• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

cold start backfiring issues

  • Thread starter Thread starter bdub
  • Start date Start date Mar 20, 2008
B

bdub

New Member
Sep 21, 2007
67
0
0
kinston
Mar 20, 2008
#1
  • Mar 20, 2008
  • #1
well i have a problem that only happens on a cold start, and only sometimes i notice it, the car will turn over and crank then idle, but unless you give it some gas it will cut off, ive replaced the IAC vavle, cleaned the mass air, cleaned the throttle body. the main problem im concerned with is that on the cold start the car will backfire and make a loud pop through the intake, but as soon as the car warms up some it will wont do it again until the next cold start? any ideas?
 

myslo50

Member
Jun 12, 2006
247
3
18
ohio
Mar 20, 2008
#2
  • Mar 20, 2008
  • #2
try adjusting your throttle plate and timing ,to start with
 
B

bdub

New Member
Sep 21, 2007
67
0
0
kinston
Mar 21, 2008
#3
  • Mar 21, 2008
  • #3
adjusted throttle already, havent checked the timing yet, its kinda got me stumped
 

cenok is family

15 Year Member
Jun 25, 2003
1,409
69
79
Norman, Ok
Mar 21, 2008
#4
  • Mar 21, 2008
  • #4
next, try providing more pics of the girls in your avatar and then go from there.


where'd you get the IAC? about 98% of the parts store IAC's i've ever used either crapped out after a few months or just sucked from the get-go. for example: i had some idling issues, so i got a new IAC from Oreilly's. my problem cleared up a little bit, but the surge was still there. after about 2 months, it gradually got worse again, even to the point where the car would stall under decelleration. i ended up taking the IAC back off, cleaning out my ORIGINAL 20 year old ford IAC with carb cleaner and putting it back on. cured all my problems. during cold starts, the eec almost completely looks to the ACT and ECT sensors to determine the amount of fuel needed and the IAC is opened 100%. once the car starts and your key springs back to the "run" position, timing is also determined by the ACT and ECT. if the IAC isn't opening up, that'll definitely cause your stall. if either your ACT and/or your ECT sensors are bad, the eec would fuel map incorrectly (due to the inaccurate coolant and air temp readings) and could be dumping too much fuel for start up which could (and is probably) causing that backfire. hope this helps some.
 
B

bdub

New Member
Sep 21, 2007
67
0
0
kinston
Mar 21, 2008
#5
  • Mar 21, 2008
  • #5
yeah i will have to try getting another iac, thing is, the day i put the new one on, it was still doing the same thing, could have just been a defective one
 
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
422
Fox 5.0 Mustang Tech Feb 19, 2026
86HO5.0
8
1
Engine 91 mustang 302 Low acceleration car backfires pops and acts like it doesn’t want to take fuel
  • 1991Fox5.0
  • Oct 4, 2025
  • Fox 5.0 Mustang Tech
Replies
16
Views
927
Fox 5.0 Mustang Tech Oct 6, 2025
1991Fox5.0
1
Hard to start when engine is cold
  • 86_Capri
  • Mar 11, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
31
Views
747
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Mar 21, 2026
86_Capri
F
1986 mustang no start
  • foxyjamss221
  • Oct 11, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
4
Views
291
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 13, 2025
foxyjamss221
F
A
Rough idle - cylinder 1 and 6 misfire HELP
  • austindavies935
  • Jul 24, 2025
  • SN95 4.6L Mustang Tech
Replies
12
Views
632
SN95 4.6L Mustang Tech Jul 24, 2025
gkomo
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 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?