Ford
Engine Size
3.0L
Transmission
Automatic
Whats the rpm after the truck warms up?
 

Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
700 rpm at warm idle. I tried a new idle air control valve today.Didn't help. The truck idled higher but still rough. Put 1/2 pint of seafoam in the oil and the other half in the gas and drove it 15 miles. No difference. Cleaned the good used motorcraft MAF that I put on yesterday with MAF cleaner. No better. Thinking about maybe putting on a new set of wires and maybe a coil pack even though I don't really think that the problem, the theory being that the culprit might be weak spark. Does anybody think it could be the pcm? I can unplug the maf and it will give a code for that or I can unplug the IAC and get a code for that but I never get a CEL.


EDIT: I even tried driving the truck with the MAF unplugged. It made the transmission shift very hard so I decided that weren't too smart. DIDn't get a CEL though.
 
Last edited:

timay67

New Member
Joined
Feb 9, 2009
Messages
2
Reaction score
0
Points
0
Vehicle Year
1993
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
700 rpm at warm idle. I tried a new idle air control valve today.Didn't help. The truck idled higher but still rough. Put 1/2 pint of seafoam in the oil and the other half in the gas and drove it 15 miles. No difference. Cleaned the good used motorcraft MAF that I put on yesterday with MAF cleaner. No better. Thinking about maybe putting on a new set of wires and maybe a coil pack even though I don't really think that the problem, the theory being that the culprit might be weak spark. Does anybody think it could be the pcm? I can unplug the maf and it will give a code for that or I can unplug the IAC and get a code for that but I never get a CEL.


EDIT: I even tried driving the truck with the MAF unplugged. It made the transmission shift very hard so I decided that weren't too smart. DIDn't get a CEL though.
I had the same problem, and went through the same steps you did. When I closed the hood the rough idle would get worse. Turns out it was the clamp/grommet on the end of the air intake tube coming out of the MAF. The grommet wasn't slid over the plastic tube enough and when I tightened the clamp it created a gap that allowed air in. It was underneath so I could not see it happening. I thought about checking it after a trip to a u-pull-it salvage yard and running across a similar issue there.
 

Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
Thanks,I will make sure to check that tomorrow. You are talking about where the intake tube meets the MAF housing , right? I have had that apart several times but I will double check it , especially under the bottom.
 

aeraceranthony

New Member
Joined
Aug 22, 2008
Messages
86
Reaction score
0
Points
0
Location
Torrance, CA
Vehicle Year
1994
Make / Model
Ford
Engine Size
3.0L
Transmission
Automatic
I will try getting the 02 sensors tested. I personal don't know how to do it, but it seems to be a possibility. Nest step after air will be spark and fuel.
 

Rearanger

Active Member
Joined
Feb 4, 2008
Messages
1,429
Reaction score
23
Points
38
Location
Southeast USA
Vehicle Year
2003
Make / Model
Ford
Transmission
Manual
so are you saying the O2's might be the problem?
I guess the 02 sensor(s) could cause lean burn. I'm not sure which side of mixture they tend to fail on - lean or rich. Maybe someone with more tech experience could add their thoughts. You can test them(it) I think you only need to test the one measuring mixture (Pre-CAT), not CAT performance.
 

Blackedge03

New Member
Joined
Mar 29, 2009
Messages
47
Reaction score
0
Points
0
Age
61
Location
Gadsden,AL.
Vehicle Year
2003
Make / Model
Ford
Engine Size
3.0
Transmission
Automatic
I swapped out the coil pack with the one on my wife's taurus(same). It didn't help.Going to have a mechanic with 30+ yrs. experience look at it end of the week. He says normally a vacuum leak is the culprit and that the 3.0's are usually smooth idling engines.
In the mean time I might mess with the O2's. Post back later. Thanks for the advice.
 

Toms01PSD

New Member
Joined
Feb 10, 2009
Messages
3,276
Reaction score
37
Points
0
Age
33
Location
Sanford, NC
Vehicle Year
2001
Make / Model
Ford
Engine Size
7.3
Transmission
Automatic
Try changing your plugs and wires. I just replaced mine yesterday because I had a misfire on #6. No more rough idle or CEL.
 

Sponsored Ad


Sponsored Ad

Staff online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top