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Unread 07-11-2008, 02:00 AM   #1
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Join Date: Jul 2008
Location: terryville ct
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4.0 swap wiring

1st post on this forum. and this is prolly covered many places elsewhere, but ive done my 4.0 swap, and its wire time. ive run into an odd problem. theres dozens of good sites about this swap, but everyone seems to favor an xj swap into a yj. ive got an 87 yj. and i swapped in a 4.0 from a 91 YJ. so i did a yj/yj swap. the best i can figure is the chassis harness is the same from 97-91. and since this is a 91 engine i SHOULD in theroy be ok. i just need to plug the fuel pump power wire into the bulkhead connector. and splice in my gauges. im hoping soneone here has done this, and can give me a lil insight. thanks .

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Unread 07-11-2008, 02:31 AM   #2
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Join Date: Apr 2008
Location: Miami, FL
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Did you previously have a 4.2 or a 2.5 in the jeep? I'm pretty sure the 87 - 90 yjs were 4.2 liter and the wiring harnesses should be the same. Its in 91 that they changed everything over to 4.0. I doubt that the fuel pump is the same

Last edited by Jkanly; 07-11-2008 at 02:44 AM..
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