H.O. swap into a 90 chassis HELP!!!

lorax81

NAXJA Forum User
I just picked up a motor trans and t-case off craigslist. the motor is out of 95 and thus is an h.o. i am putting it into my 90. the motor came with all the wireing harnesses, computers, fuse panels, etc. my question is what can i delete from my 90 so i can paint and make room help

thanks j
 
If you want to just drop it in, I *believe* everything from the renix can be dropped onto the H.O. longblock with the possible exception of the knock/predet sensor. Hopefully someone with more experience can say for sure - in the meantime, search for "naxja renix ho 4.0 swap" on google.
 
Well, are you planning on it being a Renix system or a OBDI system?

It sounds like you are thinking OBDI, and if so then you've got your work cut out for you. Make sure you have good wiring diagrams for both years if you are planning on hacking the OBDI engine management system into the Renix harness.

Pretty much the only thing you will be eliminating is the EGR system. In fact, you will need the OBDI evap purge solenoid and probably the evap canister too.
 
I went renix its way way way easier then tryin to adapt the obdi into the renix to tell u the truth i dont think i could do it unless i had the other rig nose to nose with ol'blew so i could swap every wire and know where it came from.

but all is well the motor is bolted up tight most all the wiring is all hooked back up. tamara i will finish the motor and make sure everything runs correctly. then its back to welding up the floor pans and buildin the cage once i can locate some cheap steal. ill try to get some pics up if i can figure it out.
 
Everything from your renix motor will swap straight to the HO block. IE- intake and exhaust manifold, all sensors. If you keep it a renix you will save yourself a headache. I just did this yesterday. Oh yeah and the distributor has to go as well as Flywheel.
 
i have to use the old flywheel whats the difference in flywheels both are autos

the renix and HO use a different cps. the cps reads the notches on the flywheel to adjust timing, so a renix cps needs to read a renix flexplate/flywheel and visa versa.
 
Hey guys, I'm new here. But I'm going to be doing the same swap, and want to know about the knock sensor. Can I get any year of h.o and do the swap and not have to worry about the sensor. I want this to be as painless as possible. Thanks for any help.
 
If swapping everything to OBDI, you will need to have a flexplate from an OBDI aw4, due to the CPS, it will not even start without the flexplate/CPS that match the ECU being used.

Also, the is no knock sensor on any HO or later 4.0s, so it is not even an option to have a knock sensor if OBDI electronics are going to be used. If the HO motor is adapted to Renix electronics(as with most Renix/HO swaps you will see on here), the knock sensor is not absolutely necessary for to motor to operate. Early HO blocks did have a hole for the knock sensor, but this hole was not tapped in most cases. While it is ideal to drip/tap a hole for the sensor in a Renix conversion, it is not required for the engine to run. I run 87 electronics on a 93 motor, and my knock sensor is plugged in, yet not screwed into the block.
 
i swapped out the flexplate, dist., pow ster., intake, alt., tail cone on the transfercase, fuel rail 4 times. all new vac hoses. it will crank over i get spark to the plugs and fuel to the rail but no fire. i just cant seem to figure this out any one have any ideas please

the renix to renix only took day this is been going on a week its makin me koo koo krazy
 
i swapped out the flexplate, dist., pow ster., intake, alt., tail cone on the transfercase, fuel rail 4 times. all new vac hoses. it will crank over i get spark to the plugs and fuel to the rail but no fire. i just cant seem to figure this out any one have any ideas please

the renix to renix only took day this is been going on a week its makin me koo koo krazy

spark, fuel, timing, compression equals vroom vroom.

1.spark, are you getting a hard snapping blue spark?

2.fuel, what are the actual fuel pressure readings?

3.timing, is controlled by the ecu. as long as the cps is good and the renix flexplate is used and the dizzy is indexed proporly, timing should be close enough to start.

4. compression?

common oversight is not connecting the ground strap from the head to firewall after swap. the ecu and sensors must have a good ground curcuit.
 
im about to go get a spinal injection this afternoon so i dont know how with it i will be after 25 mg of valium but i will at least go up there and look at it maybe if i look at it hard enough it will start

j
 
Sorry to bug you guys, while trying to help some one else. Can you guys tell exactly what it takes to swap the ho to a renix system. I have the motor all lined up and want to do this swap. But I just want to make sure I can do it. Thank you for the help.
 
Sorry to bug you guys, while trying to help some one else. Can you guys tell exactly what it takes to swap the ho to a renix system. I have the motor all lined up and want to do this swap. But I just want to make sure I can do it. Thank you for the help.

Just keep everything from the Renix, including all sensors, harness, flexplate/flywheel, everything.

One bone of contention may be mounting the knock sensor. Early HO blocks have the knock sensor boss in the block, but it isn't threaded, so you can use a tap and good to go. Late blocks do not have the boss. You can just hook up the knock sensor and leave it unmounted, tied up so it doesn't get into trouble, and you will never know the difference.

If you get a late model engine w/o the temperature gauge/light sender in the rear of the head on the DS you can just put a late model thermostat housing in with a sender port.
 
the renix components i am using off of my 90 are; intake(and everything that was on it), exhaust, dist, flywheel, brand new crank sensor, alt, pow ster pump, coil, and tail housing on the transfer case.

basically u strip the block down to the water pump and put all the old renix stuff on

with that said i still cannot get mine to fire

fuel press is 39 w/vac 32 wo/vac
compression is in the mid 120's all cylinders
i have strong spark at TDC on all cylinders


yet i still cannot get it to fire PLEASE i know it has to be somthing simple but what

J
 
Well, 120 in each cylinder, you have a strong blue spark at all cylinders, and you have fuel pressure that is correct.

So, even though you have fuel pressure, is the ECU firing the injectors? Grab a NOID light and check for injector firing--test lights and multimeters won't do it. Or, you can spray ether into the intake and if it fires you will know it is the fuel injection.

Those grounds at the dipstick tube are CRITICAL. They are the grounds for the ignition control module, the ECU, and the 02 sensor.

The synch sensor in the distributor sends signals to the ECU along with the CPS/CKP that will determine the firing duration of the injectors.

Those are a few ideas for things to check.

Just to stress something simple, being 180 out on the timing has caused many XJ owners to rip out large patches of their hair. When you say firing at TDC--that is TDC on the compression stroke, i.e., the stroke where both valves are closed and if the spark plug is out there is a great force of air from the cylinder?

Not a dis, it has happened to others so I gotta ask.
 
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