why am i still running lean?

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 25, 2005

#1

• Jun 25, 2005

• #1

ok, so i just did a aod to t-5 swap and let me tell u that i wish i had a t-5 in the first place. anyway, i used to hear popping with the aod and i thought it was the tranmission but it still hesitates and pops with the t-5 so i asked my friend/mechanic what it is and he said its misfire from running too lean. So i replaced the MAF sensor and that hasnt cured the problem. i also found out my exhaust towards the back was rubbing against the fuel line and i actually had to replace that and that made it run better. BUT like i said, it still pops and hesitates. Any other ideas? what can i do? thanks a lot guys!

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

Jun 26, 2005

#2

• Jun 26, 2005

• #2

Pull the diagnostic codes and see what they tell you about things.....

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#3

• Jun 27, 2005

• #3

thank you michael. thats the best idea i have heard so far!

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#4

• Jun 27, 2005

• #4

any other ideas? someone out that has to have had the same problem

 

B

Bramm

New Member

Apr 29, 2005

30

0

0

NW Pa

Jun 27, 2005

#5

• Jun 27, 2005

• #5

Pull the code's. the code readers 29 bucks at walmart. Since your lean look at fuel delivery. Fuel pump/injectors fuel filter. Are you sure your not gett'n detonation? check the timing.

Since you said your exaust damaged your fuel line i suspect fuel filter but its hard to tell.

I think the computer may also lean out the mixture if you have a bad or faulty o2 sensors? But thats where pull'n the codes comes in.

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#6

• Jun 27, 2005

• #6

thank you for the help bramm, woulda never thought of those things! i did recently (very) replace the fuel filter....and when the t-5 swap was done my mechanic/friend said he ran a fuel-system cleaner to clean the injectors....anyway i will get that code puller (thanx for the tip) from wal-mart and pull the codes..... and i will ask about the injectors and the fuel pump.... (ask my mechanic what he thinks)...something else that might have something to do with this...let me tell u...is that when the engine is cold and i just start it up and it is in neutral or in 1st for that matter... and i push on the gas...the car tries to DIE...i dont understand why...its like the engine is having trouble connecting to the tranmission (also had this problem with the AOD).....

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#7

• Jun 27, 2005

• #7

or at least thats what it feels like...so when i try and push the gas a little the cars RPM's actually drop!!!! wtf?!? anyway....the problem goes away after the car is warm, but it still.... i dont know what could cause that?
but when u get past that "certain point" and u push the gas pedal a little more to try and rev it to like 2000 it jumps up and doesnt try to DIE anymore!!!

all i have to say is

??????????????????????

someone please help me figure this out. i wanna go on a road trip to CA later this summer.

 

bullitstang1313

Member

Jan 21, 2003

713

0

16

Indianapolis / Columbus, Indiana

Jun 27, 2005

#8

• Jun 27, 2005

• #8

You might check to see if your O2 sensor wiring is okay. Mine got caught up on the h-pipe and burned through giving me erroneous readings.

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

Jun 27, 2005

#9

• Jun 27, 2005

• #9

If the O2 sensors are bad or the readings stop, the ecu drops into open loop mode - the same mode it's in during a cold start. In open loop the system runs richer, not leaner. It won't pull fuel to run leaner unless it has reliable O2 readings.

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#10

• Jun 27, 2005

• #10

so could i be experiencing the popping from running to rrich?

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#11

• Jun 27, 2005

• #11

i think we may have solved this one michael.... BRAMM SAID: I think the computer may also lean out the mixture if you have a bad or faulty o2 sensors? But thats where pull'n the codes comes in.

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

Jun 27, 2005

#12

• Jun 27, 2005

• #12

See my message again - no, the computer DOES NOT lean out the mixture if you have bad O2's or a faulty signal from them; it goes the opposite way, into open loop where it makes it richer.

But you are correct - quit guessing at it, and pull the codes first. That's always the first place to start.

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#13

• Jun 27, 2005

• #13

sorry i wasnt reading carefully, thanks a lot, i will update and tell you how it goes!!!

 

B

Bramm

New Member

Apr 29, 2005

30

0

0

NW Pa

Jun 27, 2005

#14

• Jun 27, 2005

• #14

yea, i couldnt remember if a faulty o2 sensor leaned out or richened up the mixture. Just a stab at possably somewhere to look. The code reader's worth the cash to have in your toolbox as long as you dont loose the manual with all the code definitions in it.

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 27, 2005

#15

• Jun 27, 2005

• #15

ok thx bramm, if anyone has any other ideas and wants to chime in, feel free!

 

W

wildstang87

New Member

Jun 9, 2005

96

0

0

Jun 27, 2005

#16

• Jun 27, 2005

• #16

sounds like a dead spot in the tps, you can check this with a volt meter. or unplug it, and drive it see if it still has the same symptoms. you will need to reset the ecm after you drive it so the tps code isnt stored. hope this helps.

 

C

custom89stang

New Member

Dec 9, 2003

705

0

0

Seattle, WA

Jun 28, 2005

#17

• Jun 28, 2005

• #17

ok thx, i'll give it a try!