Resolved No run or idle

T

Thebluefox1

Member

Jun 28, 2022

32

3

8

Pasadena

Oct 10, 2025

#1

• Oct 10, 2025

• #1

Hi everyone, I wanted help with my car I have read a lot of threads and checked multiple things. It's a 90 5.0 aod

It was running good before just making noise so I rebuilt it and put gt40p heads with springs, tfs stage 1 cam and cobra intake the throttle Body is bigger but the MAF is stock (I'm trying to get one to match but I'm not sure if this is all I need to fix it.)

The problem i have is that it doesn't want to rev past 2k or it will be in idle and have cuts. when I was messing with it, it reved up with no problem but I haven't been able to replicate it. I put smoke machine and no leaks i put a video if yall can hear it

View: https://youtube.com/shorts/YY-zzaN2KkU?si=4nAvCmcgEgKIMMRE

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

5,806

3,941

183

Claremore, OK

Oct 10, 2025

#2

• Oct 10, 2025

• #2

Here we go…have you pulled codes?

 

T

Thebluefox1

Member

Jun 28, 2022

32

3

8

Pasadena

Oct 10, 2025

#3

• Oct 10, 2025

• #3

AeroCoupe said:

Here we go…have you pulled codes?

Click to expand...

Sorry, yes it has 32 O evp voltage, 84 O egr Regulator, 18 c spout circuit( but i checked and it does advance timing connected), 22 C bap, 32 C egr, and 63 no letter so I'm not sure it really doesn't change with the egr in the system or not

 

Mindseye007

5 Year Member

Oct 21, 2020

561

131

63

ontario

Oct 19, 2025

#4

• Oct 19, 2025

• #4

Thebluefox1 said:

Hi everyone, I wanted help with my car I have read a lot of threads and checked multiple things. It's a 90 5.0 aod

It was running good before just making noise so I rebuilt it and put gt40p heads with springs, tfs stage 1 cam and cobra intake the throttle Body is bigger but the MAF is stock (I'm trying to get one to match but I'm not sure if this is all I need to fix it.)

The problem i have is that it doesn't want to rev past 2k or it will be in idle and have cuts. when I was messing with it, it reved up with no problem but I haven't been able to replicate it. I put smoke machine and no leaks i put a video if yall can hear it

View: https://youtube.com/shorts/YY-zzaN2KkU?si=4nAvCmcgEgKIMMRE

Click to expand...

how is the ECU ? did you check the caps?

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

5,806

3,941

183

Claremore, OK

Oct 19, 2025

#5

• Oct 19, 2025

• #5

Are you sure you got the distributor reinstalled at TDC and the firing order is right?

 

Reactions: DadLife0724

T

Thebluefox1

Member

Jun 28, 2022

32

3

8

Pasadena

Oct 19, 2025

#6

• Oct 19, 2025

• #6

Mindseye007 said:

how is the ECU ? did you check the caps?

Click to expand...

I haven't checked the computer but my battery wasn't holding charge so I changed it and now it revs up but it still has a "cut" when i keep it at certain place, so now maybe it's just a misfire?

 

T

Thebluefox1

Member

Jun 28, 2022

32

3

8

Pasadena

Oct 19, 2025

#7

• Oct 19, 2025

• #7

AeroCoupe said:

Are you sure you got the distributor reinstalled at TDC and the firing order is right?

Click to expand...

Yes I checked multiple times, if I move the "salt and pepper" connector I think it changed the idle but I had looked at them and they didn't look broken, would that give a misfire

 

DadLife0724

Active Member

Mar 22, 2024

262

189

53

Cooperstown, PA

Oct 19, 2025

#8

• Oct 19, 2025

• #8

AeroCoupe said:

Are you sure you got the distributor reinstalled at TDC and the firing order is right?

Click to expand...

Thats where I'd be looking.

 

Mindseye007

5 Year Member

Oct 21, 2020

561

131

63

ontario

Oct 19, 2025

#9

• Oct 19, 2025

• #9

Thebluefox1 said:

I haven't checked the computer but my battery wasn't holding charge so I changed it and now it revs up but it still has a "cut" when i keep it at certain place, so now maybe it's just a misfire?

Click to expand...

I would check the Ecu it might need a repair .
Open it up post a picture of it and Send it here if it does need a repair best place to repair it.

Ford Mustang 5.0 A9L A9P C3W A3M X3Z ECU Repair Service

Ford Mustang 5.0 A9L A9P C3W A3M X3Z ECUEngine Computer Repair ServicePlease fill out the R&R form here once you've placed your order.A Trusted Product with LIFETIME WARRANTY QUICK TURN AROUND TIMEDomestic and International Shipping available! Our Team is Available Monday - Friday 9am to 5pm...

www.theecuexchange.com

 

Last edited: Oct 19, 2025

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T

Thebluefox1

Member

Jun 28, 2022

32

3

8

Pasadena

Oct 19, 2025

#10

• Oct 19, 2025

• #10

Mindseye007 said:

I would check the Ecu it might need a repair .
Open it up post a picture of it and Send it here if it does need a repair best place to repair it.

Ford Mustang 5.0 A9L A9P C3W A3M X3Z ECU Repair Service

Ford Mustang 5.0 A9L A9P C3W A3M X3Z ECUEngine Computer Repair ServicePlease fill out the R&R form here once you've placed your order.A Trusted Product with LIFETIME WARRANTY QUICK TURN AROUND TIMEDomestic and International Shipping available! Our Team is Available Monday - Friday 9am to 5pm...

www.theecuexchange.com

Click to expand...

Ok thank you, I'll take it out and take a picture

 

Reactions: Mindseye007

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

5,806

3,941

183

Claremore, OK

Oct 19, 2025

#11

• Oct 19, 2025

• #11

We are seeing all kinds of issues with these processors as they age. Right now an ECU out of a 1993 car is literally 32 years old. Some of the components are aging out and failing. Some are just sending them off to ECau Wxchange to have them go through it for a piece of mind. I had mine done about 20 years ago (bought a bad one when I swapped the car) and it’s still rock solid. Something to think about as a winter project if you are lucky enough to park the car for the winter.

 

gkomo

now i can hopefully expect to receive the shaft

Aug 2, 2024

2,136

1,374

133

San Diego, CA

Oct 19, 2025

#12

• Oct 19, 2025

• #12

Or if you can afford for it to be down for a few weeks at most. My ECUexchange was 3 weeks from shipping to delivery. Worth it anyways even you don’t suspect anything wrong.

 

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DadLife0724

Active Member

Mar 22, 2024

262

189

53

Cooperstown, PA

Oct 19, 2025

#13

• Oct 19, 2025

• #13

This is my ECU I swapped out couple months ago. Just an example of what to look out for. The issues this caused made me rethink my entire life.

 

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T

Thebluefox1

Member

Jun 28, 2022

32

3

8

Pasadena

Nov 24, 2025

#14

• Nov 24, 2025

• #14

Sorry I haven't been able to work on it the problem it had was the distributor. The new one I put was bad out of the box, I put an oem and it's working good now thank for your replies and help

 

Reactions: DadLife0724 and Mindseye007

DadLife0724

Active Member

Mar 22, 2024

262

189

53

Cooperstown, PA

Nov 25, 2025

#15

• Nov 25, 2025

• #15