some technical advice needed 4.2/4.0 + Howell TBi & Cali smog - 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 > some technical advice needed 4.2/4.0 + Howell TBi & Cali smog

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineDan's Old as Dirt Birthday Sale!GEARSHADE Pocket Tops in stock and available at ROCKRIDGE

Reply
Unread 06-19-2013, 02:52 PM   #1
kgb_m3
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2011
Location: San Diego, CA
Posts: 910
some technical advice needed 4.2/4.0 + Howell TBi & Cali smog

Need some technical advice on how to approach this from the most practical point. The need to pass smog and the want to stay CA legal with added HP/TQ numbers.

I've been building an 89 jeep YJ currently running 4.2l/auto with MC2150. Need it to pass smog in California by November this year. I'm leaning toward ordering a rebuild engine from Precision and slapping the Howell TBi to keep things legal and reliable.

Contacted both companies and still have trouble figuring a few things out. Is it possible to run 4.0/4.2 with Howell TBi and still pass smog?
If not, will the Howell TBi work with a beefed up 4.2 (aggressive cam, higher compression, etc) and still pass smog? I'm concerned with mapping of the Howell ecu and how it would work with anything other than a bone stock 4.2l 258

__________________
89 YJ 4.2L http://www.jeepforum.com/forum/f12/kgb-89-yj-storyline-build-thread-1520814/
96 XJ 4.0L http://www.jeepforum.com/forum/f177/600-96-xj-budget-daily-overland-build-1855418/
http://www.jeepsunclassified.com
kgb_m3 is offline   Reply With Quote
Unread 06-19-2013, 03:35 PM   #2
jbolty
Moderator
 
jbolty's Avatar
1990 YJ Wrangler 
 
Join Date: Jun 2007
Location: San Diego, CA
Posts: 15,630
Those questions are best directed at Howell but I can predict their answer will be they have been approved and tested under certain conditions and can not comment on other situations.

If you are considering an engine swap why not just go with a 4.0 and the included FI system? The junkyards are usually full of XJs. In your place I would get the engine, computer and AW4 transmission and put in the whole thing
__________________
.
"The right to be heard does not necessarily include the right to be taken seriously." —Hubert Humphrey
.
If you live within wheeling distance of San Diego county, click here
jbolty is offline   Reply With Quote
Unread 06-19-2013, 06:05 PM   #3
kgb_m3
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2011
Location: San Diego, CA
Posts: 910
I did consider that route and may end up doing so. Howell told me exactly what you posted! I anticipated them not being much help.

Could pls you tell me some more about your setup since you're in socal as well and have a rig that smogs.
__________________
89 YJ 4.2L http://www.jeepforum.com/forum/f12/kgb-89-yj-storyline-build-thread-1520814/
96 XJ 4.0L http://www.jeepforum.com/forum/f177/600-96-xj-budget-daily-overland-build-1855418/
http://www.jeepsunclassified.com
kgb_m3 is offline   Reply With Quote
Unread 06-19-2013, 06:12 PM   #4
jbolty
Moderator
 
jbolty's Avatar
1990 YJ Wrangler 
 
Join Date: Jun 2007
Location: San Diego, CA
Posts: 15,630
I have a stock 4.2 with a Howell CA kit. Smogs with flying colors. I also have an HEI distributor.

You can look at it if you want.

You can sometimes find running XJs on craigslist for really cheap. They get sold for almost nothing if they will not pass smog. Get one of those that you know runs and have the engine rebuilt for about $1200 or so. Add another $500 for bits and pieces and be living the high life.
__________________
.
"The right to be heard does not necessarily include the right to be taken seriously." —Hubert Humphrey
.
If you live within wheeling distance of San Diego county, click here
jbolty is offline   Reply With Quote
Unread 06-19-2013, 06:56 PM   #5
kgb_m3
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2011
Location: San Diego, CA
Posts: 910
Thanks for a quick reply,

Smog is due in November, next on the list is the 8.8 swap that I already have sitting at the house. The plan is to get everything done before smog's due. Time and money of course never work in your favor

I would love to see your setup in person. If you're not too busy this weekend, my gf is out of town and all I have planned was Jeep work. Probably going to have a few buddies come hang out and wrench on stuff. You're more than welcome to swing by and have a beer or two, I can check out your setup and make some better decisions. I'm in Kearny Mesa.

Don't like having down time with the jeep and as much as I would like to swap the whole thing from XJ. Howell with stock 4.2 seems a much easier and faster way to get by. I can refresh the 4.2 as well in the process.

