junkyard shopping for new 4.0

[lankchevy]

don-so u used the 93 head, and bolted your 88 intake manifold to it? will i be able to use the new header style exhast manifold or will i have to reuse my old one?

kolby

 

[jneary]

if the junk yard is delivering this engine. make sure everything that is on your original block will bolt up to corresponding locations on the zj block. for some reason i think i recall recieving a zj engine for an xj and something wouldnt work. i cant remember all the details.

 

[lankchevy]

hmm my dad is picking the engine up for me tommarow while im at work, but we know the people fairly well that own it so if there is a problem we will be able to work something out.

kolby

 

[4xBob]

Two things come to mind in combining HO and Renix era parts: the head/intake/etc bolt up fine, but the two computer systems use different TPSs. An HO type TPS reportedly doesn't work for a Renix ECU (computer). Somewhere there was a post about using the pre-HO TPS on the HO Throttle Body, by rigging some mounting or positioning parts....then everything worked with the ECU fine. The other issue is power steering pump mounting is different between the non-HO and HO versions. Grab the pump mount with the new block........haven't had to do this yet, anybody have more details? And you know that the non-HO temp sensor for the aux fan is in the radiator tank, while on the HO it is built into the water neck (so keep your old water neck, or be ready to put a threaded plug in the HO water neck).

 

[Don Becker]

As I indicated in my original post here, I didn't do the switch myself . . . 'paid to have it done by my mechanic. But, I kept tabs on the job and it certainly was my understanding that they ran into no difficulties (other than it just being a nasty job) . . . the '93 HO 4.0L was out of an XJ . . . . EVERYTHING from the '88 was used EXCEPT for the long block (block, head, valve cover, oil pan, timing chain/cover, etc) . . . I don't know how to be more clear . . . if I try to list all of the accessories that were transferred from the '88 to the '93 long block, I'll surely omit something and cause more controversy . . . 'hope that helps. Don

 

[lankchevy]

k i got the engine home the other day, and ive almost got all my old accesorys on it now. so far so good, as far as i can tell they are they same block and head. i reused my 88 oil pan, dist., intake, motor mounts,water pump, and all my accessorys, the motor had a boss in it for the knock sensor, should have the new motor in tonight and hopefully all hooked back up and running tommarow. by the way how does a knock sensor work and what exaclty does the stupid little thing do anyway?

kolby

 

[jneary]

the knock sensor senses engine ping, and sends the info and the pcm retards the timing until it stops.

 

[lankchevy]

hmm thats interesting, well we got the engine in today, and running, its running real rough tho soo i dont know what the problem is, prolly didnt plug in a sensor or a vaccum problem. its still driveable just ruff.

kolby