Just another Jeep guy

[WallyCJ7]

Hello everyone.
I have came to that point when I'm sick on the way my TBI is performing and after thinking I have the answer to the problem wrong...

So here's the deal. I have a AMC 401 bored .030 over 9.8:1 compression, Crane Cam H-260-2, TBI from a 454 (17087021) with 80lbs injectors.

The original system was made by Custom EFIS back in about 2003 I think and it was setup for my old 304 and I always had an issue with WOT.
I changed motor back in 2006 and it has never run right the whole time.
After dealing with the guy several times trying to tune it I got nowhere so here I am.

Well it's time to make this thing work or start building a TPI system.

Wally

[dave w]

I'm wondering ... what ignition system are you using? I recommend using an ignition system that has the GM 8 pin module with the GM remote TBI ignition coil.

dave w

[1project2many]

Maybe the rotor mount is outrunning the distributor shaft? Maybe the original tune wasn't made correctly?
http://lists.diy-efi.org/pipermail/g...ay/005046.html
(The poster is John of CustomEFIS)

We can probably help. The TBI system could provide reasonable performance with that cam. I wonder how close the CustomEFIS calibration is and whether or not it's worth it to work with that one or to start from scratch. Did you get a Duraspark conversion distributor with the EFI kit or is it using an HEI pickup coil? Also, I'm not an AMC guy but as a general rule 9.8 is considered a fairly high compression ratio. What are you using for fuel? Are the chambers and pistons ceramic coated?

[WallyCJ7]

I'm wondering ... what ignition system are you using? I recommend using an ignition system that has the GM 8 pin module with the GM remote TBI ignition coil.

dave w

I have the GM 8 pin module, I'm running a MSD distributor and a Jacobs coil.

[WallyCJ7]

Maybe the rotor mount is outrunning the distributor shaft? Maybe the original tune wasn't made correctly?
http://lists.diy-efi.org/pipermail/g...ay/005046.html
(The poster is John of CustomEFIS)

We can probably help. The TBI system could provide reasonable performance with that cam. I wonder how close the CustomEFIS calibration is and whether or not it's worth it to work with that one or to start from scratch. Did you get a Duraspark conversion distributor with the EFI kit or is it using an HEI pickup coil? Also, I'm not an AMC guy but as a general rule 9.8 is considered a fairly high compression ratio. What are you using for fuel? Are the chambers and pistons ceramic coated?

The worst part was I sent C-EFIS a different ECU 7747 (probably the wrong number)that was from a 6 cylinder and he converted it to use a chip that I could burn at home. I seen a post here about the mod using the flash burn chip and I think its the same setup. The first set up he sent was still running a 6 cylinder and it pinged like crazy. I'm almost thinking I should dump the whole thing as start over with something that is running good in a AMC 360 or 401 or maybe a 454 as a good baseline. There is no advance on the distributor so everything is done thru the ECU.

I always use premium fuel or better. Keep in mind that this is a rock crawler that hardly ever sees the highway

The hard part will be testing this thing since I'm running 39.5 x 14 tires that don't like the highway at all. Maybe I'll have to find some pizza cutter tire to test with.

[dave w]

I have the GM 8 pin module, I'm running a MSD distributor and a Jacobs coil.

Those ignition parts you are using should be OK. I was wondering if maybe you were using the old point style ignition coil, which does not function correctly with the GM 8 pin module and 7747 ECM.

I'd really like to see a data log.

dave w

[WallyCJ7]

I'd really like to see a data log.

dave w

I guess I need to log some data, its been a long time since I did it. I need to find some street-able tire to run first.

[dave w]

I guess I need to log some data, its been a long time since I did it. I need to find some street-able tire to run first.

I understand the challenges of getting enough "closed loop" data with the '7747 to be useful.

The attached .xdf has a "patch" to enable the spark timing to be seen in the data log, which is very helpful.

The attached .adx is very helpful also.

dave w

[WallyCJ7]

I understand the challenges of getting enough "closed loop" data with the '7747 to be useful.

The attached .xdf has a "patch" to enable the spark timing to be seen in the data log, which is very helpful.

The attached .adx is very helpful also.

dave w

I'll figure out how to use these when I get back from a trip to Minnesota the week. SoCal guy use to the 80 deg going to the teens should be fun :)

[1project2many]

I'll figure out how to use these when I get back from a trip to Minnesota the week. SoCal guy use to the 80 deg going to the teens should be fun :)

Haha... so if we ask for a "freeze frame" of the computer data after you get back, it's likely to make your teeth chatter?

[JeepsAndGuns]

Do you know for sure which ecm your running? Is it a 1227747? And do you know what all changes have been made to the current bin file? If it is unknown, it might be almost worthwhile to start with a fresh factory bin and go from there, that way you know what all changes have been made, and only do them one at a time to see if they improve or not.


