• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

Idle Problem

  • Thread starter Thread starter STOCK94
  • Start date Start date Jun 6, 2017

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 6, 2017
#1
  • Jun 6, 2017
  • #1
Ok fellahs Ive looked through old posts and cant find an answer besides maybe mass air meter, my car is a little different than the regular 94GT. I have a Factory Five Cobra with the 1994GT running gear including ECU. The engine has TFS top end kit with B-303 cam, BBK 75mm TB, Granatelli mass air with 24lb injectors, also a MSD 6A ignition. Couple a weeks ago I installed a Vortech base kit to start with, the car runs pig rich and surges at idle but off idle it drives descent just rich.
I removed the blower belt and the car cleans its act up and idles, also a little leaner, its as if it were the same as before blower install. I put the belt back on and same old thing rich and Smokey. The Mass air meter is in front of the blower and then the IAT sensor is right behind it then the blower to TB.
The previous owner of the engine and harness has a mass air modifier installed, I cranked the idle knob all the way to the bottom and its a little better but still rich and surging but not as bad. Makes me think TB and its readings have to do with problem. Any suggestions anyone? Is it something a tune can fix?
 

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 6, 2017
#2
  • Jun 6, 2017
  • #2
Also new 1 step cooler plugs were just installed and gapped to 35
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,950
10,589
203
polk county florida
Jun 6, 2017
#3
  • Jun 6, 2017
  • #3
Lets get a couple guys that may be able to help in here.
Although I must warn you granatelli stuff is not a favorite.
@a91what @srtthis
 

srtthis

the guy doing it does every local racers rear end
15 Year Member
Jul 3, 2009
5,129
1,666
204
Maryland
Jun 7, 2017
#4
  • Jun 7, 2017
  • #4
with out really getting my hands on it id say its a combo of that Granatelli mass air... B cam... and the not cam friendly 94-95 computer
 
Reactions: STOCK94

a91what

SendMeUrDataLog
10 Year Member
Apr 6, 2011
10,739
6,721
214
Hillsborough county
Jun 7, 2017
#5
  • Jun 7, 2017
  • #5
I have to agree, the issue I am imagining is the turn on the pipe for the intake to the SC.

How does the mass air mount? Is it in the piping or does the filter slam on the end.
 
Reactions: STOCK94
R

RioRed95Cobra

Active Member
Apr 7, 2017
180
17
28
Jun 7, 2017
#6
  • Jun 7, 2017
  • #6
The IAT needs to be removed and relocated to BEHIND the supercharger.. and directly BEFORE the throttle body.

You are getting false readings off that IAT because the air is metered and such long before the supercharger compresses the air and heats it up/forces it into the intake. Your computer thinks the air is cold and therefore could throw more fuel at it.

Mine did same thing.. this may not be the entire issue but I can promise you it's likely part of it .

And yes you need a tune. Bad. I got mine done by willie at dirty racing. I also got a quarterhorse from em so I can tune it myself later. For the price it's a good buy to know you have it all at your fingertips anytime.
 
Reactions: STOCK94

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 7, 2017
#7
  • Jun 7, 2017
  • #7
I have a dyno tune scheduled for next Wednesday, between now and then I will move the IAT sensor and see how that helps. Thanks for the input fellas I will definitely update the results and anything else we find next week.
 

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 7, 2017
#8
  • Jun 7, 2017
  • #8
The
a91what said:
I have to agree, the issue I am imagining is the turn on the pipe for the intake to the SC.

How does the mass air mount? Is it in the piping or does the filter slam on the end.
Click to expand...
The mass air and filter are on the end of the 90deg tube that comes off the blower itself, so probably about 6 to 8 inches from the impeller.
 
R

RioRed95Cobra

Active Member
Apr 7, 2017
180
17
28
Jun 7, 2017
#9
  • Jun 7, 2017
  • #9
STOCK94 said:
The

The mass air and filter are on the end of the 90deg tube that comes off the blower itself, so probably about 6 to 8 inches from the impeller.
Click to expand...

