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

Progress Thread finally tuning (and more)

  • Thread starter Thread starter JD1964
  • Start date Start date Apr 1, 2026
Prev
  • 1
  • …
  • 16
  • 17
  • 18
  • 19
Next
First Prev 18 of 19 Next Last

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 8:49 AM
#341
  • Yesterday at 8:49 AM
  • #341
Thank you Noobz for the analysis of the logs. My initial response;

1. I'll keep the current NA tune unchanged pending any discovery of the fuel trim imbalance.

2. Wideband gauge in car and value displayed on log screen are not identical but average a difference of about .1 with the gauge in the car reading .1 richer. The gauge and the log parameter are both set for gas.

3. O2's were replaced as a new pair in 2014 and approximately 20k miles ago. Bosch 13942 is the part number.

4. I will check O2 wiring for any concerns and correct if needed.

5. I will check for exhaust leaks at the noted locations and correct if needed. (none known at the time of this writing)

6. I will check for vacuum leaks and correct if needed. (none known at the time of this writing)

7. I will check ignition components and spark plugs. I'll photograph plug coloration and post pictures. Plugs are new 3923's

8. I will monitor the bank difference for any future changes and compare to existing log data.

9. If I dont find any intake or exhaust leaks, the first thing I might do is swap the O2's side to side and see if the imbalance follows.

10. If all else does not identify a condition that would explain the imbalance, I will send the injectors out for servicing.

One question at this point. Is it possible that the combo under this new tune needs some additional time to settle in where it may report more balanced fuel trims after adequate time?

Thanks, John D
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 11:23 AM
#342
  • Yesterday at 11:23 AM
  • #342
Here’s pictures of plugs. They are Autolite 3924’s. Pencil marks indicate location. Maybe 100 miles on these







 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 12:43 PM
#343
  • Yesterday at 12:43 PM
  • #343
Bosch 942. I’m going to swap sides when I put them back in. The wiring and connectors look good.

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,478
21,656
234
Box behind Walmart
Yesterday at 12:44 PM
#344
  • Yesterday at 12:44 PM
  • #344
The switching of the two sensors compared to the wideband looked very good too.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 1:24 PM
#345
  • Yesterday at 1:24 PM
  • #345
I see or hear nothing suspect of vacuum leaks. No exhaust leaks anywhere upstream of the O2's. No dry rotted or cut hoses and all vacuum connections clamped where necessary and others tight. PCV valve to its new grommet in the intake were sealed in there with RTV when I put intake back on last time. Obviously these are new intake gaskets with the recent head swap. New Remflex header gaskets.

The base of the spark plug thread body (part that is exposed in the combustion chamber) of plug #2 is darker than all the others. Heres #2 compared to #5. The rest of the plugs look mostly like #5. Maybe something is up with #2 injector? If it were dumping more gas than the others, would that explain the ECU working to pull gas from passenger side?

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,478
21,656
234
Box behind Walmart
Yesterday at 1:28 PM
#346
  • Yesterday at 1:28 PM
  • #346
It is possible but I have no way to tell.

The plug on the right does look a bit 'sooty'. Do you have any oil sitting in the intake behind the throttle body?
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 2:00 PM
#347
  • Yesterday at 2:00 PM
  • #347
Noobz347 said:
It is possible but I have no way to tell.

The plug on the right does look a bit 'sooty'. Do you have any oil sitting in the intake behind the throttle body?
Click to expand...
no oil on the intake under/behind TB
 
Reactions: Noobz347

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 2:06 PM
#348
  • Yesterday at 2:06 PM
  • #348
Well, before I get some more logs with O2's swapped sides I'm going to take care of another minor issue since I already have it on stands. I have a small pesky coolant leek from the drivers side most forward lower head stud. I need to drain the block, pull that stud, clean up those threads and redo the thread sealer. That is the only one leaking and luckily its one thats easy to get to
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 2:24 PM
#349
  • Yesterday at 2:24 PM
  • #349
Im going to swap position of plugs 2 and 5. That way I have a cleaner one where the dirtier one was. See what happens when I inspect them next time.
 
Reactions: Noobz347

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,478
21,656
234
Box behind Walmart
Yesterday at 3:06 PM
#350
  • Yesterday at 3:06 PM
  • #350
Once you get a data log in the new config, if nothing changes, you might try swapping that injector with one from the opposite bank.

Don't want to make too many changes at once.
 
Reactions: JD1964

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Yesterday at 5:08 PM
#351
  • Yesterday at 5:08 PM
  • #351
Noobz347 said:
Once you get a data log in the new config, if nothing changes, you might try swapping that injector with one from the opposite bank.

