Car is backfiring - Forums at Modded Mustangs
 
LinkBack Thread Tools
post #1 of 17 Old May 7th, 2009, 07:28 PM Thread Starter
Sheriff Metal Face
 
Chris951's Avatar
 
Join Date: Aug 2007
Location: Chandler, AZ
Posts: 5,579
       
iTrader: 0 reviews
Car is backfiring

So ever since I got my car it will backfire through the exhaust. It only does it on WOT runs when I'm shifting around 5k. Otherwise it won't do it if I keep the rpms down. But the past couple months now it has been backfiring through the intake when its cold. It will only do it once in a while though like once a week and when it happens it will only do it once maybe twice. I know I need to set my timing but could I be running lean or rich? I can't really tell myself because I have an o/r h-pipe and dumps so it always smells. I was thinking about getting an adjustible fpr. Would that help along with setting my timing?
Chris951 is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old May 7th, 2009, 10:14 PM
MM Fanatic
 
mxnate116's Avatar
 
Join Date: Jun 2007
Location: Spokane, WA
Posts: 3,357
         
iTrader: 1 reviews
depends on what your fuel pressure is now. if its high or low an adjustable could help, but so could a new stock one.

i put a new fpr on mine and it ran amazing for two weeks then slowly went back to shit(popping through the intake all the time). i need to check my fuel pressure again to see if it crapped out again.
mxnate116 is offline  
post #3 of 17 Old May 7th, 2009, 10:20 PM
!oznog.rd
 
dr.gonzo!'s Avatar
 
Join Date: Oct 2006
Location: OP KS
Posts: 21,612
Blog Entries: 1
                     
iTrader: 0 reviews
How long has it been since you had a tune up? Any exhaust leaks or loose header bolts?

Quote:
I'd rather have a bottle in front of me than a frontal lobotomy
dr.gonzo! is online now  
post #4 of 17 Old May 7th, 2009, 11:38 PM
Regular
 
Join Date: May 2008
Location: Alberta
Posts: 118
 
iTrader: 0 reviews
Subscribing here, i have same problem with my 87. You still runnin speed density system? Mine also backfires around 5k also when about to shift. I too have a off road x pipe, and have to real smelly exhaust and fuel smell. I bought plugs,rotor,cap,wires,k&n filter cleaner. Gonna tune up, sdjust timing, change oil, flush rad clean up my dirty k&n. Im hoping if i put on a short belt and eliminate the smog pump it will help with the exhaust smell.

1987 Mustang GT 5.0 5spd t-roofs, FRPP 4.10 gears, MM subframe connectors, FRPP a arms, Tokico Hp struts/shocks, alum rad, electric fan, dcc fan control unit, 6g alternator
Ntv69 is offline  
post #5 of 17 Old May 7th, 2009, 11:54 PM Thread Starter
Sheriff Metal Face
 
Chris951's Avatar
 
Join Date: Aug 2007
Location: Chandler, AZ
Posts: 5,579
       
iTrader: 0 reviews
Quote:
Originally Posted by dr.gonzo View Post
How long has it been since you had a tune up? Any exhaust leaks or loose header bolts?
Actually yeah, Both the bolts came out at one point on the #4 cylinder and I think the bolt holes in the head are warped because I cannot get new ones in.

And I did a tune up when I bought it in september. New plugs, cap and rotor, cleaned the TB and iac, etc. I've also seafoamed it like 3 times lol.

Last edited by Chris951; May 8th, 2009 at 12:06 AM.
Chris951 is offline  
post #6 of 17 Old May 7th, 2009, 11:56 PM
Newbie
 
Join Date: Jan 2007
Posts: 39
 
iTrader: 0 reviews
Quote:
Originally Posted by Chris951 View Post
So ever since I got my car it will backfire through the exhaust. It only does it on WOT runs when I'm shifting around 5k. Otherwise it won't do it if I keep the rpms down.
My car did the same thing after I installed my O/R H pipe until I removed my smog pump. Im not exactly sure why it made a difference (I have a few theories but Im not a mechanic so i can only guess) but as soon as i yanked the pump, put on a short belt and capped the smog stuff it quit backfiring...

Quote:
Originally Posted by JBIGBOOTSY View Post
Ditch the Brakes, they will only slow you down more.
Jackson is offline  
post #7 of 17 Old May 7th, 2009, 11:57 PM Thread Starter
Sheriff Metal Face
 
Chris951's Avatar
 
Join Date: Aug 2007
Location: Chandler, AZ
Posts: 5,579
       
iTrader: 0 reviews
Quote:
Originally Posted by Ntv69 View Post
Subscribing here, i have same problem with my 87. You still runnin speed density system? Mine also backfires around 5k also when about to shift. I too have a off road x pipe, and have to real smelly exhaust and fuel smell. I bought plugs,rotor,cap,wires,k&n filter cleaner. Gonna tune up, sdjust timing, change oil, flush rad clean up my dirty k&n. Im hoping if i put on a short belt and eliminate the smog pump it will help with the exhaust smell.
Yeah I'm still on SD. Sounds like we have a similar problem because mine backfires right in the middle of shifts at 5k.
Chris951 is offline  
post #8 of 17 Old May 7th, 2009, 11:58 PM Thread Starter
Sheriff Metal Face
 
