motor swap

[egotripp]

I have a 91 YJ and a 98 XJ. The 4.0 in the YJ has been rebuilt with performance parts and is bored .030 over. I would like to swap this motor into my 98 XJ since it will be gettin a chevy 350 eventually. Since it is basically the same motor, is it a direct swap? What i'm rally intrested in is will the electronics for the 98 run the 91 motor or do injector systems need to be swapped as well?

 

[rooneypower]

:dunno:





I have no clue

Keil

 

[Rasty1]

I would recommend you check with the Florida Dept of Motor vehicles first. I doubt that they will let you swap an older engine into a newer vehicle.

That is the rule here in California.

 

[ktwalker01]

Florida doesnt have check ups on cars. You register the car and pay insurance that is it.

 

[Overdriven]

I would swap over just the short block or even the block and head. Use your current exhaust and Intake. The 91 is a OBD1 and the 98 is OBD2. You want to keep all your sensors from the 98 engine on the 91 when you run it.
I'm swapping a 96 engine into my 89 and sticking with my renix sensors.

Good luck.

 

[proskier101]

I would recommend you check with the Florida Dept of Motor vehicles first. I doubt that they will let you swap an older engine into a newer vehicle.

That is the rule here in California.

the rest of the country doesnt like the trees..

in FL my bumper height is 10" higher than legal, tires are about 8" outside of the jeep fenders, upgraded exhaust, and a "cold air intake"(might be illegal in CA)


but our wheeling sucks.

 

[egotripp]

I think as long as we're not driving over the gators, Florida doesn't really care. But when I do return back to Texas the OBD2 will come into play since emission testing is done in the Houston area.

 

[Georgia Mike]

I'm doing the same thing, only backwards. I'm putting a '96 into a '91. As far as the engine is concerned, use the injectors, fuel rail, throttle body, & the distributor from the OBD-II engine and swap the correct sensors onto the older engine, and all should be good.

 

[sjkimmel99]

Don't forget to look at the water pumps. The WP on the XJ turns in the reverse direction from the engine (which is why the pully is flat & not grooved.) If the YJ water pump is driven by a grooved pulley it means it turns with the engine and you'll want to swap the XJ water pump over or, if you've never changed it, get a new XJ waterpump.

maintaing the stock fan location is another reason to just do the long block and maybe head and keep all the XJ bracketry.

Unless you just swap the YJ fan as well but I don't think I'd do it that way.