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

rich fuel smell

  • Thread starter Thread starter waxman
  • Start date Start date Jun 8, 2021
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jun 8, 2021
#1
  • Jun 8, 2021
  • #1
well i havent checked anything yet,but i am getting a rich fuel smell .i have an 88 lx and i dont know were the temp sensor for the ecm is. recently took the iac off,cleaned it out and replaced the gasket. has anyone had this happen? thanks
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,899
10,554
203
polk county florida
Jun 9, 2021
#2
  • Jun 9, 2021
  • #2
Are we talking raw fuel smell or rich exhaust?
 
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jun 10, 2021
#3
  • Jun 10, 2021
  • #3
rich fuel
 
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jun 10, 2021
#4
  • Jun 10, 2021
  • #4
o 2 sensor tip is white,and plugs too,ordered a ecm temp sensor, and air temp sensor and a map sensor
 

McFly2

Member
Nov 21, 2020
68
11
18
Cincinnati
Jun 10, 2021
#5
  • Jun 10, 2021
  • #5
waxman said:
rich fuel
Click to expand...
say whatt?
 

McFly2

Member
Nov 21, 2020
68
11
18
Cincinnati
Jun 10, 2021
#6
  • Jun 10, 2021
  • #6
How does it idle and run under load?
 
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jun 10, 2021
#7
  • Jun 10, 2021
  • #7
high idle lumbers some
 

McFly2

Member
Nov 21, 2020
68
11
18
Cincinnati
Jun 11, 2021
#8
  • Jun 11, 2021
  • #8
I would look to see if you have a vacuum leak. Or exhaust leak up stream from the o2 1 sensors. Exhaust leak at your exhaust manifold / exhaust pipe connection can be checked by putting hand up to that spot; to feel for leak at idle (while on lift if possible). Chock all 4 wheels if you have to climb under car.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,899
10,554
203
polk county florida
Jun 11, 2021
#9
  • Jun 11, 2021
  • #9
Not enough info to render a opinion on what to do.
I will say there is a 'surging idle checklist' in the tech, how to thread in the 'sticky' section at the top of the 5.0 tech forum, read and follow directions.
 
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jun 13, 2021
#10
  • Jun 13, 2021
  • #10
well i put a new act and ecm sensors in it. will drive to see if ok now. sprayed carb clnr to look for vac leak,none found.
 
Reactions: General karthief
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jun 20, 2021
#11
  • Jun 20, 2021
  • #11
new ford o2 sensor installed will drive soon to see results
 
Reactions: McFly2
J

junkyardwarrior

Well-Known Member
Jan 10, 2011
400
113
63
Jun 21, 2021
#12
  • Jun 21, 2021
  • #12
You simply cannot go by "rich smell"-period.

The ONLY way you are ever gonna know if it's truly rich or lean is O2 sensor feedback. This, meaning you're gonna have to look at either fuel trims (OBD2) or KAMRF (obd1) and I doubt you have the capability to look at either one, thus the best option in that case is to pull the codes and see what you have. You should have at least one code. Just because you ain't got a check engine light on (or don't have a working light at all), doesn't mean that there arent codes stored. Dump the codes and see what she wants, go from there.

vacuum leaks. Carb cleaner trick only works if you have a big leak. A small leak, carb cleaner won't pick it up and the engine idle won't change. Secondly the O2 will read the rich mixture that the carb cleaner is forcing, and the eec will trim the fuel accordingly. Thirdly if you have a small leak and the leak picks up carb cleaner, the idle will start to rise or drop, the EEC will detect it (and O2 sensor change) in milliseconds, and will pull the idle back to where it wants to see it, thus the carb cleaner trick does not work. You have to use a smoke machine OR you can pressurize the intake via a home-made "boost leak tester" (google it). Do not exceed 10 psi if you do this. With a little pressure in the intake you can then spray some soapy water around all of the vacuum controlled components, intake system, throttle body, iac, tps, etc....a leak will show up. Smoke machine is the best option as it is very low pressure and very very easy to spot any leaks.
 
Reactions: General karthief
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Jul 29, 2021
#13
  • Jul 29, 2021
  • #13
well i replaced both temp sensors,o 2 sensor,cleaned the plugs.so the smell is gone and i think i m getting mpg now. guess old sensors were set in their ways. will finish mpg later.runs great for now.
 
W

waxman

20+ Year Stangneter
Aug 6, 2004
49
7
18
central il
Aug 2, 2021
#14
  • Aug 2, 2021
  • #14
well i checked the mileage after i filled up. with the new sensors that i added,mpg went from 20 to 26. pretty good i thought,
 
You must log in or register to reply here.

Similar threads

0
'04 V6 running rich excessively on both banks
  • 04DSGVert
  • Oct 26, 2025
  • SN95 V6 Mustang Tech
Replies
2
Views
343
SN95 V6 Mustang Tech Oct 27, 2025
04DSGVert
0
S
Fuel ‘88 GT Runs Rich Cold — Fixes Itself When I Unplug Sensors (ECT, MAF, O2, etc.)
  • Sufarry
  • Nov 6, 2025
  • Fox 5.0 Mustang Tech
Replies
12
Views
809
Fox 5.0 Mustang Tech Nov 9, 2025
Mustang5L5
How do we feel about first gen fuel caps?
  • Teen'93stang5.0
  • Apr 25, 2026
  • Mustang Sound & Shine All
Replies
4
Views
345
Mustang Sound & Shine All May 3, 2026
General karthief
2
Running very very rich
  • 2esoteric
  • Oct 31, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
333
Fox 5.0 Mustang Tech Oct 31, 2025
Noobz347
M
01 mustang 3.8 fuel pressure issue
  • Mhaley2006
  • May 29, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
114
1996 - 2004 SN95 Mustang -General/Talk- May 29, 2026
Mhaley2006
M
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2.3L (N/A & Turbo) 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?