TCCoA Forums banner

1 - 19 of 19 Posts

·
Registered
Joined
·
325 Posts
Discussion Starter #1
Lately, I have tried several different stock PCMs in both of my '97 T Birds. I have been experimenting with '96 and '97 PCMs and have about 8 of them laying around my garage. It might just be my imagination, but some seem to run, and start up much better than others. With some, I get an SES light, another I get pinging, etc. These things are definitly not all created equal. Anyways, I was wondering what year or part number is best for performance with the stock programming. Most of the '96s seem to function better than the '97s I have tried. Right now, I have (2) 96 PCMs in my two 97s. Is all this my imagination or are there better ones out there? I can get any year or p/n cheap at the junkyard with a warranty. What has been your experience with the stock ones? I have never tried a '95 or earlier.

Thanks, Phil
 

·
Premium Member
Joined
·
5,862 Posts
Lately, I have tried several different stock PCMs in both of my '97 T Birds. I have been experimenting with '96 and '97 PCMs and have about 8 of them laying around my garage. It might just be my imagination, but some seem to run, and start up much better than others. With some, I get an SES light, another I get pinging, etc. These things are definitly not all created equal. Anyways, I was wondering what year or part number is best for performance with the stock programming. Most of the '96s seem to function better than the '97s I have tried. Right now, I have (2) 96 PCMs in my two 97s. Is all this my imagination or are there better ones out there. I can get any year or p/n cheap at the junkyard with a warranty. What has been your experience with the stock ones? I have never tried a '95 or earlier.

Thanks, Phil
Phil, in my experience, every time you disconnect the power from the ECM, it runs a lot different when you hook up the battery again. Someone more experienced will chime in I'm sure, but I believe that is because the computer has to learn all values it stuffs in it's fuel-air & spark-adjust tables again as you drive. This is what happens with mine. I DEFINATELY notice the difference when the car has had the battery power removed for any period of time.

That may be what you are experiencing or you might be on to something. Are all the ECMs you have the same catch code? I will tell you this; I have a 1994 ecm in my 1995 and the shift pressure/schedule is DIFFERENT. It shifts softer and seems to slip on the 4-3 shift while it NEVER did that before I changed the ECM.
 

·
Registered
Joined
·
325 Posts
Discussion Starter #3
Rick,

Thanks for the quick response. No, I am not comparing the initial running but the running after the PCMs have had time to adjust in. All different catch codes and part numbers. My best ones both came from 96 Cougars. It would be interesting to compare the advance curves, etc. Or run time trials or on a dynometer. Of course you have to give them time to adjust in.
 

·
Premium Member
Joined
·
5,862 Posts
Rick,

Thanks for the quick response. No, I am not comparing the initial running but the running after the PCMs have had time to adjust in. All different catch codes and part numbers. My best ones both came from 96 Cougars. It would be interesting to compare the advance curves, etc. Or run time trials or on a dynometer. Of course you have to give them time to adjust in.
Dude, this is great info. Because I am going to convert my 94-95 wiring to 96-97 so I can upgrade to a 96-97 ECM. So which catch code have you found runs the best?
 

·
Registered
Joined
·
325 Posts
Discussion Starter #5
I really don't pay attention to catch codes. I look at part numbers and years more. I have not tried enough of them to say for sure, hence this thread. The two that I am running now are P/N F6SF-12A650-DD FROM 96 Cougars. The F7SF-units seem to have a much reduced performance curve. My smog guy tells me that is because the 97 car has to meet tighter emissions than the 96.

Phil
 

·
Premium Member
Joined
·
5,862 Posts
I really don't pay attention to catch codes. I look at part numbers and years more. I have not tried enough of them to say for sure, hence this thread. The two that I am running now are P/N F6SF-12A650-DD FROM 96 Cougars. The F7SF-units seem to have a much reduced performance curve. My smog guy tells me that is because the 97 car has to meet tighter emissions than the 96.

Phil
That makes sense, but from what I can find, the F6SF-DD is a low emission (CA/MA/NY) ECM which would indicate lower performance, but you are getting better? Interesting.....

I guess with an aftermarket tune, it wouldn't matter what ECM you start with, would it?

Here is what I could find in the few minutes I researched. Let me know if this matches what ECMs you have found:

1996 Bird
F5SF-EA low-emission
F6SF-CB -CC -CD std-emission
F6SF-DB -DC low-emission

1996 Cougar
F6SF-CB -CC -CD std-emission
F6SF-DD low-emission
F7SF-BA low-emission

1997 Bird/Cougar
F6SF-DB -DC -DD low-emission
F7SF-BA -BB low-emission
F6SF-CB -CC -CD std-emission
F7SF-AA -AB std-emission
 

·
Newbie
Joined
·
5,650 Posts
Timing is hard-coded and these cars didn't have knock sensors, so the only thing that's going to alter the spark for any given load/rpm is the air temp, coolant temp, octane plug, or EGR flow. The transmission shifts can also affect timing but this is only momentarily.

