cam - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 03-13-2001, 08:05 PM
**DONOTDELETE**
Guest
 
Posts: n/a
cam

have 84 CJ with 4.2,MPI installed. Bored out .40 needs new cam. Does a 4.0 cam fit it that has fuel injection. Looking for suggestions. HELP!!

Sponsored Links
Advertisement
 
post #2 of (permalink) Old 03-15-2001, 06:35 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: cam

Hey-Stock fuel injection is tough to play around with when you add a cam. If you can find a 'adjustable fuel regulator you will be able to adjust the out put of the fuel to match the needed flow for the cam. Ask a mopar performance dealer-speed shop, and see if anyone else has done your swap and a cam. Also ask Cran, Comp, Lunati and Edelbrock cams to see if there is a compatible cam. I believe Comp Cams has a series of cams called "Compu-Cams", the obviously computer controlled compatible cams.

MARK (OIIIIO) LANGMOTORSPORTS
1977/CJ7/GLASSTUB/460CIFORD/C6AUTO/4"LIFT/33'S
post #3 of (permalink) Old 03-15-2001, 07:01 PM
 
Join Date: Dec 1999
Posts: 5,140
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: cam

is the MPI the mopar kit? or stuff swapped from a 4.0?

I would go with the manufacturers recomendations on an EFI cam. ( im assuming the mopar kit has a recomendation?!) otherwise stock is probably where the EPROM is designed to work, cam grinds that arent stock MAY or MAY NOT work correctly with the EPROM the injection system is using

You wont be able to adjust it with an adjustable regulator, you could with a carb ( to some extent)
but not with EFI

OzarkJeep

"If thats the way that you want it, well thats the way I want it more..."
ozarkjeep is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 03-15-2001, 07:53 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: cam

..Osark...not that im telling you your wrong but fuel injected vehicles have a certain allowance of flow per manufacturers specifications...on the modified Camaros and turbo, twin turbo or the supercharged Mustangs we've delt with... if you have a slight stumble or lean spot you can regulate witha adjustable fuel pressure regulator...say on his Jeep if the cam he has is off a little. The fuel injected vehicles have fuel pump that puts out 39 PSI and the F.P.R. then cuts it down to the 19 PSI the injectors call for, that extra amount of fuel is there and can be used to our advantage to adjust as necessary.

MARK (OIIIIO) LANGMOTORSPORTS
1977/CJ7/GLASSTUB/460CIFORD/C6AUTO/4"LIFT/33'S
post #5 of (permalink) Old 03-15-2001, 07:53 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: cam

post #6 of (permalink) Old 03-15-2001, 09:02 PM
 
Join Date: Dec 1999
Posts: 5,140
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: cam

I thought FI engines ran alot more than 39 or 19 lbs of pressure to the injectors?

unless something is something wrong in the fuel map/curve, or there is a conflict between the cam profile and fuel delivery parameters, you shouldnt have to adjust the fuel pressure.




OzarkJeep

"If thats the way that you want it, well thats the way I want it more..."
ozarkjeep is offline  
post #7 of (permalink) Old 03-15-2001, 09:45 PM
 
Join Date: Sep 1999
Posts: 2,137
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: cam

Just call Hesco and get a cam from them.
http://www.hescosc.com/
They co-developed and distribute the MPI kit and they've dyno tested all the various setups and will have the perfect cam for you ...
Don't take chances and make guesses .... that's not to smart ...
My Hesco/Clay Smith grind roars past 5000 RPM and also has tons of grunt ...


JAF
http://www.monsterslayer.com/jeep
Jaffer is offline  
post #8 of (permalink) Old 03-15-2001, 11:18 PM
Can't Get Enough
 
Join Date: Sep 1999
Location: Cotopaxi, Colorado
Posts: 1,036
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: cam

I don't know if the 4.0l cam will fit the 4.2 or not. The spec sheet says that it won't, but I believe that is because of the missing lobe for the fuel pump. The biggest problem with aftermarket cams and fuel injection is the loss of manifold vacuum at idle. This plays havioc with mixtures at idle because of the m.a.p. sensor thinking there is a load on the engine. I have run the stage 1 and stage 11 cams in both a 4.0 and a 4.5 stroker with great success. Hesco would be the one to talk to.

dorfs is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome