Need quick advise on a motor swap -
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Unread 10-31-2013, 01:02 AM   #1
Registered User
1987 YJ Wrangler 
Join Date: Apr 2009
Location: sierra vista
Posts: 48
Need quick advise on a motor swap

Sup buddies need some advise from the jeep experts on here. I can get a complete 89 xj with a 159000 miles on it for 500 bucks question is would this be a good candidate for a swap into my 87 yj. My yj factory harness has been hacked to all hell and I have a ax15 5 speed in my yj currently . Can you is sootmeyour thoughts good or bad and any issues I may have please.

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Unread 10-31-2013, 02:40 AM   #2
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1995 YJ Wrangler 
Join Date: Nov 2009
Location: Schenectady, New York
Posts: 1,184
I know some will probably tell you to hold out for a 91+ which will be the HO with the MOPAR computer, but I'd say if it runs well and doesn't smoke, go for it

the 87-90 4.0s in XJs had the RENIX computer (Renault/Bendix collaboration). some people bad-mouth it, but I personally liked them. I had an 87 XJ and that thing was a beast. easily the most reliable motor I've had in a vehicle (so far anyway). Some will point out that the 91+ with the "HO" designation has more horsepower. in reality, the HP difference between the 2 is minimal... the 87-90 were rated right around 175 and the 91+ around 190hp.... but what they fail to mention (either because they aren't aware or they just choose to omit it to make their HP argument more valid) is WHERE the HP and torque peak is achieved...

1987-90: 177 hp at 4500 rpm and 224 lb·ft at 2500 rpm
1991-95: 190 hp at 4750 rpm and 225 lb·ft at 4000 rpm

so while HP peaks pretty much the same RPM, torque for the 87-90, at only 1 lb-ft less comes in at a much more usable location for street and off-road use

my 87 had about 350,000 miles when I got rid of it about 12 years ago due to uni-frame rot... sold it to a guy who pulled the motor to swap into his XJ and last I heard about 5-6 years ago the motor was still going strong
[FONT="Comic Sans MS"][COLOR="Blue"]Sean B. - Schenectady, NY - 95 YJ, 350/700r4/NP241, JB Shorty SYE, 8.8 rear, 2" BDS, 1" homebrew shackles, Daystar 1" BL, TJ flares, 35x12.50 General Grabber AT2 on 15x10 Bart D-Truckers, Polyshield polycarbonate windshield, HD over/under crossover steering
[/COLOR] [COLOR="Red"]swap/build thread: [url][/url][/COLOR][/FONT]
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Unread 10-31-2013, 07:36 AM   #3
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1989 YJ Wrangler 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,013
Absolutely get it! That is cheap! The swap is so similar the renix just requires adjustments. The Cherokee Renix is even multiport unlike the 2.5! Not only yes, but hell yes. You need 2 High pressure fuel lines all the way to the front and a gas tank and skid plate from a 91-95 YJ.
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Unread 10-31-2013, 10:12 AM   #4
Registered User
1987 YJ Wrangler 
Join Date: Apr 2009
Location: sierra vista
Posts: 48
Sweet I think I am gonna pull the trigger and buy it I just went and looked at it and the thing purrs like a kitten . I'll be hitting the forum up for more advise on the swap as I get started thx against guys
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