If the engine runs way different when the KAM is cleared, it's because something is being compensated for. Typically as the cars age the PCM has to learn new values for the IAC and EGR flows because build-up of sludge and carbon restricts the airflow that the PCM knows to start with. There are also the fuel trims that it learns but those should always be near 0 if everything is as it should be.

I have seen the values of a 96 CA (low-emission) PCM and a 97 49-state (standard-emission) PCM and the only difference in the tune as far as adjustable parameters go is the EGR flow rate table and corresponding timing for EGR table and some very minor alterations to the shift schedule and base fuel table. The base timing tables are identical.
 

·
Registered
Joined
·
325 Posts
Discussion Starter #8
Great information Rick. Some of these units are different on an individual basis as well, I think. All of the ones I have found are low emision. Guess that make sense because I live in CA. It would be interesting to run differet ones on a dyno to compare. Not into tuning flashes, etc. Too cheap. Would rather just run the best stock ones. Thanks for the great info.

Phil
 

·
Super Moderator
Joined
·
11,961 Posts
You all are splitting hairs lol

The base fuel table is not adjusted by the pcm...neither are the spark tables...things are only modified when the car isnt running right or due to excessive act/ect's.....not changes for performance

Edit: darn master486 beat me to it lol
 

·
Registered
Joined
·
325 Posts
Discussion Starter #11
You all are splitting hairs lol

The base fuel table is not adjusted by the pcm...neither are the spark tables...things are only modified when the car isnt running right or due to excessive act/ect's.....not changes for performance

Edit: darn master486 beat me to it lol
If this is true, why did Ford go to all the trouble to list and produce all these different part numbers and catch codes? Your local Ford dealer parts department lists about 10 different part numbers too even though all are obsolete. I went there a couple of weeks ago. I am only talking 96 and 97s.

Phil
 

·
Registered
Joined
·
325 Posts
Discussion Starter #12
You all are splitting hairs lol

The base fuel table is not adjusted by the pcm...neither are the spark tables...things are only modified when the car isnt running right or due to excessive act/ect's.....not changes for performance

Edit: darn master486 beat me to it lol
One of my 97s wants to ping all the time on regular. Since these cars don't have knock sensors what can we do. I run premium in it but it still wants to ping on aceleration. This car only has 65K on it. The one that runs perfect has 180K on it.

Phil
 

·
Super Moderator
Joined
·
11,961 Posts
I understand your concern, and you are right that there are subtle differences in the numbers in the tune, but none significant enough to make a stock mn12 ping on 87 octane....if it pings on 87, then its the car, not the pcm
 

·
Super Moderator
Joined
·
10,274 Posts
One of my 97s wants to ping all the time on regular. Since these cars don't have knock sensors what can we do.
Seafoam. It's full of crap.

Also, Check the egr passages; I bet they're full.
 

·
Registered
Joined
·
325 Posts
Discussion Starter #15
I understand your concern, and you are right that there are subtle differences in the numbers in the tune, but none significant enough to make a stock mn12 ping on 87 octane....if it pings on 87, then its the car, not the pcm
I never said I thought it was the PCM. You made a statement that the spark was preprogramed in the PCM. My question was what ELSE can be done about it. I have water injected it and run lotsa Seafoam throgh it and it still pings. If not the PCM, what then?

Phil
 

·
Super Moderator
Joined
·
11,961 Posts
the pcm can adapt (somewhat) for sensors that are out-of-whack....only when sensors are outside of the pre-set boundaries does the SES light come on

also, a sub-par exhaust system can disguise itself as an engine problem...too much backpressure and too much hot, residual exhaust gases remain in the cylinder, raising the combustion chamber temperatures that the pcm has no way of knowing
 

·
Registered
Joined
·
30 Posts
That makes sense, but from what I can find, the F6SF-DD is a low emission (CA/MA/NY) ECM which would indicate lower performance, but you are getting better? Interesting.....

[I guess with an aftermarket tune, it wouldn't matter what ECM you start with, would it?]

Exactly you going to be getting a tune anyhow to dial in mods. Just find a good unit.
uuuuhhhh I Said unit uuuhhhhaha:tongue:
 
1 - 19 of 19 Posts
Top