worknprogress90

Ok so i have a early 90s 4.0 and its weak. i was thinkin of swap the intake out for a newer 2000 model but are the fuel rail injector holes in the same locstion because the 90 has a return line and 2000 doesnt wat do i do

okcjeeper

I don't think the 99+ intake mode will work on non HO motors at all. exhaust setup is completely different along with the fuel rail. I could be wrong so maybe someone who knows more about RENIX will chime in.

91familyxj

Im not really sure but I have an 88 block and head in my 91( ya I know its a non HO but it runs). But I have my 91 intake and exhaust on it. Im not to sure but I think you Still have to use your fuelrail. But someone else chime in and correct me.

CheapCherokee

yea i dont think it'll work because the injectors are different and the RENIX has a different throttle body than the H.O.s

worknprogress90

will the ford 4 hole injectors still work with the manifold cuz i have a couple different sets of them?

JJaycXj

well actually if yours is early 90's then it is not a renix. so it is an HO

worknprogress90

build date like 10/1989 so how do i tell if its the ho or not?

ckysodkorn_xj

run the vins?

JJaycXj

yeah it is a renix then anything buit in 1990 and up is ho

worknprogress90

ok wat can i do to get more power other a complete tear down

91familyxj

O ya I forgot. I bet you have a TB with only 3 mounting bolts. Ya wouldnt work. I would start but a tune up change everthing out and clean it up. You could bore out your TB I belive, CAI, Just get more air in and more back out with a free flowing exhaust. Something like a header to a high flow cat then a whatever muffler you like (to many opinions here. lol)

littleredXJ

They made renix engines in 1990...

worknprogress90

no loud mufflers u cant sneak around while hunting with one where can i buy the throttle plate by its self so i can bore it out will the for injectors work

n_csmith

from what i understand from a long time jeep cherokee buddy of mine..there is really nothing you can do to pull more power out of the 4.0 if its not an HO, his father has an 89 and we swapped his intake throttlebody spacer and header onto it and it do a darn thing, but on his 95 HO it seriously increases his power. BUT if that is wrong please correct me because i am currently in the process of tearing down and cleaning an 89...my head was disgustingly covered in what i am assuming was old oil and crap..the block is clean, but the lifters are bad and some of the oil passages are pretty clogged so i need to get it all clean. SO i will be keeping my eye on the thread cause i am going to need things to pull more power as well.