• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Engine This guy needs the help of this forum

  • Thread starter Thread starter Mcmahst
  • Start date Start date Jan 9, 2024
Prev
  • 1
  • 2
  • 3
  • 4
  • 5
Next
First Prev 4 of 5 Next Last

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Jan 23, 2024
#61
  • Jan 23, 2024
  • #61
Retainer wall around the base of the spring too. Will need to pull a VC to see




From what I know about them, they are probably on par with E7 heads in stock untouched form. Smallish valves, but higher compression. None of the crate motors came with these. Any chance this is an original engine with a EFI setup slapped on top?
 

limp

wrap a little cheese around it and its a done
5 Year Member
Oct 4, 2020
5,467
2,901
173
Florida
Jan 23, 2024
#62
  • Jan 23, 2024
  • #62
AeroCoupe said:
My dad and late uncle both had cars with 289 HiPo's so I heard all about them growing up and how Holman & Moody were the shop to send them to get worked over.

Also, it's possible the motor is not a crate motor rather a rebuild and they used crate to make it sound better.
Click to expand...
The good ole days........
There was a Payless store near my home in 70.. They had a really nice auto repair shop and sponsored two of the guys working there, who ran a 70 hemi Challenger in our local Super Stock ( I think) class at Balboa Drag strip in Eugene, Or.....
I was 15, itching to get my drivers license when I hung around there... One day a shipping truck backed up and I happened to be there when a large crate came out that said Keith Black on it. Their engine had come back after being tweaked at Keith Blacks shop....
Magical times back then for a dumb kid when the only car stuff was the monthly ' Hot Rod" magazine in the mail....
 
Reactions: Mcmahst

b_arrington

Member
Jan 18, 2024
28
6
13
Long Island, NY
Jan 23, 2024
#63
  • Jan 23, 2024
  • #63
Mustang5L5 said:
Retainer wall around the base of the spring too. Will need to pull a VC to see




From what I know about them, they are probably on par with E7 heads in stock untouched form. Smallish valves, but higher compression. None of the crate motors came with these. Any chance this is an original engine with a EFI setup slapped on top?
Click to expand...
Been thinking about that. Anything is possible with this car. Although it originally had an inline 6 so it would have needed a donor engine anyway.
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,896
4,020
183
Claremore, OK
Jan 23, 2024
#64
  • Jan 23, 2024
  • #64
The 289 HiPo heads are decent heads and will run well with a good intake. Another way to tell is to pull a valve cover is like Mike suggested. Also, all 289 HiPo heads have screw in rocker arm studs.
 
Reactions: b_arrington
5

5.0-5MT

Member
Dec 3, 2023
46
13
18
Seattle WA
Jan 24, 2024
#65
  • Jan 24, 2024
  • #65
b_arrington said:
His mom has always loved Mustangs and after she introduced him to BaT he fell in love with the classic Mustang. She totally drove him getting this car.
Click to expand...
I'm also 17 and my mom is the exact opposite. I think she believes it's too fast lol. My dad had an f150 with a coyote 5.0 in it and she was thinking they were the same motor, thought that it had too much power. She will be right when we finish building it good luck on your issues. I think i may be able to decipher why your son is getting such bad gas mileage lol.
 

b_arrington

Member
Jan 18, 2024
28
6
13
Long Island, NY
Jan 26, 2024
#66
  • Jan 26, 2024
  • #66
This weekend we’re going f to try to tackle the ACT sensor fault. We replaced the ACT and code 54 persist. Plan is to first confirm the signals are getting through the 10 pin connector so e need to do some voltage teats using a back pin method.

Questions
  • Pin 6 is the ACT sensor. Is that viewooked at the male, sensor side of the harness or the female/computer side? Diagram unclear.
  • I assume we need the check the voltage across the ACT pin no 6 and the signal return pin 1. Or do we need the ref voltage pin 2?
If we see good voltage we’ll move on to testing pins at the ECU.
 

b_arrington

Member
Jan 18, 2024
28
6
13
Long Island, NY
Jan 27, 2024
#67
  • Jan 27, 2024
  • #67
We did some testing at the white 10 pin connector to troubleshoot the code 54 and can’t figure out which pin is for the ACT. I know the diagram says it should be pin 6, but neither the voltage nor the wire colors are matching up to the color coded wiring harness diagrams . Here’s what we got.

At ACT sensor connector:
  • ~3v.
  • Wire colors: red and grey/yellow
At 10 pin connector, engine side, male pins. KOEO voltage across pin no 1 (volt-ret).
  • 2: 5v. Grey/yellow
  • 3: 0.47v. Purple/green
  • 4: 0.0v. Green
  • 5: 0.77v. Grey/white
  • 6: 4.59v. Green/purple
  • 7: variable 0-4.5v fluctuating. White/red
  • 8: 0.04v. Red/white
  • 9: 8.65v. Orange.
Any thoughts or suggestions appreciated.