Chris951's Avatar
 
Join Date: Aug 2007
Location: Chandler, AZ
Posts: 5,579
       
iTrader: 0 reviews
Quote:
Originally Posted by Jackson View Post
My car did the same thing after I installed my O/R H pipe until I removed my smog pump. Im not exactly sure why it made a difference (I have a few theories but Im not a mechanic so i can only guess) but as soon as i yanked the pump, put on a short belt and capped the smog stuff it quit backfiring...
I'm currently running a short belt. My smog pump seized a few months ago.
Chris951 is offline  
post #9 of 17 Old May 8th, 2009, 12:39 AM
Regular
 
Join Date: Mar 2009
Posts: 97
 
iTrader: 0 reviews
im getting backfriing over 4000 rpm. but im running an 85 carbed motor, with no exhaust on it ( open pipe after the car, its only temporary untill i can afford mufflers). Could it be a lean out backfire?
PolishSasquatch is offline  
post #10 of 17 Old May 8th, 2009, 12:43 AM
Regular
 
Join Date: May 2008
Location: Alberta
Posts: 118
 
iTrader: 0 reviews
Quote:
Originally Posted by Chris951 View Post
I'm currently running a short belt. My smog pump seized a few months ago.
What size belt? power steering? i assume no ac with the t-roofs

1987 Mustang GT 5.0 5spd t-roofs, FRPP 4.10 gears, MM subframe connectors, FRPP a arms, Tokico Hp struts/shocks, alum rad, electric fan, dcc fan control unit, 6g alternator

Last edited by Ntv69; May 8th, 2009 at 12:46 AM.
Ntv69 is offline  
post #11 of 17 Old May 8th, 2009, 12:56 AM Thread Starter
Sheriff Metal Face
 
Chris951's Avatar
 
Join Date: Aug 2007
Location: Chandler, AZ
Posts: 5,579
       
iTrader: 0 reviews
Quote:
Originally Posted by Ntv69 View Post
What size belt? power steering? i assume no ac with the t-roofs
83.5" belt. I have power steering and ac but the ac will be gone soon because it doesn't work
Chris951 is offline  
post #12 of 17 Old May 8th, 2009, 01:44 AM
Banned
 
Join Date: Aug 2008
Location: Phoenix,AZ
Posts: 3,014
   
iTrader: 1 reviews
Quote:
Originally Posted by Chris951 View Post
I know I need to set my timing but
hmmmmmmm......

PeteAndersonRacing.com
93mustank is offline  
post #13 of 17 Old May 8th, 2009, 10:57 AM
I Post Entirely Way Too Much
 
Join Date: Apr 2006
Location: Gatorland
Posts: 7,595
     
iTrader: 3 reviews
When my car pops through the intake it's due to lean conditions. Often low fuel pressure. It did it more often in the winter now. If you have an adjustable fpr make sure that once it's adjusted, that the nut is tight.

I had m y car tuned on 40psi or so. When back for a slight retune and it was going leaner and leaner. Turned out my fpr nut was loose and it was slowly dropping over the course of a month.

flattusmaximus78 is offline  
post #14 of 17 Old May 8th, 2009, 03:32 PM
Regular
 
Join Date: Apr 2007
Posts: 390
 
iTrader: 0 reviews
yes ther are AC on t-tops,
Also i had the same prob with the back fireing although it was a carbed engine.
this would only happen under load at 5K.
found out there was a very very very small crack in the boot of one of the plug wires, onced changes no problems any longer
hopper is offline  
post #15 of 17 Old May 8th, 2009, 06:05 PM Thread Starter
Sheriff Metal Face
 
Chris951's Avatar
 
Join Date: Aug 2007
Location: Chandler, AZ
Posts: 5,579
       
iTrader: 0 reviews
Quote:
Originally Posted by flattusmaximus78 View Post
When my car pops through the intake it's due to lean conditions. Often low fuel pressure. It did it more often in the winter now. If you have an adjustable fpr make sure that once it's adjusted, that the nut is tight.

I had m y car tuned on 40psi or so. When back for a slight retune and it was going leaner and leaner. Turned out my fpr nut was loose and it was slowly dropping over the course of a month.
I'm gonna get an adjustable fpr when i can get some money.
Chris951 is offline  
post #16 of 17 Old May 8th, 2009, 07:50 PM
Regular
 
Join Date: May 2008
Location: Alberta
Posts: 118
 
iTrader: 0 reviews
Does a kirban adj regulator attach right too stock fuel rails? Anyone runni a pressure gauge beside it??

1987 Mustang GT 5.0 5spd t-roofs, FRPP 4.10 gears, MM subframe connectors, FRPP a arms, Tokico Hp struts/shocks, alum rad, electric fan, dcc fan control unit, 6g alternator
Ntv69 is offline  
post #17 of 17 Old May 8th, 2009, 11:14 PM
I Post Entirely Way Too Much
 
Join Date: Apr 2006
Location: Gatorland
Posts: 7,595
     
iTrader: 3 reviews
kirban bolts right in on the rail. I put my guage on the rail were the shrader vavle went. I just put a nos fitting in.

flattusmaximus78 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Forums at Modded Mustangs forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome