3 problems 05 mustang gt need help!!!

JrS197

Junior Member
Joined
Jan 13, 2017
Posts
20
Reaction score
0
4 problems 05 mustang gt need help!!!

Some background on car: bought the car with 97k miles (from a well known local dealer) now at 101k, automatic, 100% stock, drive as my daily.

Problems

1) car idles at low 600 and every 10 seconds or less it drops to 500 for about 3-5 seconds and the entire car shakes then will go back up to 600, even on complete cold start it starts up and goes straight down to 600rpm. Started happening after i disconnected battery to reset check engine light i had for evap system dont think disconnecting the battery would cause this but since then its been happening. Also when its at 500 rpm and im not on the brake the car doesnt inch foward at all.

2) the transmission shudders sometimes. It only happens if i have been going at same speed for a while (usually more than 1 min) and i accelerate a little and it will shudder.

3) dont really know how to explain it other than the transmission feels as though it doesnt want to shift into the next gear or has trouble and when it does shift i hear a loud clunk and jerks the entire car foward, sometimes pretty violently. (Dont hear any other noises

4) The gas pedal has some play to it. Like first half inch it doesnt do anything, you have to push down about an inch or so for it to start going and sometimes even that has like a 2 second delay before it starts moving.

Could really use some help with these. THANKS!!!
 
Last edited:

JUSTA3V

Moar Throttle!
Joined
Jul 25, 2015
Posts
704
Reaction score
3
Location
Queen Creek AZ
clean throttle body and maf

Replace tranny fluid

How old are the plugs?

Accept that our gas pedals are drive by wire. If the play in to bothers you that bad, search on here on how to fix it. There is a thread
 
Last edited:

A John In NJ

Rice Cooker
Joined
Jul 1, 2007
Posts
858
Reaction score
1
Location
NJ
clean throttle body and maf

Replace tranny fluid

How old are the plugs?

Accept that our gas pedals are drive by wire. If the play in to bothers you that bad, search on here on how to fix it. There is a thread

^^^Exactly what he said!
 

46addict

13726548
Joined
Aug 25, 2016
Posts
1,832
Reaction score
56
Location
Lawrenceville, GA
If you had a code for the evap system there may actually be a fault in the purge solenoid or somewhere else down the line. If the code returns I wouldn't reset the battery until it's fixed.

When you change the plugs you should also change the plug boots even if they look good. They are $5 a piece from the parts store.

As for the gas pedal play, given that nothing is broken in the throttle body motor/gears and the gas pedal itself, a tune update can eliminate any play.
 

Boone

Automotive Enthusiast
Joined
Feb 24, 2015
Posts
320
Reaction score
4
Location
High Point, NC
First off, your problem is you can't count.. 3 questions?

1) throttle body
2) torque converter
3) torque converter
4) throttle body if since you "addressed" the code

Good luck with this. Hope it doesn't hit the wallet too hard.


Sent from my SM-G900V using Tapatalk
 

07 Boss

Senior Member
Joined
Jan 25, 2009
Posts
3,831
Reaction score
968
Location
Sin City
Most of the play in the pedal can be tuned out but there is some physical play that might still remain. A little lead tape on the arm will help as there may be some dead space at the beginning of the pedal travel.




Unhooking the battery for a period of time may have also erased the idle memory. It may take a week or two for it to relearn. Or you can go through the reset procedure.

The tranny may need a new solenoid pack. It is hard to diagnose without the right equipment. There are a lot of weak areas besides the bands in these transmissions. Could be worn servo bores, solenoid pack, could just be gummed up. Any maintenance records for this car?
 

JeremyH

3V Fuel Guru
S197 Team Member
Joined
Jan 10, 2009
Posts
20,857
Reaction score
197
Location
Virginia Beach
Look over all the vac hoses in the engine bay and make sure nothing is leaking etc.

Next go through the manual and do every maintenance listed for 100k miles.

I agree also clean maf and throttle body.

Things that you should do also on a 100k mile car outside regular interval stuff (oil, oil filter air filter) Especially if its a daily drier and you want to keep it reliable.

Coolant flush, transmission fluid change, new rearend gear oil. Fuel filter. Spark plugs and fuel injectors serviced.

Just cleaned the stock injectors on a buddy's 07 f150 5.4 3v with 99k on the clock a few weeks back and his car was instantly idling better and driving smoother. He called me other day to let me know he got 40 more miles on his last tank of gas than he normally gets as well.

