4.2L Fuel Injection and Build - Page 11 - JeepForum.com

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post #151 of 612 Old 08-04-2011, 06:48 PM
flyin8s234
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1984 CJ7 
 
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She's alive!!! and boy was she loud (just the header). got her to the muffler shop today and now she's nice and quite - i was tired of having a loud jeep.

turns out i had the fuel lines hooked up wrong; i had the return contacted to the fuel pump. as you can imagine that didn't work out very well. fixed that and now you can't get me out of the drivers seat!

I love this jeep now! before i loved it but was trying to sell it for its lack of reliability, now I'm gonna driver her for the rest of my life. Best thing i could have done for my jeep for about 1200$ (and thats without selling my parts jeep for scrap and my old 258 head)

Thankyou cevans87!!! without that phone call id still be trying to figure out where the wiring goes.

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post #152 of 612 Old 08-09-2011, 10:41 AM
motormike86
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Quick question: I'm picking up a 94 Grand Cherokee as a donor vehicle for the mpfi swap, everywhere I've read says use the xj head but the zj has the same #7120 casting. Will the zj setup work or do I need a xj to do the swap?
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post #153 of 612 Old 08-09-2011, 10:22 PM Thread Starter
cevans87
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the zj head is the same, but i know that some of the grand cherokee's had different motor mount setups...

here are pictures of the cherokee mounts and the grand cherokee mounts...

the 1st one is cherokee/wrangler and the second is grand cherokee

that may be your only problem, and as far as i know they bolt up differently to the motor as well, so the block may not work for you, but the head will surely fit...

word to wise... when looking for parts ** NEVER USE A GRAND CHEROKEE AS A DONOR**
things are a lot different, the motor harness, the motor mounts and several others... about the only thing i would get off a grand cherokee is a 136amp alternator, and disc brakes
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Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto

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post #154 of 612 Old 08-10-2011, 07:07 AM
motormike86
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I see, I'm planing on keeping the 4.2 block and installing the 4.0 head along with fuel injection. Great write up btw!
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post #155 of 612 Old 08-17-2011, 09:54 AM
lclark2074
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Quote:
Originally Posted by motormike86 View Post
Quick question: I'm picking up a 94 Grand Cherokee as a donor vehicle for the mpfi swap, everywhere I've read says use the xj head but the zj has the same #7120 casting. Will the zj setup work or do I need a xj to do the swap?
The only problem with a grand cherokee is security on the computer
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post #156 of 612 Old 08-17-2011, 11:06 AM
remmons
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Originally Posted by lclark2074 View Post
The only problem with a grand cherokee is security on the computer
I cannot vouch for the GC, but on the XJ, all you have to do is twist the white and purple twisted pair together near the PCM. This will fool the PCM into thinking that the Security system is intact. This is what I had to do to my Basket Case, which is what I have been driving to work all this week.

Robert.

2015 Cherokee Trailhawk V6.
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post #157 of 612 Old 09-01-2011, 05:31 PM Thread Starter
cevans87
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hey remmons, glad to see you finally got it running...

iclark... that's not the only difference, please stay off my thread if your going to keep giving incorrect information...

Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto

I Am The Jeep Surgeon!!!
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post #158 of 612 Old 09-01-2011, 05:40 PM Thread Starter
cevans87
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So, Tommrow I will be starting the AW4 swap.

I have the AW4 and NP231J already connected, cleaned and painted and ready to go in, I will be picking up the torque converter tommrow (might as well get a new one while the tranny it out)

I will be using both XJ shifters, xj cables, and xj harness... the reason I will be doing this is because my wiring harness on my 4.7 is already out of a xj with odb1.

So unless something comes up that I don't know about...

I will then drop the skid plate, and remove both drive shafts...

I will be dropping my ax-15, leaving in the clutch pedal, master cylinder, and clutch fluid line going to the tranny (all for further use if i want to switch back).

Then I will take the clutch, pressure plate and flywheel off, and attach my flexplate.

Then I will raise the aw4 into position and BFH the skidplate till she fits...

Once in, I will bolt her down, and connect the driveshafts.

The I will install the tranny cooler, and temp guage.

Connect all electrical connections, and fill with fluid.

I will then go and install the shifters, connect linkage...

Then I will attempt and trial run...

Since the harness is already out of a cherokee, the connections are the same on the tranny and the harness...

I already have the wiring ran for the TCU and the TCU mounted under the dash...

