need some help on my 4.0 head swap! - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > need some help on my 4.0 head swap!

JK Front Lower Adjustable Control Arms!QTP Low Profile Cutouts Now @ MarylandSpeed- Free ShippingOPTIC ARMOR WINDOWS all sale now !!!!!!!!

Reply
Unread 02-17-2010, 09:57 AM   #1
orichierich
Registered User
1990 YJ Wrangler 
 
Join Date: Feb 2009
Location: Corona CA.
Posts: 27
need some help on my 4.0 head swap!

I have a couple of questions for the swap experts: (1990 yj 4.2 with a 1993 xj head and wiring harness)

1. I have swapped the head, done 60% of the wiring, and I used the donor coil and distributor, so the wiring for the alternator is now for the 4.0. How do I make the 4.0 alternator fit with the 4.2 bracket or what alternator can I get that will fit with the 4.2 bracket and still use the 4.0 wiring?

2. I would prefer to use the in tank fuel pump and sending unit, I have looked and my gas tank has a round opening on the top and the 91+ wranglers have the rectangular opening, has anyone or is there a way to adapt the 91+ pump and sending unit to work in my tank? I have seen a few modifications to cj tanks online where they opened up the hole a bit to fit the gm pump and sending unit in. so I was wondering if anyone has done what I want to do.

Thank you in advance.

Richie-

__________________
STOCK JEEPS (used to) RULE!!!!!!!!!
[QUOTE=RikRotorhead]Why.... some of my best friends have round headlights.[/QUOTE]
[QUOTE=Jeebs;9478201]Dang! I guess thats why they're affectionately called ProCrap![/QUOTE]

Last edited by orichierich; 02-17-2010 at 10:39 AM..
orichierich is offline   Reply With Quote
Unread 02-17-2010, 10:54 AM   #2
wendell
Registered User
1987 YJ Wrangler 
 
Join Date: Aug 2006
Location: grafton ohio
Posts: 3,289
I can't really help you, but to avoid those kinds of problems. I swapped on the 4.0 head and went with the offy intake and holley 4 barrel setup. The holley TA 4 barrels are built for off road and will take some extreme angles. Also there's no computer or sensors to worry about. I've found this setup to be reliable and capable, easy to maintain. I known it's too late to go back. Some one will be a long to give you some advice. Good luck with it.
__________________
1987 wrangler, 258 I-6, 5-speed.
2007 liberty sport 4X4, automatic
2009 ford ranger 4x4 FX4 OFF/ROAD, 5-speed
wendell is offline   Reply With Quote
Unread 02-17-2010, 11:05 AM   #3
DivineKaos
Registered User
2000 TJ Wrangler 
 
Join Date: Jul 2009
Location: Saint John, New Brunswick
Posts: 485
Quote:
Originally Posted by orichierich View Post
I have a couple of questions for the swap experts: (1990 yj 4.2 with a 1993 xj head and wiring harness)

1. I have swapped the head, done 60% of the wiring, and I used the donor coil and distributor, so the wiring for the alternator is now for the 4.0. How do I make the 4.0 alternator fit with the 4.2 bracket or what alternator can I get that will fit with the 4.2 bracket and still use the 4.0 wiring?

A 4.0 or 2.5 alternator should line up perfect!

2. I would prefer to use the in tank fuel pump and sending unit, I have looked and my gas tank has a round opening on the top and the 91+ wranglers have the rectangular opening, has anyone or is there a way to adapt the 91+ pump and sending unit to work in my tank? I have seen a few modifications to cj tanks online where they opened up the hole a bit to fit the gm pump and sending unit in. so I was wondering if anyone has done what I want to do.

I know you want to use an in tank, but I have no experience with that. I simply bought an inline pump and mounted it to the inside of the frame, and am making a 5/16 skid plate just to be safe.

