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

What Octane Should I Run Before Heading To Dyno?

  • Thread starter Thread starter 90lxwhite
  • Start date Start date Oct 12, 2013

90lxwhite

I'm kind of a She-Man
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Oct 12, 2013
#1
  • Oct 12, 2013
  • #1
Does it matter? I usually run 93 but dunno if it helps, hurts, or indifferent.
 

Mustang5L5

That is…until I whipped out my Bissell
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Oct 12, 2013
#2
  • Oct 12, 2013
  • #2
Do you have a tune or any mods requiring higher octane?

Are you getting a tune?
 
Reactions: stykthyn

Bullitt347

I have been doing it wrong this whole time
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Oct 12, 2013
#3
  • Oct 12, 2013
  • #3
Run the fuel that you normally run, that way the dyno numbers are realistic and if any tuning is done it will be correct for the fuel you always run.
 
Reactions: Gearbanger 101, jrichker and A5literMan

84Ttop

They make new pistons every day, so why worry?
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Oct 12, 2013
#4
  • Oct 12, 2013
  • #4
Exactly! Use the same fuel you would always use!
 

90lxwhite

I'm kind of a She-Man
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Oct 12, 2013
#5
  • Oct 12, 2013
  • #5
Has been tuned when motor was fresh. But since then had intake and exhaust work but same heads. Reason for going back is to check a/f ratio. Hasn't been runnin to good lately. Smells rich, gassy ya know
 

jrichker

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#6
  • Oct 13, 2013
  • #6
90lxwhite said:
Has been tuned when motor was fresh. But since then had intake and exhaust work but same heads. Reason for going back is to check a/f ratio. Hasn't been runnin to good lately. Smells rich, gassy ya know
Click to expand...
Have you dumped the codes to make sure there isn't a sensor or wiring problem present?
 

90lxwhite

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Oct 14, 2013
#7
  • Oct 14, 2013
  • #7
jrichker said:
Have you dumped the codes to make sure there isn't a sensor or wiring problem present?
Click to expand...
Nah she's been on the back burner kinda. Busy w work and ad weather. The o2's aren't that old and neither is maf
 

f8tlfiveo

My wife likes my spool and blow-off valve.
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#8
  • Oct 14, 2013
  • #8
Buy a wideband setup.. They are only 150$-200$ on eBay for a aem or innovate. Then you can monitor it all the time
 

jrichker

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#9
  • Oct 14, 2013
  • #9
Going to the dyno tune without dumping and fixing the codes is a lot like going out the front door and leaving you pants hanging in the closet. You haven't done everything you need to do to be prepared to go.

There may be codes that will affect your tune. The turner will charge you $$$ to fix them so that your car can be properly tuned. It is possible that the problems you are having are code related and you can fix them much cheaper than a tuner will do it.


Dump the codes: Codes may be present even if the Check Engine Light (CEL) isn't on.

Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.

Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.





If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and driveablity problems

Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor, and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
See AutoZone Part Number: 25886 , $10




Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30-$36.
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
3,310
374
134
Between the Red and Rio
Oct 14, 2013
#10
  • Oct 14, 2013
  • #10
The place that tuned it last time put in an sct chip and they do "free" tunes after the 1st you just pay dyno time. But yeah guess I can dump codes w paper clip to see if there are any.
 

A5literMan

At least it is lumpy...
5 Year Member
Jul 30, 2011
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Oct 15, 2013
#11
  • Oct 15, 2013
  • #11
jrichker said:
Going to the dyno tune without dumping and fixing the codes is a lot like going out the front door and leaving you pants hanging in the closet. You haven't done everything you need to do to be prepared to go.

There may be codes that will affect your tune. The turner will charge you $$$ to fix them so that your car can be properly tuned. It is possible that the problems you are having are code related and you can fix them much cheaper than a tuner will do it.


Dump the codes: Codes may be present even if the Check Engine Light (CEL) isn't on.

Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.

Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.





If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and driveablity problems

Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor, and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
See AutoZone Part Number: 25886 , $10




Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30-$36.
Click to expand...
The Equis-digital code reader link isn't working FYI or it isn't with my iPhone.
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
3,310
374
134
Between the Red and Rio
Oct 15, 2013
#12
  • Oct 15, 2013
  • #12
A5literMan said:
The Equis-digital code reader link isn't working FYI or it isn't with my iPhone.
Click to expand...
Found one on summit
 

A5literMan

At least it is lumpy...
5 Year Member
Jul 30, 2011
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Oct 15, 2013
#13
  • Oct 15, 2013
  • #13
90lxwhite said:
Found one on summit
Click to expand...
Cool. Now I can order one. Thanks
 

jrichker

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Oct 15, 2013
#14
  • Oct 15, 2013
  • #14
A5literMan said:
The Equis-digital code reader link isn't working FYI or it isn't with my iPhone.
Click to expand...

www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW $22+shipping

Check WalMart -, they may have or order it for you, but they do have it listed. http://www.walmart.com/ip/Equus-Products-3145-Digital-Ford-Code-Reader-1982-1995/16606975 $25
 
Reactions: A5literMan

madspeed

Colonel Mustard
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Nov 29, 1999
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Oct 15, 2013
#15
  • Oct 15, 2013
  • #15
are you getting a dyno tune or just goingto see what she's got? Many tuners won't touch it if there's fault codes
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
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Oct 15, 2013
#16
  • Oct 15, 2013
  • #16
http://www.amazon.com/dp/B000EW0KHW/?tag=stangnet-20 Amazon always has them in stock
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
3,310
374
134
Between the Red and Rio
Oct 15, 2013
#17
  • Oct 15, 2013
  • #17
madspeed said:
are you getting a dyno tune or just goingto see what she's got? Many tuners won't touch it if there's fault codes
Click to expand...
A little of both??? well it had to get tuned after the rebuild awhile back just to get er running due to the cam. At that time it had old rusted out flowmasters due to sitting awhile prior to rebuild. It now has a lil intake and exhaust work so don't really know if it "needs" a time or if they could get anymore out if it w a tune but figurd since a new tune would be free minus dyno time might as well make an appointment and see what happens. But before I go I'm gonna see if it has any codes. Smells rich since the a/c was fixed. "Gassy"
 

A5literMan

At least it is lumpy...
5 Year Member
Jul 30, 2011
4,674
2,343
194
Illinois
Oct 15, 2013
#18
  • Oct 15, 2013
  • #18
jrichker said:
www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW $22+shipping

Check WalMart -, they may have or order it for you, but they do have it listed. http://www.walmart.com/ip/Equus-Products-3145-Digital-Ford-Code-Reader-1982-1995/16606975 $25
Click to expand...
Thank you. Mine just starting acting up with a surging/hanging idle so I'm going to run the codes. I'm pretty sure it's the TPS but will check first. Thanks again
 
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