In a way, I really want to reccomend a swap to a 16197427 pcm. I did that on mine and it was a very noticeable difference from a 1227747. With the 7427, you have a faster pcm, faster data logging, a lot more parameters and controll. You will also have the ability to add a e-trans if you ever wanted (4L60E/4L80E) and there is even code and mods you can do to convert it to run MPFI. Thats wht I did on my AMC 401.

Things I have learned from tuning a AMC engine. Timing! they love timing! Every stock chevy timing map I tried ran like doo-doo. Once I started adding timing it really woke my engine up. That also leads me to knock sensors. Dont bother. I have tried and tried to get one working. I have tried mounting it in different locations, different knock modules, adding a elbow to the sensor, nothing worked. All it does it pick up everything but knock. I gave up and tuned timing by ear. Not the best way, but the only way I could do it. When I had TBI, I also had the 454 unit and injectors. The injectors were borderline too big for a mild 401. I had to run 12 psi and tune the fuel maps way down.

Your 401 is not much different from mine. I am .040 over, stock style pistons, heads shaved about .020, ported/polished, comp 256H-XE cam, long tube headers. I am running a modded edlebrock pro flow mpfi intake (with my own junkyard throttle body and bosch gen 3 style injectors) When I was running TBI I was running a edelbrock performer.

[WallyCJ7]

Do you know for sure which ecm your running? Is it a 1227747? And do you know what all changes have been made to the current bin file? If it is unknown, it might be almost worthwhile to start with a fresh factory bin and go from there, that way you know what all changes have been made, and only do them one at a time to see if they improve or not.


In a way, I really want to reccomend a swap to a 16197427 pcm. I did that on mine and it was a very noticeable difference from a 1227747. With the 7427, you have a faster pcm, faster data logging, a lot more parameters and controll. You will also have the ability to add a e-trans if you ever wanted (4L60E/4L80E) and there is even code and mods you can do to convert it to run MPFI. Thats wht I did on my AMC 401.

Things I have learned from tuning a AMC engine. Timing! they love timing! Every stock chevy timing map I tried ran like doo-doo. Once I started adding timing it really woke my engine up. That also leads me to knock sensors. Dont bother. I have tried and tried to get one working. I have tried mounting it in different locations, different knock modules, adding a elbow to the sensor, nothing worked. All it does it pick up everything but knock. I gave up and tuned timing by ear. Not the best way, but the only way I could do it. When I had TBI, I also had the 454 unit and injectors. The injectors were borderline too big for a mild 401. I had to run 12 psi and tune the fuel maps way down.

Your 401 is not much different from mine. I am .040 over, stock style pistons, heads shaved about .020, ported/polished, comp 256H-XE cam, long tube headers. I am running a modded edlebrock pro flow mpfi intake (with my own junkyard throttle body and bosch gen 3 style injectors) When I was running TBI I was running a edelbrock performer.

I'm back for the -2 degrees in Minnesota.

Yes the ECU is a 1227747. I'm interested in the 16197427 pcm if it works with my current wiring. What year GM does that come out of?
No knock sensor.
The distributor has no mechanical advance, the ECU controls everything. I think the base timing is set @ 10 degrees with the wire disconnected.

I found my current files that I'm running and the .LOG and .BLM files that I sent him to make the changes.
The thing he changed was he took out an average of 4 degrees advancement.

[WallyCJ7]

I understand the challenges of getting enough "closed loop" data with the '7747 to be useful.

The attached .xdf has a "patch" to enable the spark timing to be seen in the data log, which is very helpful.

The attached .adx is very helpful also.

dave w

Are these file to be used with WINALDL?

[dave w]

Are these file to be used with WINALDL?

The 16197427 will not work ( plug - n - play ) with the 1227747 wiring. I'm figuring upgrading to the 16197427 is not an option, because you will need re-wiring the 1227747 computer connectors to upgrade.

I posted files for TunerPro RT.

I do not mean any personal disrespect toward you, I've stopped using WinALDL. The information provided by TunerPro RT is more comprehensive, better organized, and more useful.

dave w

[WallyCJ7]

The 16197427 will not work ( plug - n - play ) with the 1227747 wiring. I'm figuring upgrading to the 16197427 is not an option, because you will need re-wiring the 1227747 computer connectors to upgrade.

I posted files for TunerPro RT.

I do not mean any personal disrespect toward you, I've stopped using WinALDL. The information provided by TunerPro RT is more comprehensive, better organized, and more useful.

dave w

None taken, That's just the program I was told to use back in the day... I downloaded the latest version of TurnerPro RT and I do a little reading up on how it works.
I did a search for 16197427 after reading this post and I seen the wiring crossover info.
I've never been fond of the 160 baud rate the 1227747 has and I 'm thinking that is much higher with the 16197427.

I don't know how much bearing this has but my system has a single wire O2 sensor.

Steve