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5.0 manual...stalls when coming to a stop or quick deceleration...also rough idle...

  • Thread starter Thread starter killer5.0
  • Start date Start date Dec 20, 2009
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killer5.0

5 Year Member
Oct 8, 2009
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Dec 20, 2009
#1
  • Dec 20, 2009
  • #1
had this problem for since a bought the car a few months ago...ive done some searching and reading but alot of ppl are having problems with it stalling while idling...my idle just goes up and down and sometimes drops out until its warm...but even when warm when i decelerate quickly or come to a stop 9 out of 10 times it will stall and its embarrassing plus annoying. here is a quick list of mods (all done b4 i bought the car so i may be missing a few i dont know about yet)

gt40 upper and lower
f303 cam
underdrive pulleys
200a alternator (i put in)
bbk fender mounted air intake
70mm throttle body
70mm MAF
bbk fuel pressure regulator
bbk shorties
straights to borlas dumped just b4 rear axle
short shifter
3.73

i know it needs a speedo gear since im off about 12mph...i bought the one i need but haven't put it in yet...was wondering if that would mess with the VSS?

any help would be great...
thanks
 

liljoe07

5 Year Member
Feb 18, 2009
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Cartersville,Ga
Dec 20, 2009
#2
  • Dec 20, 2009
  • #2
Do you have a VSS code stored?

I would run the codes and see whats up.
 

killer5.0

5 Year Member
Oct 8, 2009
725
83
59
Dec 20, 2009
#3
  • Dec 20, 2009
  • #3
i need a tool to run the codes i presume? i dont have one...i guess my mechanic could do it
 
G

Georgia306

New Member
Jun 7, 2009
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Panama City Florida
Dec 20, 2009
#4
  • Dec 20, 2009
  • #4
Clean your idle air controller with carb cleaner or just get a new one. They get dirty and make your idle do what you are explaining. My 92 did the same thing and I had to get a new one. Hope this helps

Chris
 

killer5.0

5 Year Member
Oct 8, 2009
725
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Dec 20, 2009
#5
  • Dec 20, 2009
  • #5
okay thanks....ill try it
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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Dec 20, 2009
#6
  • Dec 20, 2009
  • #6
Agreed with Joe.

In your searching, I'm sure you've seen information about retrieving codes or buying a 30 dollar code reader.

Good luck.
 

killer5.0

5 Year Member
Oct 8, 2009
725
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Dec 20, 2009
#7
  • Dec 20, 2009
  • #7
30 dollar reader? i always thought they were a few hundred dollars...where can i get one?
 

liljoe07

5 Year Member
Feb 18, 2009
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Cartersville,Ga
Dec 20, 2009
#8
  • Dec 20, 2009
  • #8
Do a search for "surging idle checklist". You will find that you dont need to spend any money on a code reader. A test light and paper clip will get you the codes.
 

killer5.0

5 Year Member
Oct 8, 2009
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Dec 20, 2009
#9
  • Dec 20, 2009
  • #9
cool ill check it out
 
F

frankeeski

New Member
Dec 2, 2009
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2
Dec 21, 2009
#10
  • Dec 21, 2009
  • #10
X2 on the VSS (Vehicle Speed Sensor). The speedometer works off the mechanical part of it and the computer gets it's reading from the electronic part of it. It will do exactly what you are describing if it has stopped working or is working intermittently. Note that the speedometer will still work so don't discount this as a cause.
 

629RWHPstang

New Member
Apr 28, 2009
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0
1
NY
Dec 21, 2009
#11
  • Dec 21, 2009
  • #11
i had the same thing and was just a small vacume leak
 

killer5.0

5 Year Member
Oct 8, 2009
725
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Dec 21, 2009
#12
  • Dec 21, 2009
  • #12
where is the vss located?
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
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Cartersville,Ga
Dec 21, 2009
#13
  • Dec 21, 2009
  • #13
It hooks to the speedo cable on the side of the trans.

Just run the codes and it will tell you if you have a VSS issue.
 

stykthyn

I want to measure mine. It doesn't look that tall.
15 Year Member
Jul 6, 2006
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Dec 21, 2009
#14
  • Dec 21, 2009
  • #14
sounds like a vacuum leak or really crappy timing. that code reader is a life saver. I got mine off ebay for 20 shipped and it has a digital display so I dont have to count blinking lights.
 

killer5.0

5 Year Member
Oct 8, 2009
725
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Dec 21, 2009
#15
  • Dec 21, 2009
  • #15
is it any code reader or ones specific to fords/domestics?
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
363
124
Cartersville,Ga
Dec 21, 2009
#16
  • Dec 21, 2009
  • #16
If you MUST buy a code reader, just get the OBD1 code scanner.
 

killer5.0

5 Year Member
Oct 8, 2009
725
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Dec 21, 2009
#17
  • Dec 21, 2009
  • #17
i found this one.... http://cgi.ebay.com/ebaymotors/Equu...Z370307833896QQptZMotorsQ5fAutomotiveQ5fTools

ok ill check out the obd1 thanks
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Dec 21, 2009
#18
  • Dec 21, 2009
  • #18
A code scanner is not useful on an aero fox. A reader like the one listed is all that's needed.

I like that reader because it's easier than counting flashes. It's frustrating to help someone fix their car when incorrect codes are reported because the flashes were not counted correctly.

A 3145 has an LCD screen if you'd prefer.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Dec 21, 2009
#19
  • Dec 21, 2009
  • #19
Can't beleive this hasn't been asked, but what year is this car?? Is it a converted SD to MAF car? Or is it an 89+ that has always been MAF?

#1 suspect to me would be the VSS, but if it's a converted SD car without cruise control, then it won't have one and this is a good probability why it stalls out.

Second guess if the VSS checks out is that you have a small vac leak int he brake booster or elsewhere.
 

killer5.0

5 Year Member
Oct 8, 2009
725
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Dec 21, 2009
#20
  • Dec 21, 2009
  • #20
sorry my bad...its a 1993 5.0 GT
 
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