Thank you in advance.
Hope this helps
__________________
"A man has to know two things in life, limitations and priorities. You let your priorities get in the way of your limitations." - MrBlaine
DivineKaos is offline   Reply With Quote
Unread 02-17-2010, 11:19 AM   #4
orichierich
Registered User
1990 YJ Wrangler 
 
Join Date: Feb 2009
Location: Corona CA.
Posts: 27
Im going to give the alternator another shot. I had modified the bracket to fit the 4.0 alt in, but now its way out of line with the other pullys.

also what inline fuel pump did you buy and use?

thank you both for the answers.
__________________
STOCK JEEPS (used to) RULE!!!!!!!!!
[QUOTE=RikRotorhead]Why.... some of my best friends have round headlights.[/QUOTE]
[QUOTE=Jeebs;9478201]Dang! I guess thats why they're affectionately called ProCrap![/QUOTE]
orichierich is offline   Reply With Quote
Unread 02-17-2010, 11:20 AM   #5
RikRotorhead
Web Wheeler
 
RikRotorhead's Avatar
1988 YJ Wrangler 
 
Join Date: Aug 2008
Location: SloCal
Posts: 8,830
The 4.0 alternator has to be used because the computer controls the voltage regulator on the 4.0, as opposed to the 4.2 alternator having the internal regulator.
However, the bracket is the issue. The mount for the 4.0 where it connects to the block is different than on the 4.2 mount. Using the 4.0 bracket will not line up on the 4.2 block.
__________________
Betcha' wish your girlfriend was as dirty as my Jeep!
Zombies hate fast food.
Hang on! This is gunna' be a thrill ride of geriatric proportion!
RJC#512
RikRotorhead is offline   Reply With Quote
Unread 02-17-2010, 11:28 AM   #6
DivineKaos
Registered User
2000 TJ Wrangler 
 
Join Date: Jul 2009
Location: Saint John, New Brunswick
Posts: 485
Quote:
Originally Posted by orichierich View Post
Im going to give the alternator another shot. I had modified the bracket to fit the 4.0 alt in, but now its way out of line with the other pullys.

also what inline fuel pump did you buy and use?

thank you both for the answers.
I purchased a 25-40psi pump from Princess Auto for $138. It was the only style they stock that I could find.

We used the 4.0 bracket and it lined up..my donor vehicle was an 89 Cherokee Limited. Maybe it was a bit different?
__________________
"A man has to know two things in life, limitations and priorities. You let your priorities get in the way of your limitations." - MrBlaine
DivineKaos is offline   Reply With Quote
Unread 02-17-2010, 11:32 AM   #7
RikRotorhead
Web Wheeler
 
RikRotorhead's Avatar
1988 YJ Wrangler 
 
Join Date: Aug 2008
Location: SloCal
Posts: 8,830
Quote:
Originally Posted by DivineKaos View Post

We used the 4.0 bracket and it lined up..my donor vehicle was an 89 Cherokee Limited. Maybe it was a bit different?

Interesting. Could there be a difference in the block on the earlier Cherokees?
Or maybe the bracket is different on the 89 than the 93 donor vehicle Richie is using.
Maybe a trip to the bone yard is on the schedule eh?
__________________
Betcha' wish your girlfriend was as dirty as my Jeep!
Zombies hate fast food.
Hang on! This is gunna' be a thrill ride of geriatric proportion!
RJC#512
RikRotorhead is offline   Reply With Quote
Unread 02-17-2010, 11:36 AM   #8
DivineKaos
Registered User
2000 TJ Wrangler 
 
Join Date: Jul 2009
Location: Saint John, New Brunswick
Posts: 485
Quote:
Originally Posted by RikRotorhead View Post
Interesting. Could there be a difference in the block on the earlier Cherokees?
Or maybe the bracket is different on the 89 than the 93 donor vehicle Richie is using.
Maybe a trip to the bone yard is on the schedule eh?
It could be. The Cherokee was a bit different all around, for instance- it is an 89, yet had multi port fuel injection, yet didn't have the 7120 high output head. MPFI wasn't even an option you could get at the time.

It was a one owner vehicle, that they had bought brand new- and they said they had never done anything to it.

Wish I could help more.
__________________
"A man has to know two things in life, limitations and priorities. You let your priorities get in the way of your limitations." - MrBlaine
DivineKaos is offline   Reply With Quote
Unread 02-17-2010, 09:56 PM   #9
orichierich
Registered User
1990 YJ Wrangler 
 
Join Date: Feb 2009
Location: Corona CA.
Posts: 27
Thank you all for your help, I will search for a 89 bracket and see if that will work, and I called my autozone and they dont carry any of the high output fuel pumps the highest output they had was 9-12psi, I have heard of people using the es2000 and the walbro 255, I was hoping to find a 91 or newer wrangler tank and pump from a 4 or 6cyl. no luck yet.

