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Engine Missing or running rough

  • Thread starter Thread starter hollywoodjmack
  • Start date Start date Jul 20, 2022
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hollywoodjmack

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Jul 20, 2022
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Hollywood Alabama
Jul 20, 2022
#1
  • Jul 20, 2022
  • #1
I have a 92 mustang with a 5.0 that's running really rough and not much power. I'm confused as what to try next on it. It has a B cam, 24# injectors, eldebrock upper n lower intake, but bottom end is stock. I've owned the car for close to 20 years and it sits alot. I have put new plugs. Wires, distributor cap, rotor button, new coil, n new iac. I done a base idle reset, and I checked fuel pressure and it's at 35 psi. I bought a code reader and it gave an egr code but when I try to do the test with it running it almost instantly dies. I tried idling it up, but it still dies when I try to do the test. Sorry for the long text, but I'm hoping someone has ran into this before and can point me in the right direction
 
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Pinellas50

Active Member
Aug 5, 2020
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Tampa Bay, FL
Jul 21, 2022
#2
  • Jul 21, 2022
  • #2
Is this something that started happening on its own or after something was done to the car?

Does it sound like there is a consistent miss while running as if one of the cylinders isn't making power?

I would start by pulling the plugs to see what they look like. Check for any vacuum leaks as well.
 
Reactions: General karthief
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hollywoodjmack

New Member
Jul 20, 2022
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Hollywood Alabama
Jul 21, 2022
#3
  • Jul 21, 2022
  • #3
Pinellas50 said:
Is this something that started happening on its own or after something was done to the car?

Does it sound like there is a consistent miss while running as if one of the cylinders isn't making power?

I would start by pulling the plugs to see what they look like. Check for any vacuum leaks as welth
Click to expand...
 
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hollywoodjmack

New Member
Jul 20, 2022
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Hollywood Alabama
Jul 21, 2022
#4
  • Jul 21, 2022
  • #4
Thank you for your reply. No I haven't done anything to the car as far as mods or anything. It does sit alot and just started running weird one day. I pulled the plugs and they seemed wet n black in color. I'm building a smoke machine n will check for vacuum leaks soon
 

KRUISR

10 Year Member
Apr 16, 2015
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Jul 21, 2022
#5
  • Jul 21, 2022
  • #5
What process did you do for the base idle reset? Did you unplug both the IAC and spout connector when setting initial idle?
 
P

Pinellas50

Active Member
Aug 5, 2020
73
29
28
Tampa Bay, FL
Jul 21, 2022
#6
  • Jul 21, 2022
  • #6
Have you pulled the codes from the computer? That might help you zero in on the issue.
 
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hollywoodjmack

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Jul 20, 2022
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Hollywood Alabama
Jul 22, 2022
#7
  • Jul 22, 2022
  • #7
I did not pull the spout when doing the bas idle reset, I thought that was for setting the timing only. I did unplug the iac. Turned off accessories ran 2 minutes turned off for 2 minutes then turned on accessories n ran it for 2 minutes.

codes showed an egr code while not running the engine, but trying to pull codes while the engine is running shuts the motor off almost immediatly
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,983
10,611
213
polk county florida
Jul 22, 2022
#8
  • Jul 22, 2022
  • #8
Start by resetting the computer, pull off the negative cable for 20-30 minutes, attach the cable and drive it around for a while then check for codes.

Mustang TPS Adjustment - 0.999999v not necessary

EDIT: This post applies to 86-93 5.0 Mustangs. Seems to be a common myth, so lets sticky a thread explaining how the TPS works. Jrichker has provided the basic TPS guideline to follow. I'll just preference it with this. Adjusting your TPS to .99999999 volts is not necessary at all. There...
www.stangnet.com
 
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