Where To Find Mass Air Ecu For My Engine?

[mac16]

Hey guys I have had my car in the shop for a while now, and its come time to get a new ecu. I need to find one for my mass air converted 88, and for 30# injectors. My mechanic seems to be having a tough time locating one on his own.

Which exact ecu do i need?

Is this something that needs to be custom programmed, or can you buy them already set for 30# injectors. Sorry I dont know much about ECUs. This is the last thing I need to get my car running again.

Thanks!

 

[jrichker]

You need an A9L or A3M computer and a Pro-M MAF calibrated for the 30 LB injectors. There is no OEM Ford replacement computer calibrated to use the 30 LB injectors. That is done by using the appropriate aftermarket MAF or a custom burned chip from a dyno tune run.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

Computer & interchange information for 5.0 Mustang

Revised 16-Oct-2011 to add O2 sensor harness warnings

The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I would recommend avoiding using a 5 speed computer in an auto trans car due to the possibility of damaging the computer’ internal signal ground circuitry.

The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.

Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a 5 speed trans O2 harness with an A9L. Do not run an Auto O2 sensor harness with an A9L. Doing so will damage the computer’s internal signal ground.
Only run an Auto trans O2 sensor harness with an A9P in a car that has an Auto trans. Using a 5 speed trans O2 sensor harness with an Auto trans will cause no crank problems.
See http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor- harnesses-manual-auto-differences-year-differences.html for more O2 sensor wiring harness info
If you have a damaged computer with signal ground problems, See http://www.stangnet.com/mustang-forums/749974-computer-issue.html#post7490537 for Joel5.0’s fix to the computer internal signal ground.

All the following are mass air unless they say Speed Density
8LD - MANUAL 88 5.0L Mustang Mass Air - California
8LF - Auto 88 5.0L Mustang Mass Air- California
8LG - Auto 88 5.0L Mustang Mass Air- California
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - 88 Lincoln LSC Speed Density

See http://oldfuelinjection.com/?p=17 for more computer types

 

[jcgafford]

orielly auto parts has bwd remans.... got mine there.

 

[mac16]

You need an A9L or A3M computer and a Pro-M MAF calibrated for the 30 LB injectors. There is no OEM Ford replacement computer calibrated to use the 30 LB injectors. That is done by using the appropriate aftermarket MAF or a custom burned chip from a dyno tune run.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

Computer & interchange information for 5.0 Mustang

Revised 16-Oct-2011 to add O2 sensor harness warnings

The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I would recommend avoiding using a 5 speed computer in an auto trans car due to the possibility of damaging the computer’ internal signal ground circuitry.

The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.

Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a 5 speed trans O2 harness with an A9L. Do not run an Auto O2 sensor harness with an A9L. Doing so will damage the computer’s internal signal ground.
Only run an Auto trans O2 sensor harness with an A9P in a car that has an Auto trans. Using a 5 speed trans O2 sensor harness with an Auto trans will cause no crank problems.
See http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor- harnesses-manual-auto-differences-year-differences.html for more O2 sensor wiring harness info
If you have a damaged computer with signal ground problems, See http://www.stangnet.com/mustang-forums/749974-computer-issue.html#post7490537 for Joel5.0’s fix to the computer internal signal ground.

All the following are mass air unless they say Speed Density
8LD - MANUAL 88 5.0L Mustang Mass Air - California
8LF - Auto 88 5.0L Mustang Mass Air- California
8LG - Auto 88 5.0L Mustang Mass Air- California
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - 88 Lincoln LSC Speed Density

See http://oldfuelinjection.com/?p=17 for more computer types

My car already has already been converted to mass air, and before that the car ran great. You can see the details in my sig, i bought the car the way it was. I had the engine swapped into a new body and in the process my old ecu got misplaced. I believe the old one was an a9l. So any off the shelf a9l computer will run the car?

 

[f8tlfiveo]

A9p will work too.. I have a 5 speed and auto computer.. Don't let anyone tell you different. It has been fine for years

 

[jcgafford]

both a9l and a9p were available as of last night when i did the search. you shouldnt have to even consider running anything but the "correct" brain.

 

[Gearbanger 101]

A9p will work too.. I have a 5 speed and auto computer.. Don't let anyone tell you different. It has been fine for years

This. When I did the auto to T-5 swap to my last car ('87 LX) I kept the auto ECU. Worked like a charm. Going from 5-speed to auto on the other hand....then you're going to need to swap out the computer.

 

[My92Vert]

Ok. so i see that some are saying it doesn't matter if you run a automatic ecm in a stick or the. automatic one. If this is true can someone tell me why my converted auto to a stick idles high using a automatic ecm?? I'm at a loss. I've already replaced the tps, coolant sensor, air charge sensor. Sometimes when I go over hard bumps it jumps to even a higher idle before settling down to an idle about 1300.Any ideas would help.

 

[gearheadboy]

Did you consider cleaning the IAC, throttle plate, and MAF? I had one act this way and it had a faulty TPS.

 

[jcgafford]

have you ever reset the idle manually?

 

[jrichker]

See the "Surging Idle Checklist” for help with all your idle/stall problems. You can guess at the problem and throw parts at it, or you can use the checklist to help you find the problem quickly and inexpensively. The checklist is right here in the Stangnet 5.0 Tech forum and you don’t have navigate to some other unknown web site. It‘s free and doesn’t cost anything: at last count there were more than 103,000 visits and still climbing

The quick and easy way to dump the codes is in there too, and all you need to do it is a paper clip! The first two posts contain all the fixes & updates. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

 

[My92Vert]

Ok. so i see that some are saying it doesn't matter if you run a automatic ecm in a stick or the. automatic one. If this is true can someone tell me why my converted auto to a stick idles high using a automatic ecm?? I'm at a loss. I've already replaced the tps, coolant sensor, air charge sensor. Sometimes when I go over hard bumps it jumps to even a higher idle before settling down to an idle about 1300.Any ideas would help.

Ok so today I installed an A9M from a doner car, the idle dropped down to normal, but still only starts when throttle is held wide open and idle drops kinda slow between shifts.......

 

[88LX5.Oh]

Thread jacking FTW!