Thank you again for your help.
__________________
STOCK JEEPS (used to) RULE!!!!!!!!!
[QUOTE=RikRotorhead]Why.... some of my best friends have round headlights.[/QUOTE]
[QUOTE=Jeebs;9478201]Dang! I guess thats why they're affectionately called ProCrap![/QUOTE]
orichierich is offline   Reply With Quote
Unread 02-17-2010, 10:33 PM   #10
stoveguy01
Registered User
1989 YJ Wrangler 
 
Join Date: Mar 2008
Location: Bonney Lake, washington
Posts: 193
4.0 head

I done this same swap on my 89 last year I used the 89 alt bracket and just redrilled one of the holes got it to bolt up fine and works great. you will love it when you get it running. one of the best mods Ive done yet
stoveguy01 is offline   Reply With Quote
Unread 02-18-2010, 11:08 AM   #11
orichierich
Registered User
1990 YJ Wrangler 
 
Join Date: Feb 2009
Location: Corona CA.
Posts: 27
im going to hit up the junk yard this weekend to look for the 89 bracket, also another question for DivineKaos and stoveguy01, did the donor vehicle you got the bracket from have A/C? I keep seeing alts and brackets for sale on ebay some say W/AC and WO/AC. I was wondering if the A/C made a difference in the shape of the bracket?
__________________
STOCK JEEPS (used to) RULE!!!!!!!!!
[QUOTE=RikRotorhead]Why.... some of my best friends have round headlights.[/QUOTE]
[QUOTE=Jeebs;9478201]Dang! I guess thats why they're affectionately called ProCrap![/QUOTE]
orichierich is offline   Reply With Quote
Unread 02-18-2010, 09:26 PM   #12
RikRotorhead
Web Wheeler
 
RikRotorhead's Avatar
1988 YJ Wrangler 
 
Join Date: Aug 2008
Location: SloCal
Posts: 8,830
OK we got the alternator problem solved. We modified the stock bracket and got a shorter serpentine belt. Everything lined up and is solid.
Just need to resolve the fuel pump issue.
__________________
Betcha' wish your girlfriend was as dirty as my Jeep!
Zombies hate fast food.
Hang on! This is gunna' be a thrill ride of geriatric proportion!
RJC#512
RikRotorhead is offline   Reply With Quote
Unread 02-18-2010, 09:36 PM   #13
stoveguy01
Registered User
1989 YJ Wrangler 
 
Join Date: Mar 2008
Location: Bonney Lake, washington
Posts: 193
fuel pump

what I did for the fuel pump is pulled my tank than cut the pick up tube I measured the inside of the tank for depth than mounted the pump so I was just shy that length and reinstalled sending unit the fuel pump wires I pulled the thru sending wiring and its grommet off an old gm sending unit I had on hand and replaced the original hooking the wires to the pump and sending unit has worked flawless for me. only down side if you want to call it that iss when I get below a 1/4 tank and turn sharp to were the fuel sloshes to one side In hesitates from lack of fuel never has died tho I figure it makes a good low fuel warning lol
stoveguy01 is offline   Reply With Quote
Unread 03-03-2010, 10:24 AM   #14
orichierich
Registered User
1990 YJ Wrangler 
 
Join Date: Feb 2009
Location: Corona CA.
Posts: 27
I got lucky at the junk yard and found a 1995 yj with the fuel tank/pump complete. I have removed mine and already installed and wired it. my stock wiring on my 90yj had an extra wire to the fuel tank that was powered by the ignition so I cut off the original plug and attached the plug from the 95 so I didnt have to run any wires at all. I used the existing steel fuel lines and had cut the 95 rubber lines from the tank long enough so I didnt have to use any new hose. So I went from a 15 gallon metal tank to a 20 gallon poly tank with a internal fuel pump and it only cost me 53 bucks from the junk yard. Lucky find!!
__________________
STOCK JEEPS (used to) RULE!!!!!!!!!
[QUOTE=RikRotorhead]Why.... some of my best friends have round headlights.[/QUOTE]
[QUOTE=Jeebs;9478201]Dang! I guess thats why they're affectionately called ProCrap![/QUOTE]
orichierich is offline   Reply With Quote
Unread 04-12-2010, 02:00 AM   #15
RookieJeeper01
Registered User
1987 YJ Wrangler 
 
Join Date: Apr 2010
Location: Everett Wa
Posts: 115
Good thread, did you finish the wiring and get it fired up?
RookieJeeper01 is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.