Help!!!!!! (air/fuel ratio)

[jasonh_86]

I need some help with my car, so if you know anything that might help let me know please.


I had my car put on a dyno yesterday to check my A/F Ratio. At idle it was sitting at 18.0!! It didn't drop til nearly 4800rpm's and it never went below 16.1.

What can I do to make it not as lean?? I know I neeeed a tune, but I don't really have the money for a tuner/tune right now and probably wont for a while. Can I get a fuel pressure regulator for my car and up the psi and help solve the problem and where can you find one of those?? Or maybe bigger injectors??

Any info will be appreciated

It's for a bolt-on '02 GT 5-spd, by the way. (Mods in sig)

Please help me out Stangnet!!:SNSign:

 

[helty]

buy an srt-4













....or Camaro

 

[jasonh_86]

buy an srt-4

....or Camaro

Bastid!


What about a cobalt?

 

[helty]

you can't handle a cobalt

 

[trailblazr81]

Hows it running? Just bolt ons got you that far off and computer cant compensate? Is there something wrong with the car? I thought I read an article about a test with normal bolt ons and using a Predator the Mustang was a little on the fat side and liked it better that way.

 

[DBMSTNG]

i would bet a large sum of money that your car is just fine and that the dyno operator failed to properly calibrate the wideband 02 sensors. if your car was running 18.0:1 at idle, you'd have a check engine light.

 

[LI98GTStang]

Possibly because you have your Steeda T/A set too high? 16 degrees seems 1-2 degrees too much from what I've seen most people set it at on 99+ stangs.

 

[jasonh_86]

I did have it at 14*, then i changed it to 16* and it ran a bit stronger.. I've never had any pinging, hesitating, knocking or detonating from it, so I dont know.

I guess i'll back the timing down and lay off it until I can get a tune

 

[FalconGuy016]

It has been said that the MAC straight shot leans out your engine considerably.

 

[billfisher]

i wish i had your problem. one new bit of tech for the 3v. it likes LEAN. even the leanest tune is WAY too rich. i am fouling plugs at moderate loading. 30 psi fuel. jeez i gotta figure this out soon. maybe i can tape 2 of the four holes on the pintle on my injectors. maybe i can get a recurved maf. WOT it LOVES it. blowing suit. not too impressive for the friends. i allowed a small bypass of the maf to fool it, and it fixed it. i got rid of the factory maf. that's what i get. DOH!!!

 

[hotmustang331]

i would bet a large sum of money that your car is just fine and that the dyno operator failed to properly calibrate the wideband 02 sensors. if your car was running 18.0:1 at idle, you'd have a check engine light.

Funny thing, after I installed my cams we drove to GA for Tims tune. there Tim told me my cars idle A/F was @ 18-1...no CEL either . He didnt say the A/F, but I do know he shut it down mid run and then started tuning...so apparently it went way too lean. It was 14-15 before the cams, so I couldnt imagine. I would think a WOT A/F of 18-1 would melt the pistons, and he would no doubt hava ALOT of knock @ 16*s. Im also thinking that the A/F tool was jacked to an extent.

 

[billfisher]

uhhhuuhhhh.. he said 'jacked' hhhhuuuheeeheee

 

[CanadaStang]

Yipes, that's pretty lean. That's a perfect example as to why I always recommend getting a tune when you run nitrous!!

 

[CanadaStang]

Try cleaning your Maf sensor, a dirty sensor will lean out your a/f

 

[jasonh_86]

Well, i've been talkin to one of the mustang guys from around here.. a good friend of mine. He had me to back my timing down for a bit.. he also suggested a new MAF and maybe some bigger injectors if I wanted. So, I'm not sure what i'll do.

His A/F tool wasnt jacked, he did another car and it read perfect. He even reset the tool just in case it was a little off and it still read the same every pass my car made. He suggested removing my CAI and putting the stock one back on.

 

[FalconGuy016]

Well, i've been talkin to one of the mustang guys from around here.. a good friend of mine. He had me to back my timing down for a bit.. he also suggested a new MAF and maybe some bigger injectors if I wanted. So, I'm not sure what i'll do.

His A/F tool wasnt jacked, he did another car and it read perfect. He even reset the tool just in case it was a little off and it still read the same every pass my car made. He suggested removing my CAI and putting the stock one back on.

Probably good advice, the MAC straight shot leaned out engines a lot. Wait did I already say that in this thread?

Edit: lol yes

 

[CanadaStang]

Well, i've been talkin to one of the mustang guys from around here.. a good friend of mine. He had me to back my timing down for a bit.. he also suggested a new MAF and maybe some bigger injectors if I wanted. So, I'm not sure what i'll do.

His A/F tool wasnt jacked, he did another car and it read perfect. He even reset the tool just in case it was a little off and it still read the same every pass my car made. He suggested removing my CAI and putting the stock one back on.

Start with backing off the timing and cleaning the Maf sensor, with your mods the stock injectors should be fine.

 

[jstreet0204]

i would bet a large sum of money that your car is just fine and that the dyno operator failed to properly calibrate the wideband 02 sensors. if your car was running 18.0:1 at idle, you'd have a check engine light.

If you were running 18:1 at idle long term fuel trims would be at their limits and you would get a code. Check the plugs and see if they are showing lean. I would bet you are not off that much. A datalogger would be your best bet to check the fuel trims, but if you don't have one available, you can check your front o2 sensor voltage.


This is from the motorcraft service site, on obdii theory.

Fuel System Monitor​

As fuel system components age or otherwise change over the life of the vehicle, the adaptive fuel strategy learns
deviations from stoichiometry while running in closed loop fuel. These learned corrections are stored in Keep
Alive Memory as long term fuel trim corrections. They may be stored into an 8x10 rpm/load table or they may be
stored as a function of air mass. As components continue to change beyond normal limits or if a malfunction
occurs, the long term fuel trim values will reach a calibratable rich or lean limit where the adaptive fuel strategy is
no longer allowed to compensate for additional fuel system changes. Long term fuel trim corrections at their limits,
in conjunction with a calibratable deviation in short term fuel trim, indicate a rich or lean fuel system malfunction.​

 

[jasonh_86]

Thanks for all the advice guys, keep it comin!

Start with backing off the timing and cleaning the Maf sensor, with your mods the stock injectors should be fine.

I figured the stockers would be enough, I mean i'm only makin 259rwhp so I don't see how they'd be maxxed out that quick.

How do you clean the MAF? I may do that today.

I backed my timing down to about 14* last night, it smells worse of gas when it's just sitting there still. (like it did before I bumped the timing up to 16*)

It runs a little smoother now, but I didn't feel like I lost any power. So, I figured maybe that was leaning it out somehow, but i'm not quite sure. My SOTP-meter noticed a smoother power that was the same basically

 

[CanadaStang]

Thanks for all the advice guys, keep it comin!




I figured the stockers would be enough, I mean i'm only makin 259rwhp so I don't see how they'd be maxxed out that quick.

How do you clean the MAF? I may do that today.

I backed my timing down to about 14* last night, it smells worse of gas when it's just sitting there still. (like it did before I bumped the timing up to 16*)

It runs a little smoother now, but I didn't feel like I lost any power. So, I figured maybe that was leaning it out somehow, but i'm not quite sure. My SOTP-meter noticed a smoother power that was the same basically

Here's a link to cleaning the Maf sensor:
http://www.bullittarchive.com/html/m...icle.php?id=77

I'm surprised you didn't get any pinging when your timing was at 16.