Your MAF is only 8" from the impeller?? Do you have any pictures?
 

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 8, 2017
#10
  • Jun 8, 2017
  • #10
Tried moving IAT between blower and TB, no difference, still surging.
Guess we will have to wait till Wednesday for the tune.
 

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 8, 2017
#11
  • Jun 8, 2017
  • #11
This is the pic without intake discharge tube installed, mass air is at the end of the 90deg tube under fender.
 

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 8, 2017
#12
  • Jun 8, 2017
  • #12
RioRed95Cobra the engine sits behind the front wheels in this car so there is plenty of room to turn the tube straight out of the blower.
 
R

RioRed95Cobra

Active Member
Apr 7, 2017
180
17
28
Jun 8, 2017
#13
  • Jun 8, 2017
  • #13
Looks good.. is that enough room for the MAF to actually meter air/work??
 

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 8, 2017
#14
  • Jun 8, 2017
  • #14
Where it is located there is good air flow and a space of about 2x2 feet with an external duct from brake cooler duct coming in.
 
R

RioRed95Cobra

Active Member
Apr 7, 2017
180
17
28
Jun 8, 2017
#15
  • Jun 8, 2017
  • #15
STOCK94 said:
Where it is located there is good air flow and a space of about 2x2 feet with an external duct from brake cooler duct coming in.
Click to expand...

Yes airflow.. too much so i'm thinking.. those MAFs are very delicate.. and so much turbulence from the inlet sucking that much air that close to it could be throwing it waayyyyyyy off. Most people mount their MAF down in the fender away from the inlet so there is less turbulence and the MAF can meter air smoothly..

Just things i've noticed over my own build and all the same questions I went through.. vortech as well. Is your maf a draw thru or blow thru?
 
Reactions: STOCK94 and a91what

STOCK94

Member
Aug 15, 2004
34
0
6
Atlanta, Ga.
Jun 9, 2017
#16
  • Jun 9, 2017
  • #16
RioRed95Cobra said:
Yes airflow.. too much so i'm thinking.. those MAFs are very delicate.. and so much turbulence from the inlet sucking that much air that close to it could be throwing it waayyyyyyy off. Most people mount their MAF down in the fender away from the inlet so there is less turbulence and the MAF can meter air smoothly..

Just things i've noticed over my own build and all the same questions I went through.. vortech as well. Is your maf a draw thru or blow thru?
Click to expand...
That I'm unsure of, I know it is being drawn through right now.
 

revhead347

Apparently my ex-husband made that mistake.
20+ Year Stangneter
Jun 14, 2004
9,302
1,645
214
Acworth, GA
Jun 12, 2017
#17
  • Jun 12, 2017
  • #17
Don't bother wasting money tuning on the dryno with a Chinese MAF. Buy a Pro-M or SCT3000 meter before you go the Dyno.

Kurt
 

a91what

SendMeUrDataLog
10 Year Member
Apr 6, 2011
10,739
6,721
214
Hillsborough county
Jun 13, 2017
#18
  • Jun 13, 2017
  • #18
Hah I missed the part about it being granatelli..... that stuff is junk.
 
You must log in or register to reply here.

Similar threads

7
Engine Random hanging idle
  • 706 Saleen
  • Feb 11, 2026
  • Fox 5.0 Mustang Tech
Replies
9
Views
665
Fox 5.0 Mustang Tech Feb 19, 2026
86HO5.0
8
SURGING IDLE / NO IDLE CHECKLIST FOR 1996–1998 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
755
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
SURGING IDLE / NO IDLE CHECKLIST FOR 1999–2004 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
935
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
Fox dumping fuel at idle afr 10:1
  • Mattjhop23
  • Aug 5, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
33
Views
3K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Sep 3, 2024
Mattjhop23
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific 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?