 

Mcmahst

5 Year Member
Jan 19, 2021
681
267
83
Laguna Woods CA, fort Mohave AZ
Jan 28, 2024
#68
  • Jan 28, 2024
  • #68
Were you able to verify the pin 2 wire was in fact the ACT wire? Since they are both the same color. I ask because, if it can be verified that is correct, it might aid in finding the wiring diagram. On my car, the ACT wire is Light Green/Purple stripe.
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,896
4,020
183
Claremore, OK
Jan 28, 2024
#69
  • Jan 28, 2024
  • #69
Pulled my 1993 wiring diagrams out and snapped a couple pictures for you. This one shows the ACT sensor and the wiring going into the ten pin connector:



This one is just zoomed in on the ten pin connectors:

 
Reactions: b_arrington and General karthief

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Jan 29, 2024
#70
  • Jan 29, 2024
  • #70
I wonder if you have a different injector harness from another vehicle. The ACT wire color should be Light Green/Purple. The Ford trucks used a Yellow/Red wire. For the most part they are not interchangable as the trucks are batch fire, and Mustang is sequential. The injectors are not wired properly, and this might be the reason why your fuel economy is so poor. The injectors are not firing properly.

So this is worth exploring. Not saying this is definitely the case but should be investigated to make sure your harness is correct.

This doc is a bit older but you can see that the wire colors for pin 25 differ based on use. Mustang should be LG/P. This may also be helpful for the voltage/resistance chart

 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Jan 29, 2024
#71
  • Jan 29, 2024
  • #71
Pinout for the 10-pins. I would verify the injectors are pinned properly.

Red is your 12V+ on all the injectors. Center pin on the black connector. So just ring out all your other injectors to the location on the engine. For instance Pin 2. Ignore the wire color and just go to injector 2 (2nd one back pass side) and test continuity from the non-red wire to pin 2 on the 10pin and see if you have it. Try this for all the injectors you can reach without pulling the intake and see if they match up.

Ignore the wire color and just test pin 6 from the white connector out to the ACT plug and verify the wire is intact and you have it.

 
Reactions: General karthief and b_arrington

b_arrington

Member
Jan 18, 2024
28
6
13
Long Island, NY
Jan 29, 2024
#72
  • Jan 29, 2024
  • #72
This is so confusing and frustrating. So many different documents and first hand reports of different colors for the same connector. Some diagrams say ACT signal should be Green/Pink. Others say gray. Some guys say theirs is green/purple. None seem to be matching up with what I'm actually seeing. Pin 6 on mine is green/purple, but the two wires at the ACT itself are grey/yellow and red. The back pin tests at the 10 pin connector are not at all conclusive. Its enough to drive a guy to drink. Maybe it is actually the wrong harness? No idea; it's possible with the other stuff we've seen on the engine.

I know there's a ton of expertise here and I thank the folks here that have been patient and helpful.
 

b_arrington

Member
Jan 18, 2024
28
6
13
Long Island, NY
Jan 29, 2024
#73
  • Jan 29, 2024
  • #73
Mustang5L5 said:
Pinout for the 10-pins. I would verify the injectors are pinned properly.

Red is your 12V+ on all the injectors. Center pin on the black connector. So just ring out all your other injectors to the location on the engine. For instance Pin 2. Ignore the wire color and just go to injector 2 (2nd one back pass side) and test continuity from the non-red wire to pin 2 on the 10pin and see if you have it. Try this for all the injectors you can reach without pulling the intake and see if they match up.

Ignore the wire color and just test pin 6 from the white connector out to the ACT plug and verify the wire is intact and you have it.

Click to expand...
Continuity check, brilliant.
 
Reactions: General karthief

limp

wrap a little cheese around it and its a done
5 Year Member
Oct 4, 2020
5,467
2,901
173
Florida
Jan 29, 2024
#74
  • Jan 29, 2024
  • #74
b_arrington said:
Continuity check, brilliant.
Click to expand...
You are getting some good help from one of the better advisors on this site...
 
Reactions: Mcmahst

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Jan 29, 2024
#75
  • Jan 29, 2024
  • #75
b_arrington said:
This is so confusing and frustrating. So many different documents and first hand reports of different colors for the same connector. Some diagrams say ACT signal should be Green/Pink. Others say gray. Some guys say theirs is green/purple. None seem to be matching up with what I'm actually seeing.
Click to expand...

It depends on which vehicle the harness is from. The injector harness differs for all the 80's and 90' 302 vehicles. You'd think Ford would have made one harness for all but they didn't. Wire colors differ as well, which is one clue that you are working with a possibly incorrect wiring harness.

As of right now we are assuming the harness on your car is a 1993 mustang harness but it's not been exactly confirmed. It's always possible subharnesses are not from that vehicle. Wiring harnesses are often the most mis-labeled parts I see for sale. Many sellers just assume "They are all the same".

