Topic: Yj computer vs. Tj computer.

[turbojeep95]

I know that one of the main differences between the two is obdI and obdII.  Also, that the yj computer doesn't like to adjust very well to mods and tries to bring it back to stock. This also seems to be why there are no computer chips out there for the yj 2.5L.  What all would be involved in swapping a tj ecu into a yj?  I know the main thing I could think of would be the addition of the fuel return line. One other advantage I could think of would be for the turbo crowd.  The obdII seem to be known to handle turbo tunes better, plus with the addition of the return line would make running an fmu possible.  Just some ideas that I had. Let me know what you guys think.

[sharpxmen]

I know that one of the main differences between the two is obdI and obdII.  Also, that the yj computer doesn't like to adjust very well to mods and tries to bring it back to stock. This also seems to be why there are no computer chips out there for the yj 2.5L.  What all would be involved in swapping a tj ecu into a yj?  I know the main thing I could think of would be the addition of the fuel return line. One other advantage I could think of would be for the turbo crowd.  The obdII seem to be known to handle turbo tunes better, plus with the addition of the return line would make running an fmu possible.  Just some ideas that I had. Let me know what you guys think.

not worth it, same issues you have with the YJ computer you'll have with the TJ one - what you mean by "doesn't like to adjust very well to mods" is the fact that the PCM (in both TJ and YJ) will target 14.7AFR in closed loop. For the trouble and the money (since you'll still need a piggyback unit to fine tune the AFR) might as well go aftermaket ECU with wideband O2 sensor.

[dwtaylorpdx]

+1 I have pretty much given up on the Jeep ECU... Even with a scanner for the OBD1 its a pig. bad fuel curves when stock much less when built...

Dave

[sharpxmen]

I came across this one
http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=FS&Product_Code=302000&Category_Code=

self tuning wideband, don't know much about it though - for $900 beats the heck out of even megasquirt (it includes the wiring harness and wideband o2 sensor) but that depends on the features (yet to see the manual for it but I didn't look)

[dwtaylorpdx]

From what I've heard and this is second hand,,, The ez-tune is good for built NA motors, but not smart enough for hard boost.

I've used a few of their products and they performed well, no issues, But have not tried their EFI....

Dave

[sharpxmen]

you're right, seems to be limited - I sent them an email last night inquiring about the features and tuning procedures and this is the response i got:

The EZ EFI does not allow for manual tuning as the self tuning software
takes care of everything for you. It comes with a handheld unit that can be
used to monitor and make your inputs as to the setup it is on but does not
require a PC/lap top unit for anything nor does it allow for it, since it is
simply not needed. If you want something that you can tune yourself then you
need to look at our XFI kit and not the EZ.

I did ask for the user's manual and got no answer on that one, i find it weird that they did not have one of those online

[Torch_Ind]

yj and tj computers are a large difference.

I would go piggy back or stand alone if you want it for mods.

the yj being obdII should be able to re-flash and update software but it's finding someone that can do it and knows what there doing. 

yj is solid state and would require extensive electronics work done to make it reprogrammable. hints NOT WORTH IT. it would be like trying to run windows 7 on a old 486 or Pentium 1 computer lol to get what you want out of it.

I have seen those easy efi systems and they seem more carb replacement based, taking a old hot rod and running a tbi set up. from what I have seen also powerblocktv did a show on it.

[sharpxmen]

yj and tj computers are a large difference.

I would go piggy back or stand alone if you want it for mods.

the yj being obdII should be able to re-flash and update software but it's finding someone that can do it and knows what there doing. 

yj is solid state and would require extensive electronics work done to make it reprogrammable. hints NOT WORTH IT. it would be like trying to run windows 7 on a old 486 or Pentium 1 computer lol to get what you want out of it.

I have seen those easy efi systems and they seem more carb replacement based, taking a old hot rod and running a tbi set up. from what I have seen also powerblocktv did a show on it.

what type of microprocessors are in the TJ and YJ ecu? just out of curiosity, i don't know the answer to that question.

[dwtaylorpdx]

I think its Delphi... the assembly anyway...  Not sure of the CPU... But if I ever scroungs a unit to hollow out to hide a decent stand alone I'll be checking... LOL

Dave

[sharpxmen]

I was reading about the Camaro 3rd gen computer at some point (i have one of those which is my DD at this time) - to reprogram/reflash that one you have to unsolder to remove the factory PROM, solder in a socket and use an EEPROM (electrical erasable PROM) - you flash it outside the ECU, then plug it in the socket - if you need to update the code, you have to remove it, burn it again and put it back in.

[Torch_Ind]

I think its Delphi... the assembly anyway...  Not sure of the CPU... But if I ever scroungs a unit to hollow out to hide a decent stand alone I'll be checking... LOL

Dave