So it should be a pretty straight forward swap... no electrical confusion, no missing parts... Just unbolt drop and rebolt... I like it !!!

Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto

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post #159 of 612 Old 09-02-2011, 09:28 AM
remmons
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Quote:
Then I will raise the aw4 into position and BFH the skidplate till she fits...
I did this to my skid plate, then I read on here somewhere that you can redrill the flange to reclock the transfer case and bring it up about ten degrees. This will also help to clear the skid plate. It is easy to do. Take yourself something to make an impression, like a sheet of paper, of the flange. Then transfer the template to the new position and mark off the new bolt hole locations. Then steadily drill out the new bolt holes on the flange. But a little warning, if you reuse the steel bracket that suspends the transfer case linkage, it will no longer line up with the new holes. You will have to modify the bracket accordingly to make it useful again. I found this out the hard way when I performed this operation and got it all back in my Jeep.

Otherwise, you sound like that you are doing well. Good luck!

Robert.

2015 Cherokee Trailhawk V6.
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post #160 of 612 Old 09-02-2011, 11:04 AM
Kman1983
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COOL!! I'm very interested in following your AW4 swap. I have an AW4 and XJ harnes out of a '95 and was thinking about using it in one of my wifes YJ's that currently has a 999 and carbed 258.

Rolled Red Jeep Club Member #258
'83 CJ5, 4.0 MPFI swap, T18/D20, CenterForce II clutch, Dana44/30(73 CJ5) with 3.73's,'79 knuckles and 11" discs, sagged 4" lift, 2" BL, 34x9.50x15 Super Swamper Pizza Cutters

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post #161 of 612 Old 09-04-2011, 03:41 PM
94chb
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ive got a few questions, really interested in doing this swap cause as you know carbs really suck when trying to rock crawl. i have a 89 wrangler 4.2 with a auto trans what all will i need to swap to mpfi and also would like to keep the auto. any input would be greatly appreciated. just give me a list of everything you think i will need to make the swap work. so i can start lookin.
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post #162 of 612 Old 09-04-2011, 04:13 PM Thread Starter
cevans87
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Quote:
Originally Posted by 94chb View Post
ive got a few questions, really interested in doing this swap cause as you know carbs really suck when trying to rock crawl. i have a 89 wrangler 4.2 with a auto trans what all will i need to swap to mpfi and also would like to keep the auto. any input would be greatly appreciated. just give me a list of everything you think i will need to make the swap work. so i can start lookin.
you will need to get the following

91-95 4.0L Head from cherokee
91-95 complete wiring harness (under hood and going to the tranny and xcase) from cherokee
Vehicle Speed Sensor for a 91 YJ
4.0L Flywheel (91-95)
91-95 ECM from cherokee and same jeep you pulled harness off of
Crankshaft Position Sensor From a 4.0L (91-95)
Distributor from a 4.0L (91-95)
Intake and Exhaust from a 4.0L Exhaust (91-95) Intake (91-2006)
Throttle Body and Injectors from a 4.0L (91-95)
Fuel Pump Part Number SP736H from Advance Auto (this is the complete unit, pump, hanger, and sending unit)

Theres a few other things but there small and you will probably have them laying around anyways...

You can keep your auto, you only need to change out the flywheel...

Also as far as the wiring goes... leave your old harness in and lay the new one on top and just connect what you need to run the fuel injection, this will leave everything else the way it left from the factory, gauges will still work, ignition and so on... you only need 5 wires to run the fuel injection....

Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto

I Am The Jeep Surgeon!!!
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post #163 of 612 Old 09-04-2011, 05:24 PM
94chb
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ok thanks and what about the cps i havent looked on my trans if there is a spot for it.
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post #164 of 612 Old 09-04-2011, 05:50 PM Thread Starter
cevans87
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You will have to check, if not you dont need to change the flywheel and the swap will be a lot easier and faster because you dont have to take the motor or tranny out to change the flywheel... You can get the cps relocation kit from hesco... It moves the sensor from the bellhousing the harmonic balancer... Its about $260 though.... It works, i had one on my 88 yj

Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto

I Am The Jeep Surgeon!!!
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post #165 of 612 Old 09-04-2011, 05:55 PM Thread Starter
cevans87
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http://www.hesco.us/shop.asp?action=...640&catId=7902

If you have v belts

http://www.hesco.us/shop.asp?action=...641&catId=7902

If you have serp belts

Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto

I Am The Jeep Surgeon!!!
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