Given that your ACT harness color doesn't match, i wonder if your injector harness is correct. If it's from a batch fire, speed density vehicle, then the injectors won't be in the correct sequence. So this could be an important task to check. You can start by seeing if the wiring colors align to the pins in post 69 and then continuity check the injectors to the corresponding pins and see if they line up to where they should be on a Mustang,

If incorrect, it can be repinned, but lets cross that bridge when we get there.
 
Reactions: b_arrington and General karthief

Mcmahst

5 Year Member
Jan 19, 2021
681
267
83
Laguna Woods CA, fort Mohave AZ
Jan 29, 2024
#76
  • Jan 29, 2024
  • #76
I think we arrived at 1993 from the ECU ID. I now think that was a leap of faith. If it’s any consolidation, something I’ve noticed Ford does for wiring. It seems, if you go back to the 1960’s, 1970’s, etc, you find, for a particular car type, Mid sized, large size, trucks, etc, they’ve kept similar functions with similar color wires. I noticed that on a 72 Ford pickup project 10 years ago to my now, 73 Mustang with 87 TBird transplant. Between the TBird and old Mustang, so many wires from both that had the same/simular function, had identical wire id’s.

I know that doesn’t help this situation, but it seems, the wire harness on this car is as already mentioned, not likely a passenger car wiring package. I wonder if under those wire covers, there is an Eng I’d number that would I’d what it’s from?

In any case, I think your issue wins the award for the most-needing-to-be-a-detective award.
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,896
4,020
183
Claremore, OK
Jan 29, 2024
#77
  • Jan 29, 2024
  • #77
It very well could be the injector harness off the T-Bird. Do the wire colors match on either side of the connectors i.e. injector harness colors to engine harness colors? I may have missed it but I only saw pictures of the white plug on the "engine side" which I am assuming is on the injector harness.

Also, the ECU harness having both the A/c compressor relay and fuel pump relay by the mass air meter tell you that it is a 92/93 harness or the Ford Racing harness which is based off the 92/93 harness.
 
Last edited: Jan 29, 2024

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Jan 29, 2024
#78
  • Jan 29, 2024
  • #78
The main reason this may be an issue is because the non-HO engines used a different firing order. Two injectors are swapped.

So the passenger car and truck engines use the non-HO order and the mustangs and mark 7 use the 351 order.

The engine will run, but main symptom is poor fuel economy.

Question, did you ever run the cylinder balance test procedure at the end of the code reading process?

I could be barking up the wrong tree here and the act is the final issue you need to solve, but the fact your wire colors are incorrect makes me wonder about that injector sub harness
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,260
17,944
224
Massachusetts
Jan 29, 2024
#79
  • Jan 29, 2024
  • #79
To make things more confusing, the 1993 EVTM lists the ACT wire colors as Gray/Red and Gray

I think I would focus less on wire colors, and more on continuity checks to the various pins to validate correct wire routing.

 
T

ta66

Member
Jan 30, 2024
4
6
13
NY
Jan 30, 2024
#80
  • Jan 30, 2024
  • #80
Hi all, I’m @b_arrington ’s son. We finished the continuity tests and I think we’ve figured it out! Long story short, we confirmed continuity to all pins and their intended sensors, except for pins 6 and 10. We were reading pin 10 as the ACT, and didn’t know what pin 6 went to because it should’ve been the ACT. We then realized that pin 10 should’ve been the CANP, but we don’t have one of those and so whoever put together the engine switched the ACT and CANP plugs. We confirmed this with another test after finding the CANP wire.
 
Reactions: slow84lx, Blue_67Vert, LILCBRA and 2 others
Prev
  • 1
  • 2
  • 3
  • 4
  • 5
Next
First Prev 4 of 5 Next Last
You must log in or register to reply here.

Similar threads

J
Wheels-Tires Need Some Help - Brakes Upgrade/Wheel fitment
  • jaygee15
  • Dec 8, 2025
  • Fox 5.0 Mustang Tech
  • 3 4 5
Replies
81
Views
3K
Fox 5.0 Mustang Tech May 6, 2026
AeroCoupe
Engine Information that is Needed When You Post a "Car is not Running" or "Car is Running Poorly" Thread
  • AeroCoupe
  • Apr 28, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
29
Views
1K
Fox 5.0 Mustang Tech May 4, 2025
Bullitt347
Brakes ABS in a Fox - Mark Bettin
  • AeroCoupe
  • Mar 28, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
26
Views
1K
Fox 5.0 Mustang Tech May 17, 2025
AeroCoupe
Place to Avoid: Jamison Auto Group in Gulfport, MS
  • D Durden
  • Oct 20, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
46
Views
3K
1965 - 1973 Classic Mustangs -General/Talk- Jul 16, 2026
Noobz347
Nice Sn95. 100k miles. Heirloom. Garage kept. We need some help
  • Jacobn4056.
  • Jan 17, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 22, 2024
90sickfox
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
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?