Also a problematic thing for a higher mileage 3v is over time the oil from the pcv system gums up the charge motion control valves and can cause sporadic idle, driving issues. It wouldn't hurt to get in there pull the intake manifold and clean the plates/valves up as well.

A lot of these maintenance items can be done yourself with basic tools. If you are unfamiliar with this kind of stuff and want to learn there is a wealth of knowledge on this site to help you out.
 
Last edited:

bujeezus

forum member
Joined
Aug 31, 2015
Posts
3,251
Reaction score
355
Location
Alabama
Is servicing the fuel injectors something you can do yourself? Need any kind of special tools?
 

ha1234

Junior Member
Joined
Feb 8, 2017
Posts
25
Reaction score
1
Location
Atlanta, GA
Might not even be the whole throttle body, just the throttle position sensor. May also be a dirty MAF sensor
 

Norm Peterson

corner barstool sitter
Joined
Feb 5, 2011
Posts
3,615
Reaction score
316
Location
RIP - You will be missed
Most of the play in the pedal can be tuned out but there is some physical play that might still remain. A little lead tape on the arm will help as there may be some dead space at the beginning of the pedal travel.

That looks a whole lot less invasive and risky than disassembling the pedal sensor and tweaking the brushes. And the end result should be about the same (you would want to do the 'reset' procedure so that the ECU knows where "zero" and "100% WOT" are).


Norm
 

07 Boss

Senior Member
Joined
Jan 25, 2009
Posts
3,831
Reaction score
968
Location
Sin City
That looks a whole lot less invasive and risky than disassembling the pedal sensor and tweaking the brushes. And the end result should be about the same (you would want to do the 'reset' procedure so that the ECU knows where "zero" and "100% WOT" are).


Norm

Yeah it is a lot less invasive and pretty darn easy for the less mechanically inclined. You do have to weight the pedal down pretty good while you apply the tape as that pedal comes up pretty quick when the paving stone you have on there shifts and the pedal smacks the back of your head slamming your face into the bottom of the dash. Just a safety tip from the more experienced.
 

46addict

13726548
Joined
Aug 25, 2016
Posts
1,832
Reaction score
56
Location
Lawrenceville, GA
Is servicing the fuel injectors something you can do yourself? Need any kind of special tools?

The people that get paid to do injector cleaning use an ultrasonic cleaning machine and cleaning chemicals to bathe the injectors. It takes about an hour's worth of work from what I read.
 

Norm Peterson

corner barstool sitter
Joined
Feb 5, 2011
Posts
3,615
Reaction score
316
Location
RIP - You will be missed
Yeah it is a lot less invasive and pretty darn easy for the less mechanically inclined. You do have to weight the pedal down pretty good while you apply the tape as that pedal comes up pretty quick when the paving stone you have on there shifts and the pedal smacks the back of your head slamming your face into the bottom of the dash. Just a safety tip from the more experienced.
Cautions noted for if I ever need to do this. Thanks.


Norm
 

46addict

13726548
Joined
Aug 25, 2016
Posts
1,832
Reaction score
56
Location
Lawrenceville, GA
(you would want to do the 'reset' procedure so that the ECU knows where "zero" and "100% WOT" are).


Norm

Wouldn't the reset procedure negate the whole purpose of the mod? If the ECU knows the "pedal slack" has been taken up, it will acquire a new zero based on the new position. Or am I misunderstanding this?
 

Norm Peterson

corner barstool sitter
Joined
Feb 5, 2011
Posts
3,615
Reaction score
316
Location
RIP - You will be missed
I doubt that it can determine the new 'zero' without going through the procedure because the ECU only understands voltage input and would not know where the new zero really was at. In addition to the new voltage at 'zero', it may also need to be told what the new voltage range between the (new) zero and max positions is. It can't upset the mechanical mod, which only serves to eliminate any physical 'dead bands' at the beginnings of the resistance traces inside.


Norm
 

07 Boss

Senior Member
Joined
Jan 25, 2009
Posts
3,831
Reaction score
968
Location
Sin City
Wouldn't the reset procedure negate the whole purpose of the mod? If the ECU knows the "pedal slack" has been taken up, it will acquire a new zero based on the new position. Or am I misunderstanding this?

No, the pedal slack taken up is a physical, not electronic. But lets say you adjusted the pedal or brushes too far and you actually have voltage at zero pedal position. It will adjust that voltage to be zero on the pedal. When you do the pedal learning it takes the voltage at zero throttle and sets that as the bottom of the range.
 

Latest posts

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Sponsor Links

Banner image
Back
Top