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-   -   4.0 throttle body upgrade compatable??? (

Captainrichhill 03-15-2012 10:31 AM

4.0 throttle body upgrade compatable???
I have a 1990 YJ with the enimic 2.5l. I've been reading about the 4.0 TB upgrade and what I can tell is that if you have the 4 bolt intake then you can upgrade, if you have the 3 bolt intake then you can't.

Here's the skinny, I just looked at mine and it looks like it has 4 bolts but they are not symetrical spacing. They don't look like the hole will line up on the 4.0 TB's that i've seen for sale.

o o 0 0

0 0 0 0

My TB pattern 4.0 TB pattern

Any ideas if I would be able to make the swap???


Tyewilly 03-15-2012 12:00 PM

The 4.0 throttle body will fit '91+ 2.5s with mpi, unfortunately it won't fit '87 - '90 2.5s with tbi.

Xpress 03-15-2012 02:01 PM

Yes, unfortunately you have a TBI model. The 4.0 throttle body was made for MPFI intakes, not your single injector style.

Remove the intake pipe from the throttle body. If there is a big injector inside, the 4.0 swap won't work.

Captainrichhill 03-15-2012 06:16 PM

Thanks : (

cvdenson 03-17-2012 08:09 PM

You could try this out: Leigh Performance Machine

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