Occasional rough idle and dying - Ford Mustang Forum
Like Tree3Likes
  • 1 Post By Travis98146
  • 2 Post By JBert
 
LinkBack Thread Tools
post #1 of 14 (permalink) Old 04-10-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
Occasional rough idle and dying

Hey guys, first post here, so my car is starting to have this issue occasionally. On cold starts it will have a really rough idle and if I give it gas it will die. If I try to drive it, it will die as well. The issue goes away after a few minutes, and happens about once a week. Mods are CJ intake manifold, gt500 throttle body, jba catless longtubes, jba catless h pipe with resonator delete, and gt500 axle backs.
https://youtu.be/8_VCBI7qgtc

RowdyCoyote is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 04-10-2019
PONY Member
 
Travis98146's Avatar
 
Joined: Jun 2016
Location: Seattle
Posts: 932
 
Garage
It sounds like you may have a little water in the fuel tank that's being run through the system. Once the engine heats up a little this moisture isn't enough to cause a misfire. You might also check (or have checked) your fuel pressure as your fuel pump/pressure regulator might be getting tired and letting fuel leak back.

5.0 Coyote likes this.
Travis98146 is offline  
post #3 of 14 (permalink) Old 04-10-2019
SHELBY GT 350 Member
4.6L Member
S197 Member
 
JBert's Avatar
 
Joined: Jan 2011
Location: Central Massachusetts
Posts: 8,956
           
did this issue show itself after some modification or change; if so, what was that modification or change?

or has it just developed over time with no changes to the car during that time?

| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day
JBert is offline  
 
post #4 of 14 (permalink) Old 04-10-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
So I actually just bought the car about a week ago, and this is the only thing wrong with it.
RowdyCoyote is offline  
post #5 of 14 (permalink) Old 04-10-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
Is there a way to check for water in the fuel or will I just have to drain the tank? It never throws a cel either. But when it dies while driving the powertrain light will come on.
RowdyCoyote is offline  
post #6 of 14 (permalink) Old 04-10-2019
SHELBY GT 350 Member
4.6L Member
S197 Member
 
JBert's Avatar
 
Joined: Jan 2011
Location: Central Massachusetts
Posts: 8,956
           
I think there are fuel additives that will take care of the water, if that is the issue -- check local car parts store?

also I think but not sure -- if there is ethanol in the gas, that will effectively trap the water . . . do you use ethanol-free gas? might be worth a try to simply add some fresh gase with ethanol

disclaimer: I am not sure about the above so don't take my word for it!

since the car is new to you, this could have been an existing problem . . . the modifications on the car do require a good tune to go with them, and often the tune is the source of the problem . . . do you know anything about the tune that is loaded?

| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day
JBert is offline  
post #7 of 14 (permalink) Old 04-10-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
No, I dont use ethanol free gas. I thought bad gas may have been the problem when I got it, so I filled it up from a different station and nothing changed. The car is tuned by vmp so I wouldn't think it is a tuning issue.
RowdyCoyote is offline  
post #8 of 14 (permalink) Old 04-10-2019
SHELBY GT 350 Member
4.6L Member
S197 Member
 
JBert's Avatar
 
Joined: Jan 2011
Location: Central Massachusetts
Posts: 8,956
           
if VMP will talk to you, they might have some clues so it might be worth the phone call

| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day
JBert is offline  
post #9 of 14 (permalink) Old 04-10-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
I called them on Monday, and they said they would be more than happy to help. If I paid them $100
RowdyCoyote is offline  
SHELBY GT 350 Member
4.6L Member
S197 Member
 
JBert's Avatar
 
Joined: Jan 2011
Location: Central Massachusetts
Posts: 8,956
           
Quote:
Originally Posted by RowdyCoyote View Post
they said they would be more than happy to help. If I paid them $100

sounds like a bargain to me
5.0 Coyote and my89foxbody like this.

| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day
JBert is offline  
post #11 of 14 (permalink) Old 04-11-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
Where is the fuel pressure regulator located on these cars, and where do I check fuel pressure from. I just called vmp and they said i would have to buy a whole new tune for $300. So i would prefer to try and figure it out without doing that lol.
RowdyCoyote is offline  
post #12 of 14 (permalink) Old 04-13-2019 Thread Starter
Rookie
 
RowdyCoyote's Avatar
 
Joined: Apr 2019
Posts: 13
 
I also treated the fuel with no change.
RowdyCoyote is offline  
SHELBY GT 350 Member
4.6L Member
S197 Member
 
JBert's Avatar
 
Joined: Jan 2011
Location: Central Massachusetts
Posts: 8,956
           
hmmmm . . . it sounds like the fuel might not be the problem; but one way to make sure is to burn that whole tank of gas and then replace with fresh, "known good" gas (hopefully that would get rid of any water and you wouldn't have to actually drain the tank but not sure)

I am not sure about the fuel pressure regulator but my guess is that it is integrated in the fuel pump, which is in the tank; accessible under the back seat

I have a feeling this is tune and/or modifications related, since you do have some mods that require tune adjustment and it only happens when the engine is cold . . . best guess on how to address that would be to work with a tuner who will have you datalog the car and then check to see what is going on and fix it . . . VMP might be able to do that, or "Lito" ([email protected])

| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day
JBert is offline  
Rookie
 
cartersta@'s Avatar
 
Joined: Oct 2018
Posts: 27
 
Take the cai off, reinstall, replug the sensor, how do I know, mine did this today, after I took off the sensor, it was a leak at the throttle body, take battery cables off, take cai off, make sure that they are tight, reinstall, if that doesn't work, go see a certified friend with a computer
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum 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, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










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



Similar Threads
Thread Thread Starter Forum Replies Last Post
Surging Idle, dies when idling and when stopping Screaming04Gt 4.6L Talk 13 01-23-2017 12:25 PM
01 GT Runs Rich and Wont Hold Idle Ashlander 4.6L Tech 15 11-05-2016 04:11 PM
2000 mustang gt low idle when in gear mustang87will 4.6L Tech 1 07-22-2010 02:06 AM
1992 Mustang 2.3 Rough Idle Issues rickiiimac 2.3L Tech 1 06-15-2010 10:22 AM
Strange tremor when idle JaK1216 2005-2010 V6 Mustang Tech 9 01-10-2010 09:09 PM

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 Off
Pingbacks are Off
Refbacks are On

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


Search Engine Friendly URLs by vBSEO 3.6.1