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engine swap, now many issues.

The1AndOnlyBug

NAXJA Forum User
Location
Denver, Co
Ok so here we go, I have owned 3 YJ's with my last one in Colorado springs/Denver and built just too small for carnage canyon, so I'm very familiar with jeeps and 4.0's.



I bought my wife a '01 XJ and 6 months later the engine blew, still ran but really bad knock, no power, oil in the coolant and overheats after 5 minutes. So I found a new engine. $800, Fresh rebuild, 0 miles, unfortunately it was from a '02 wrangler, doesn't fit. So I find another engine, $500 it is from an 87-90 Comanche bored 30 over and about 60-70k on it.



I removed the bad engine got everything bolted up to the MJ engine (after porting my horseshoe intake to match the head, along with adding a header, and a heavy duty transmission cooler.) got the engine installed in this nightmare of a vehicle (I miss the room I had in my YJ's) and started it right up.



Well it idles fine, but upon startup there is a horrible screeching from the front of the engine that lasts 2-3 secs, my headers are glowing red, I've got a header leak ( may explain the glowing, running too lean) I had to ground bus pin 4 to get the scanner to work (triple checked all grounds with a multi metre), and I'm throwing a handful of codes.... P0700 P1687 P1698. I can read all sensors while the vehicle is running so if someone tells me the perimeters then i can tell you what its reading.


Biggest issue is I have less that 24 hours to have this vehicle fixed, I am supposed to be picking up a uhaul trailer and moving from VA to ME tomorrow....... if I was still in CO I could have a wrenching party with several jeepers, but out here in va.... My options are limited.


If it makes any difference a couple times when I reved it up it backfired through the intake.
 
Last edited:
Squealing

https://drive.google.com/file/d/0ByWsreJoySKUOUQ0NmhVS3dDWG8/view?usp=drivesdk


What the header looked like last night
https://drive.google.com/file/d/1RFK4iQLI19lkuq7-Bmf5Mz02Tm1PdtWxXA/view?usp=drivesdk

view
 
00/01 had a weak head casting. Easiest thing would have been take the head from the 02.

The 87-90 is totally different engine management. Did you reuse your 01 sensors and throttle body and injectors, or keep the ones that were on it? You need to use your originals so the computer gets expected data.
 
I swapped every sensor over to the older engine. While I was tempted to take to head from the '02 engine, my sister's '00 TJ has a lot of engine rattle (over 200k on the jeep), so the engine from the '02 Is going in my sister's jeep.
 
Well it's fixed, it took me 4 hours just to remove the header, I did not put it back on. I put back on the stock exhaust manifold (that I had port matched to this block) to be on the safe side I took both gaskets and put a coating of fiberglass stove gasket cement between them and then put it all back together. I have no leaks and am only throwing the one code the jeep was throwing before the engine blew p0455 (evaporative emmision leak monitor large leak) it's not the gas cap or the connection to the intake.
I also added another ground strap from g105 I think? to another spot on the block, I also noticed that I had my block to body ground strap attached to a valve cover bolt, I moved it where it goes, attached to the d/s rear head bolt.
 
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