MY05GT

I got my Mustangs to a Dyno this weekend ( Club Dyno day 3 pulls $50 ).

Both cars are stock except for K&N in the 95.

Both did better than I expected, the 05 hit 272 HP/ 292 trq. The 95 hit 220HP/266 trq.

I am concerned about the Cobra because it has 153,000 miles and the A/F was high ( I believe it was 13-14, but it was definitely in the red )

Where should I start to rectify this problem?

Scothew

Joker or a few others here can correct me if I am wrong since I am not as versed on a 5.0 as I am 4.6's, but I believe you could get a adjustable fuel pressure regulator and add a bit more fuel pressure, should richen it up a tad. For a n/a car, i'd say 12.5-13.2 is about right for most.

The Rock 326

Can you post up the dyno graphs??

DrunkenDragon713

Someone had to do it!

joker

It would definitely be best if you could post up a graph. Knowing where it is going lean and seeing the a/f curve may help to pinpoint the problem. Also, a few questions that may effect finding the problem.

Have you changed to an aftermarket maf? If so what brand?
What plugs are you running?
What is your timing at?
Are you running any kind of aftermarket cold air induction kit? If so what brand?
When is the last time you had your fuel filter changed?
Is your fuel pump making any kind of noise?
What kind of air filter is in the car?
Do you have any kind of "performance chip" or ecc flash done on the cars computer? If so what brand?

joker

You are correct Sir.

I would definiltey recomend putting a pressure guage on the car at least, since it is having lean issues. Knowing what the pressure is might tell a little more about the source of the problem. An adjustable regulator can be used on the fox body cars to lean them out or richen them up a little, but I dont know about the 94-95 models since they have different ecc's. They are more picky about things like cam changes, and they are also are transmission specific. Where as a fox you can run an aod computer in a 5 speed car without any problem. So evidently there is at least some difference the in ecc's.

MY05GT

MAF appears to be stock

autolite platinum changed the day after I got it

I BELIEVE that it was at +14 ( this is above me, but the guy at the Dyno checked it ) if that does not sound reasonable I may be wrong

no CAI, but installed K&N on day 1 also

The fuel pump appears to sound normal, several club members listened to it as we thought that the fuel pump was a possibility on an earlier problem (car dying and not starting - ignition module)

unknown on chip, any way to check

MY05GT

My computer skillset leaves a lot to be desired so I can not post it up :bang:

Fortunately for me, several other club members post here and at least one of them ( who incidentally got the files to me ) has already posted his info.

HAMBOOOOOONE HEEEELLLLLLP!

If you could add this info for me so that I can get some more help I would appreciate it. Also, I do not know how to pull up A/F curve....maybe a little training also

Thanks

Hambone

Hi Chuck,

Here are you dyno shots

On your 05 run, it looks like A/F wasn't measured correctly...

O5GT Runs:
[attachmentid=44086]

Hambone

And here is your Cobra sheet---notice the A/F on it being what I think is "on the lean side"...

[attachmentid=44087]

Nice numbers from both cars, dude!

Scothew

Ok yeah thats alot higher on the a/f than the 13-14 he stated. Yeah defintely needs more fuel in it.

Hambone, could you e-mail me his run files so I can get a better look at the A/F.

Scothew (at) themustangsource (dot) com

MY05GT

Thanks for the help. I could not remember the exact numbers, don't know what it is supposed to be, but knew it was high. After reading about some of the modified 05s, I knew that was bad. Putting in injector cleaner tonight, but I do not have high hopes. Other than go back and throw it on the dyno, is there a way to see if it helped?

joker

Running that lean, the first thing I would personally do is put a fuel pressure guage on the car.

joker

As a second thought, I might would check the maf element to see if it was dirty as well. If it is you can clean it with some electrical parts cleaner. However, be very carefull as it can break easily. Whatever you do do not touch it with your fingers. The oil in your skin can cause it to read irradicly.

Has anyone heard of the oil from a k&n getting on the maf? I would think it would be possible if the filter didnt dry totally before it was installed, but I have never heard of it personally.