I have opened and compared both the NA and turbo ecu.

thanks. last night i pulled apart EA82T and XT6 ECU's and they are identical except the XT6 has 3 resistors in one area where the EA82T has 2. same resistors, just one extra. the EA82T has a spot marked and labeled for one, it's just not there. i actually plugged the XT6 ECU into my EA82 and it fired right up and drove great! idled high at about 2,000 rpms, but otherwise drove great to my surprise!! all connectors were identical even. the EA82T ECU's are "bad" i believe but i didn't see any bad connections or friend resistors/transistors inside.

 

i ordered another ECU since both EA82T ECU's i have don't run when installed.

 

i'm still completely puzzled that the RX ECU would prime the fuel pump, flashed 2 codes but wouldn't spark.

and the XT Turbo ECU would show no codes, sparked fine but would run the fuel pump. hard wiring the fuel pump i could get it to start but it wouldn't run at all. i could only keep it running by varying the gas pedal intensely...holding it steady would make it cut out. oh well, they are junk ECU's i suppose.

 

thanks for the help guys!

I have opened and compared both the NA and turbo ecu. The circuit boards are exactly the same, except that the turbo ecu has an extra transistor...

 

I haven't actually seen one of the boards in question, but:

Just because all the circuit board traces are the same doesn't mean that the chips on the board are programmed the same, or have the same pin connections.

 

Call me crazy, but WRONG ECU is the very FIRST thing I would suspect to cause the problems Gary has been having.

I think a N/A motor should have a N/A ecu. Also, I would match SPFI and MPFI N/A motors to matching ECUs.

 

What ECU do you have coming?

Just because all the circuit board traces are the same doesn't mean that the chips on the board are programmed the same, or have the same pin connections.

of course. but, they used one platform to create the other so similarities could be enormous and that was proved when the XT6 (6 cylinder) ECU worked on my XT (4 cyilnder) engine. the other two were fried ECU's. the XT6 ECU ran great, perfectly smooth. i agree, i would think it would cause issue. i can't believe i didn't get any IAC valve (a component only on the XT6 ER27 engine) or other issues....but i didn't. car ran great. idled high...which confuses me since the throttle plate is closed and the AAV valve wasn't connected. ran great, that's all i know.

 

Call me crazy,

you're crazy

 

What ECU do you have coming?

1989 XT non-turbo

 

i agree, probably best to have the right ECU and one is on the way.

Just because all the circuit board traces are the same doesn't mean that the chips on the board are programmed the same, or have the same pin connections.

 

I realise that there will be differences, but as gary said, they are built on the same platform, including minor differences to suit the motor they are designed for. Like knock control and a larger fuel map for the turbo, and ability do drive more injectors on the 6cyl one.

 

I was actially surprised that the XT6 ecu was compatable, but...it is almost the same engine with 2 extra cylinders, so the ecu fuel maps are probably larger.

 

Gannon

I have opened and compared both the NA and turbo ecu. The circuit boards are exactly the same, except that the turbo ecu has an extra transistor (this is to drive the WGDS, .... which acts as a control to maintain max turbocharging pressure at higher altitudes, where air density/pressure is less)

The turbo ecu also has a 2nd circuit board mounted about 3/4 inch above the main board, this is the knock control unit.

They are the only 2 differences that i can see.

 

Gannon

 

thanks. last night i pulled apart EA82T and XT6 ECU's and they are identical except the XT6 has 3 resistors in one area where the EA82T has 2. same resistors, just one extra. the EA82T has a spot marked and labeled for one, it's just not there. i actually plugged the XT6 ECU into my EA82 and it fired right up and drove great! idled high at about 2,000 rpms, but otherwise drove great to my surprise!! all connectors were identical even. the EA82T ECU's are "bad" i believe but i didn't see any bad connections or friend resistors/transistors inside.

 

These two quotes are interesting. Does this mean that if you wanted to turbocharge your XT6, you could use an XT turbo or RX turbo ECU to do the dirty work instead of MSDS?

These two quotes are interesting. Does this mean that if you wanted to turbocharge your XT6, you could use an XT turbo or RX turbo ECU to do the dirty work instead of MSDS?

i thought about that as well but i'm almost certain it wouldn't work.

 

with some customizing you could use EA82T injectors on the XT6, the EA82T ECU to drive them and just duplicate the signals for the other two injectors, but then you'd have to time them properly anyway....which is a MS-like process. extra injector and stock XT6 ECU is the way to go without getting into stand alones.

but hey.....there's always one way to find out! do it! when i get the turbo on mine i'll swap in an EA82T ECU and see what happens.