ecu upgrade

[mark corbitt]

I have an 87 4,0 4x4  and  according to build sheet an 5-45RFE automatic transmission, which ECU should I upgrade to?

[87MJTIM]

You want one from a 89-90 MJ or XJ with auto transmissions. 

 

I don’t recall the part number. 

 

I’ve pulled a few ECUs from auto XJs that I don’t need. Where do you live?

[mark corbitt]

I'm in Lakeland Ga. 31635

[87MJTIM]

You need #5428 for an automatic 

[eaglescout526]

7 hours ago, mark corbitt said:

I have an 87 4,0 4x4  and  according to build sheet an 5-45RFE automatic transmission, which ECU should I upgrade to?

Ok hang on. I don't know if it was stated before but the build sheets from pre ‘89 are not incredibly accurate. You should have a 4speed AW4 automatic trans. 

[cruiser54]

428  is the most common one IIRC and is for an auto trans. Works well in either application

 

 

[mark corbitt]

12 hours ago, cruiser54 said:

428  is the most common one IIRC and is for an auto trans. Works well in either application

 

 

thank you.

[Mattkh]

On 9/17/2019 at 7:56 AM, mark corbitt said:

I'm in Lakeland Ga. 31635

Hey me too! Thought I was the only one in South Georgia on here 

[mark corbitt]

1 hour ago, Mattkh said:

Hey me too! Thought I was the only one in South Georgia on here 

Nope.