Did you buy the Howell full price or piece together?
__________________
89 YJ 4.2L http://www.jeepforum.com/forum/f12/kgb-89-yj-storyline-build-thread-1520814/
96 XJ 4.0L http://www.jeepforum.com/forum/f177/600-96-xj-budget-daily-overland-build-1855418/
http://www.jeepsunclassified.com
kgb_m3 is offline   Reply With Quote
Unread 06-19-2013, 10:42 PM   #6
jbolty
Moderator
 
jbolty's Avatar
1990 YJ Wrangler 
 
Join Date: Jun 2007
Location: San Diego, CA
Posts: 15,630
Quote:
Originally Posted by kgb_m3 View Post
Thanks for a quick reply,

Smog is due in November, next on the list is the 8.8 swap that I already have sitting at the house. The plan is to get everything done before smog's due. Time and money of course never work in your favor

I would love to see your setup in person. If you're not too busy this weekend, my gf is out of town and all I have planned was Jeep work. Probably going to have a few buddies come hang out and wrench on stuff. You're more than welcome to swing by and have a beer or two, I can check out your setup and make some better decisions. I'm in Kearny Mesa.

Don't like having down time with the jeep and as much as I would like to swap the whole thing from XJ. Howell with stock 4.2 seems a much easier and faster way to get by. I can refresh the 4.2 as well in the process.

Did you buy the Howell full price or piece together?
Full price, it's the only way to get the CARB sticker.

I'm booked Saturday, but maybe sunday.

I'm in Clairemont. PM your info.
__________________
.
"The right to be heard does not necessarily include the right to be taken seriously." —Hubert Humphrey
.
If you live within wheeling distance of San Diego county, click here
jbolty is offline   Reply With Quote
Unread 06-20-2013, 12:21 AM   #7
kgb_m3
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2011
Location: San Diego, CA
Posts: 910
PMed. I was just researching on how to piece one together, possible but carb sticker and 4.3l mapping won't work exact with 258amc. I'm going to buy the kit directly from Howell. It is what it is, gotta pay to play.
__________________
89 YJ 4.2L http://www.jeepforum.com/forum/f12/kgb-89-yj-storyline-build-thread-1520814/
96 XJ 4.0L http://www.jeepforum.com/forum/f177/600-96-xj-budget-daily-overland-build-1855418/
http://www.jeepsunclassified.com
kgb_m3 is offline   Reply With Quote
Unread 06-20-2013, 01:06 PM   #8
kgb_m3
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2011
Location: San Diego, CA
Posts: 910
After a few more phone calls and a hours of reading it's been done with great success. 4.2/4.0 and howell tbi with a chip added to ecu module. Passes smog with flying colors. Will be ordering the head from clearwater, comes with welded water holes and 7120 casting. Then a trip to a junk yard for exhaust mani and valve cover.. This thing is going to scream once everything is done along with the HEI dizzy.
__________________
89 YJ 4.2L http://www.jeepforum.com/forum/f12/kgb-89-yj-storyline-build-thread-1520814/
96 XJ 4.0L http://www.jeepforum.com/forum/f177/600-96-xj-budget-daily-overland-build-1855418/
http://www.jeepsunclassified.com
kgb_m3 is offline   Reply With Quote
Unread 09-06-2013, 11:18 AM   #9
drespecki
Registered User
1983 CJ7 
 
Join Date: Jan 2007
Location: Arizona
Posts: 1,167
Do you know if the 4.0 head needs higher RPM's to get the hp out of it? I am considering the exact same setup as you but heard that to reach max hp and torque, the 4.0 head (which breathes easier) has to run about 1000 rpms higher?
__________________
It only hurts while you're breathing..
drespecki is offline   Reply With Quote
Unread 09-07-2013, 10:32 AM   #10
blown50
Registered User
1987 YJ Wrangler 
 
Join Date: Apr 2007
Location: MS, MS.
Posts: 134
Quote:
Originally Posted by drespecki
Do you know if the 4.0 head needs higher RPM's to get the hp out of it? I am considering the exact same setup as you but heard that to reach max hp and torque, the 4.0 head (which breathes easier) has to run about 1000 rpms higher?
I did the 4.0 set up on my 4.2 before I built the stroker. I think the people that says it needs higher rpm didn't know how to tune! Mine stayed the same r maybe had a touch more bottom end, this could be attributed to better sealing valves r a little more timing that can be run with the head. But I calling a 1000 more rpms a myth! Do the swap u won't be disappointed , and u will have a better head when u build the stroker
blown50 is offline   Reply With Quote




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.