New Mass Air Flow sensor making car run like crud

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nellenrob

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So I was having issues at cold start, and the codes pointed to the MAF. I replaced it and now the car wont hardly idle and is really having issues...Am I missing something?
 
You have to plug it in!

check that it is in fact seated correctly as far as the connector goes,
ensure there are no open leaks at the intake before and after,
possibly a damaged element on the new unit.

Swap back and forth on the new/old MAF to determine difference.

Put more effort into checking the intake all the way up to the Throttle body making sure it's not letting in any unmetered air.

Use an unlit propane torch flowing around intake to see if RPMs increase a little when looking for leaks. (no harm, not dangerous)


Always when swapping sensors, the battery terminals should be disconnected from the battery,
re-attached some 30 min later and allow it to reset it's idle mixture settings on start up.

Fuel filter and breather element.
 
ok, I reset computer and no luck. Put old MAF in and it runs "better" than with new MAF. Still sputtering when cold. I will have to follow up on the vacuum leaks...
 
Is the IAT built into the MAF on these cars... 03 ls V8... if not where is it located...
 
nellenrob said:
Is the IAT built into the MAF on these cars... 03 ls V8... if not where is it located...
Click to expand...


Everything you ever wanted to know about your 2nd GEN is available
in the online workshop manual located here: http://deneau.info/ls/

On 1st GEN it's sensor is located directly after the MAF,

2012-05-23_165618_1.gif


... not sure on your 2nd GEN, have a look at the manual.
 
nellenrob said:
Is the IAT built into the MAF on these cars... 03 ls V8... if not where is it located...
Click to expand...

Yes, the IAT is built into the MAF on gen II.

You probably have a post MAF air leak. That would explain the MAF code, and it running even worse with a new MAF.
 
Even look for something like this. Definitely sounds like it's getting unmetered air in.


attachment.jpg


What was/were the code/s ?
 
if you just swapped a bad maf and didnt follow the rest of the procedures you didnt do it right.
you very well may have a post-maf leak, but your pcm had already adjusted to that dirty old maf... putting in a new one isnt going to fix your problem until the old data stored in the computer is either sufficiently overwritten or completely cleared. i recommend completely clearing it. no need to keep old data bc all it is going to do is throw off the new data. follow the procedures to clear the kam via battery disconnect.follow the procedures to reset the kam after a battery disconnect. follow drive cycle procedures. if you are still experiencing the issue after completing the battery reconect procedures <and during the drice cycle procedures> THEN you almost certainly have a post-maf intake leak...
 
I'm having the same with cold start. Let us know what you find out.
 
Ugh, the jrant "drive cycle procedures must be followed to a tee" bullcrap again.

JUST DISCONNECT THE FN BATTERY CABLES ... RECONNECT AND DRIVE THE FN THING NORMALLY, IT RELEARNS ALL BY ITSELF!!!!!


jrant, I'm very surprised that after all this time with your relearn drive cycle horse sh*t, you still haven't found the part where it says in the shop manual that this is a process for dealership technicians to perform as to ready the vehicle for customer pick up and to aid in further troubleshooting of possible issues.


FYI: 99% of this forum thinks you are a fool with your "must follow drive cycle procedure to reset KAM" bible thumping!

soon as you start it back up, it begins to relearn all by itself. shift points will adjust, by the time you've had your breakfast it's done!




NOTE: Because the engine is electronically controlled by the powertrain control module (PCM), some control conditions are maintained by power from the battery. When the battery is disconnected or a new battery is installed, the engine must relearn its idle and fuel trim strategy for optimum driveability and performance. Allow the engine to idle for 1 minute. The relearning process automatically completes itself as the vehicle is driven. If the engine is not allowed to relearn its idle trim, the idle quality may be adversely affected until the idle trim is eventually relearned. Additionally, to account for customer driving habits and conditions, the automatic transmission must relearn its adaptive strategy. Optimal shifting resumes within a few hundred kilometers (miles) of operation...
Click to expand...


NOTE: When the battery is disconnected and connected, some abnormal drive symptoms may occur while the vehicle relearns its adaptive strategy. The vehicle may need to be driven to relearn its strategy.
Click to expand...



http://deneau.info/ls/s6x~us~en~file=s6x3e008.htm~gen~ref.htm << Re&Re Mass Air Flow (MAF) Sensor

^ ... where does it read to "MUST follow the jrant drive cycle to reset KAM settings"?





.... but WHATEVER!!!!! (don't look forward to a reply, same ol' same ol' :Bang )

 



http://www.counterpersontraining.co...ral/Sites/Global/File/standardfordrelearn.pdf

FORD VEHICLE COMPUTER RELEARN PROCEDURES

BATTERY OR BATTERY CABLE(S)

Any time the battery is disconnected, the
Keep Alive Memory (KAM) is erased. This
means that any learned values that the
PCM has stored for adaptive systems such
as idle and fuel trim will have to be
relearned in order to achieve optimum
driveability and vehicle performance. This
can be achieved by performing the idle
relearn first, and then driving the vehicle as
you normally would on a test drive, making
sure that everything is operating properly.


​
 
smart guy, go read the sht you copy/pasted: thats after a battery re-connect. did he disconnect his battery and reconnect? no! so he has the same old data in his 'kam' for the dirty old maf... so yes, the old maf will run better until you clear your kam. or you could let it sit there and run a whole tank of gas trying to get it to wipe over however many hours/miles worth of old, useless kam data... why waste your time with obsolete data? just clear it and initiate a relearn phase. its a simple concept. kinda like clearing your pc's caches, defragmenting, restarting the system... dont lose sight of the fact the car is computer controlled.
he should clear that sht and follow the battery reconnect procedure <different from a drive cycle procedure> BEFORE he goes on the wild goose chase trying to find the 'holy intake leak'
 
kinda funny that you guys are all against disconnect the battery... bigrig would probably give one of his littlerigs to not disconnect his ls battery

if it reboots and learns in an instant what do you got to lose littlewig?
"it starts doin weird stuff i dont understand"
"dont you guys know lincoln ls is controlled by an all knowing super computer that has caches that dump themselves and it is wise enough to dump 'bad' data and keep 'good' data? it is a 15 yr old standard bearer for super-computing, even to this day" ha
 
joegr said:
Just put him on your ignore list...
Click to expand...

I'm surprised BigRig hasn't put him on ignore already. Junior's been on my ignore list for years.

Nellenrob, what brand IAT did you get? If it wasn't a Motorcraft vehicle-specific this is probably the problem. The store brand generics are just that, generic one size fits none parts. When it comes to sensors, Motorcraft and Delphi are the only ones you want to use. Motorcraft is, of course, the factory Ford brand and Delphi is a general OEM supplier that generally makes parts for GM cars but does make parts for other brands as well.
 
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