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Engine Rough idle, hit gas, stumbles and stalls

  • Thread starter Thread starter Ironjack-5.0
  • Start date Start date May 21, 2021
I

Ironjack-5.0

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  • May 21, 2021
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93 fox, stock block. Gt40 3 bar heads, trick flow street intake, long tubes, x-pipe, b-cam. 19lb injectors. Timing set to 14 BTDC, new plugs. TPS at 0.97. Car starts and idles good, as soon as I tap the gas and the rpms go back down, car starts to surge and then dies. Starts right back up and does the same thing...I’ve seen multiple threads of very similar issues, just no resolutions. I appreciate the help.
 

General karthief

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#2
  • May 21, 2021
  • #2
Just put it together or recently miss behaving?
 
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Ironjack-5.0

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May 22, 2021
#3
  • May 22, 2021
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Just recently put it back together...intermittent stalling and stumbling idle has always been an issue.
 
I

Ironjack-5.0

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  • Jun 13, 2021
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Same issues…no change sine last post. Any ideas out there?
 

Potomus Pete

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  • Jun 13, 2021
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If you tried everything it could be the blue capacitors on the computer
 

Potomus Pete

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#6
  • Jun 13, 2021
  • #6
Fuel pressure, ignition module there is like ten culprits that need to be checked. Mine was never right till I got a throttle position sensor. After that all was pretty good. Then I got rebuilt four hole injectors, and now I have the new car ride. Lots of issues to go thru.
 

General karthief

wonder how much it would cost to ship you a pair
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Have you gone through the surging idle checklist?
 

jrichker

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Ironjack-5.0 said:
93 fox, stock block. Gt40 3 bar heads, trick flow street intake, long tubes, x-pipe, b-cam. 19lb injectors. Timing set to 14 BTDC, new plugs. TPS at 0.97. Car starts and idles good, as soon as I tap the gas and the rpms go back down, car starts to surge and then dies. Starts right back up and does the same thing...I’ve seen multiple threads of very similar issues, just no resolutions. I appreciate the help.
Click to expand...
You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix.

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 
Reactions: Potomus Pete and General karthief

Potomus Pete

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#9
  • Jun 14, 2021
  • #9
They are right IronJack. I went thru the list without skipping a step. While doing the list you might find other small issues. Early on I had to do the list as a fairly novice backyard mechanic. When your done you will feel like an expert as you get to know your car.
 
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