Don't want to make too many changes at once.
Click to expand...
If I get to the point I pull the upper and pull the fuel rail, all the injectors are going in for service. Let’s see what the O2 swap shows and then go to whatever the next step will be. I finished resealing the leaking head stud a little while ago.
 
Reactions: Noobz347

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,478
21,656
234
Box behind Walmart
Yesterday at 5:46 PM
#352
  • Yesterday at 5:46 PM
  • #352
JD1964 said:
If I get to the point I pull the upper and pull the fuel rail, all the injectors are going in for service. Let’s see what the O2 swap shows and then go to whatever the next step will be. I finished resealing the leaking head stud a little while ago.
Click to expand...

I think that is an excellent idea. One less thing to wonder about.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Today at 7:56 AM
#353
  • Today at 7:56 AM
  • #353
The tuning process needs to pause. Here’ why.

Upon fixing the minor leak from the drivers side lower front head stud, I was doing the final torquing of the nut. Snap on click type wrench set to 80 ft/lbs. I heard a click as I was cranking but it didn’t sound like the wrench clicking. I thought, “oh ”. I tried to pretend I didn’t hear it and went in for dinner. After dinner I went out and upon further examination I concluded the reality. The threads pulled.

So, it looks like next on the list is to pull the head and repair the threads with a Time Sert.

Wish me luck and toss any advice at me if you choose
 
Reactions: gkomo

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Today at 8:49 AM
#354
  • Today at 8:49 AM
  • #354
And by the way, since I’m pulling the intake to remove the head, the injectors are going in for service
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Today at 11:44 AM
#355
  • Today at 11:44 AM
  • #355
On the pull thread repair. I’ve seen discussions online about using 1/2” 351 head bolts in the 302 block with various people claiming lasting success. Considering I have AFR heads with holes sized for 1/2” bolts, is it a viable option to drill and tap for use of a 351 bolt in that one location? Of coarse, I would stick with 302 torque specs. Or, is the Time Sert my only real viable option?

In reality, the Time Sert option calls for drilling the initial hole larger than would be needed for the 1/2” bolt. Thus, if done successfully the 1/2” head bolt option would leave more block material in place.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Today at 1:49 PM
#356
  • Today at 1:49 PM
  • #356
Here we go. 1/2”x13 coarse x 2 1/2” grade 8. Exact dimensions of the 351 bolt for that location. The AFR head is already sized for this. The hole required for the 1/2”x13 tap is smaller than would be needed for the Time Sert option. I can easily try this bolt and do the work without removing the head. I will need to remove the header in order to get the bolt in and have clearance for torquing. If I mess this up there’s still another chance by pulling the head and using Time Sert. I’m drilling and tapping for this bolt for my first attempt at solution.

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,478
21,656
234
Box behind Walmart
Today at 1:59 PM
#357
  • Today at 1:59 PM
  • #357
Question: What do you torque this bolt to in comparison with the others?
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Today at 2:02 PM
#358
  • Today at 2:02 PM
  • #358
I’m taking it to 70 ft lbs which would be the stock tq for stock 302 bolts.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,574
1,602
194
Maryland
Today at 2:03 PM
#359
  • Today at 2:03 PM
  • #359
Thread sealer on the threads and a oil on the head to bolt washer surface
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,478
21,656
234
Box behind Walmart
Today at 2:05 PM
#360
  • Today at 2:05 PM
  • #360
I'm just gonna toss this out there because I don't know how critical is is for aluminum heads but...

Those bolts are torque to yield and two different diameter bolts torqued to the same spec, are not even.
 
Prev
  • 1
  • …
  • 16
  • 17
  • 18
  • 19
Next
First Prev 18 of 19 Next Last
You must log in or register to reply here.

Similar threads

Engine Felpro 9333 pt1 (with 8psi boost)
  • JD1964
  • Jan 14, 2026
  • Fox 5.0 Mustang Tech
Replies
18
Views
939
Fox 5.0 Mustang Tech Feb 1, 2026
Qtrhrse23
B
2001 SVT Cobra Overheating Issue
  • bradencaron0
  • May 8, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
255
1996 - 2004 SN95 Mustang -General/Talk- May 8, 2025
Noobz347
6
Hey all,I’m putting together a 302 for my 1968 Mustang and wanted to post the combo + some questions to make sure I’m not missing crucial
  • 68_Disgustang
  • Feb 22, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
5
Views
1K
1965 - 1973 Classic Mustangs -General/Talk- Monday at 2:12 PM
mattcrp1
M
SN95 Desktop 363 Engine Combination - Looking for input
  • WhiteCobra95
  • Sep 8, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
11
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 6, 2025
Habu135
A
95 Gt intermittent backfire
  • A_A_Ron
  • May 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
0
Views
476
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 26, 2025
A_A_Ron
A
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?