• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

Need help

  • Thread starter Thread starter mustangmike01
  • Start date Start date Oct 5, 2005
M

mustangmike01

New Member
Oct 5, 2005
15
0
1
Holmes, Ny
Oct 5, 2005
#1
  • Oct 5, 2005
  • #1
Hay I'm new to the site names Mike. I need some help with my car.
At idle the car sounds like it has cams in it, but it dose not. The idle is moving from 800 to 1,000rpm. It should read 1,000rpm. If I come to a stop, it goes down to 400rpm and I can put my foot on the gas pedal to the floor and nothing. About 20 secants later it goes up to 1,000 and shacks. The car is shaking like crazy. The motor is shaking and the fuel gauge is moving from 25 to 35 psi. It should be at 30psi. I give it a little gas and it smooths right out. What could it be? I think is a one the idle sensors. I drove the car yesterday, I started it up and it ran fine. It stayed at 1,200rpm as it warmed up, no shaking. I gave it gas to rev the motor to 2,000 rpm and took my foot off the gas. The rpms dropped to 300rpm and slowing went to 800rpm and it was shaking. So what do you all think it is?

Here is a list of some of my mods, if it helps.

saleen s/c 10psi, cia, 75 tb, duel msd ignition, aero fuel rails, 42lb jets, bbk 255 fuel pump, diablo chip, jba short headers, bassani hi-flow cat & X pipe, roush exhaust, cobra flywheel, mcloud clutch, 6sp tremeic trany, b&m ripper 3:73 gear

Thanks, Mike
 
R

Red2000GT

Founding Member
Sep 10, 2000
2,450
0
46
Regina,Sask.Canada
Oct 5, 2005
#2
  • Oct 5, 2005
  • #2
I had to read this a few times over to figure out what you said but I think I've got the idea. It sounds like your Mass Airflow Sensor (MAF) is not adjusted to the 42lb injectors. Did you get a new one with the Saleen kit or does it adjust it within the computer itself? The changing fuel pressure is a big clue to that.
 

twogts4us

15 Year Member
Apr 1, 2004
4,188
12
79
Dunedin, FL
Oct 5, 2005
#3
  • Oct 5, 2005
  • #3
Red2000GT said:
I had to read this a few times over to figure out what you said but I think I've got the idea.
Click to expand...
Well, I figured out that ideal = idle, but WTF is shacking?
 

jcint

Member
Mar 30, 2005
168
2
16
wellington florida
Oct 5, 2005
#4
  • Oct 5, 2005
  • #4
major problems when your car shacks and it's ideal!
 
M

mustangmike01

New Member
Oct 5, 2005
15
0
1
Holmes, Ny
Oct 6, 2005
#5
  • Oct 6, 2005
  • #5
Red2000GT said:
I had to read this a few times over to figure out what you said but I think I've got the idea. It sounds like your Mass Airflow Sensor (MAF) is not adjusted to the 42lb injectors. Did you get a new one with the Saleen kit or does it adjust it within the computer itself? The changing fuel pressure is a big clue to that.
Click to expand...

The only thing I have from Saleen is the s/c and the intercooler. It's been running fine for the last 3,000 miles with the new tune and now it has a problem? I need to fix the problem because I'm selling the motor and the s/c. I need more HP.

Mike
 

streetstang03

unModerator
Dec 27, 2003
0
1
0
the dark side of the moon/home of the 1999, 2003,
Oct 6, 2005
#6
  • Oct 6, 2005
  • #6
mine was doing that when the IAC went out. try cleaning or replacing the IAC. its a cheap starting point to see if thats the problem. (~$50 at vatozone for a new IAC valve).
 

topless98gt

Adhesive Feces
Mar 31, 2005
182
0
17
Arlington, TX
Oct 7, 2005
#7
  • Oct 7, 2005
  • #7
streetstang03 said:
mine was doing that when the IAC went out. try cleaning or replacing the IAC. its a cheap starting point to see if thats the problem. (~$50 at vatozone for a new IAC valve).
Click to expand...
vatozone
 
M

mustangmike01

New Member
Oct 5, 2005
15
0
1
Holmes, Ny
Oct 7, 2005
#8
  • Oct 7, 2005
  • #8
streetstang03 said:
mine was doing that when the IAC went out. try cleaning or replacing the IAC. its a cheap starting point to see if thats the problem. (~$50 at vatozone for a new IAC valve).
Click to expand...

Yep, That's what I thought it was. IAC blow off two moths ago. I was running full boost up a hill for 2 miles. I just added to bolts and it work fine.

Thanks, I will clean it first this weekend to see if that's the propblem
 
You must log in or register to reply here.

Similar threads

B
'03 GT Fuel Pump/Pressure/Delivery Issue
  • Brodach
  • Oct 21, 2025
  • SN95 4.6L Mustang Tech
Replies
8
Views
805
SN95 4.6L Mustang Tech Oct 31, 2025
gkomo
S
Need help asap
  • shaggyman65
  • Dec 24, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
238
1996 - 2004 SN95 Mustang -General/Talk- Dec 24, 2025
shaggyman65
S
8
Engine Rough idle and aggressive sputtering when accelerating
  • 88vertible
  • Aug 13, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
1K
Fox 5.0 Mustang Tech Dec 13, 2025
Jarhead67
J
B
I need help with an 06
  • boviske underwood
  • Oct 30, 2025
  • Services - Tuning, Welding, Mechanic, Body Work...
Replies
0
Views
444
Services - Tuning, Welding, Mechanic, Body Work... Oct 30, 2025
boviske underwood
B
S
Fox '87 GT can't get to stay running
  • spilly
  • Mar 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
26
Views
561
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 25, 2026
CAMTWO1070
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?