Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: giorno71 on September 29, 2009, 07:14:19 PM

Title: engine code and running like crap
Post by: giorno71 on September 29, 2009, 07:14:19 PM
i did a motor swap from a 2.5 to a cherokee 4.0 ho  in my yj now i have a code 73 and 75 and cant find info on them. jeep ran great for about 2or 3 months and now i cant drive it . it it started sputtering at arround 100 degrees now it dose it even when cold  i have changed every sensor i can find  cap rotor and wires and a new fuel filter . i did swap in a biggert fuel tank from a yj but used my pump and sending unit, just changed the float arm to the longer one .
now the rpms will fall to almost stalling but dosent then reves up and back down to almost stalling. if im driving and it starts to sputter the rpms dont change if there at 2000 they stay at 2000 but lose all power also the air intake soundes like its a scraping noise and really loud when it sputters  but when it goes back to normal so dose the intake  



Any ideas would be a big help
Title: Re: engine code and running like crap
Post by: giorno71 on September 29, 2009, 10:46:31 PM
the doner was a 92 into a 94 yj  using the doner ecm. the codes are from the on board code check.  when it was in the cherokee it hade no problems and no codes. i had taken the cherokee on a 6 hour road trip befor the swap and not one problem arose
Title: Re: engine code and running like crap
Post by: WhiteOut on September 29, 2009, 10:48:47 PM
Sounds like the CPS
Title: Re: engine code and running like crap
Post by: giorno71 on September 29, 2009, 10:53:40 PM
swaped out the cps and wasent the issue  my buddy acually put mine in his jeep and it ran like a top
Title: Re: engine code and running like crap
Post by: frenchy on September 30, 2009, 08:08:49 AM
Did this issue start right after swapping to the larger fuel tank, or was that done originally and ran fine with it?
Title: Re: engine code and running like crap
Post by: BlackYJ on September 30, 2009, 08:40:10 AM
Here is a link for the YJ codes, http://www.jeephorizons.com/tech/yj_codes.html (http://www.jeephorizons.com/tech/yj_codes.html) and as mentioned there is nothing for 73 or 75.  Did you count it correctly?
Title: Re: engine code and running like crap
Post by: giorno71 on September 30, 2009, 03:14:03 PM
yep read the code right even checked twicw more just to be sure. also how do you erase the codes from the pcm i disconected the batt but it didnt work. the wiring is the stock 2.5 wiring. icant seem to find the plug for the code reader either
Title: Re: engine code and running like crap
Post by: WhiteOut on September 30, 2009, 03:21:11 PM
There is also no codes like that for an XJ.  Are you using the key on,off trick?
Title: Re: engine code and running like crap
Post by: frenchy on September 30, 2009, 03:32:41 PM
Put gas in it.
Title: Re: engine code and running like crap
Post by: giorno71 on September 30, 2009, 03:59:34 PM
yep  using the key thing  and there is over half a tank of gas in it
Title: Re: engine code and running like crap
Post by: SwampSinger on September 30, 2009, 04:09:18 PM
yep  using the key thing  and there is over half a tank of gas in it

go to Autovalue,.. borrow thier OBD2 reader and get the real codes
Title: Re: engine code and running like crap
Post by: giorno71 on September 30, 2009, 06:18:01 PM
yj and xj wiring harnes is virtualy the same the only differance is i had to change two ends on a couple plugs and wire in the two more cylinders, and that was it . it fired right up and like i said it ran great for a few months with no issues and its my only vehical so i drive it every day.  i dont have a autovalue here in medicine hat so thats not an option.
Title: Re: engine code and running like crap
Post by: BlackYJ on October 01, 2009, 07:14:16 AM
yj and xj wiring harnes is virtualy the same the only differance is i had to change two ends on a couple plugs and wire in the two more cylinders, and that was it . it fired right up and like i said it ran great for a few months with no issues and its my only vehical so i drive it every day.  i dont have a autovalue here in medicine hat so thats not an option.

Any auto parts store should scan your jeep for free.  Try Crappy Tire
Title: Re: engine code and running like crap
Post by: BlackYJ on October 01, 2009, 07:15:37 AM
Hmm... is the wiring the same between the YJ and XJ? As I kinda followed along, I got the impression it's the 2.5 YJ harness with the 4.0 XJ motor and ECM... could that have something to do with it?

Pat, I have the exact same setup in my YJ.  The bulkhead connectors to the firewall are different, so it is easier to wire in 2 more cylinder than to try and change the connectors
Title: Re: engine code and running like crap
Post by: BBD on October 02, 2009, 09:15:34 PM
not sure if that year has them. but how do you O2 sensors look?
Title: Re: engine code and running like crap
Post by: SwampSinger on October 04, 2009, 10:55:50 AM
yj and xj wiring harnes is virtualy the same the only differance is i had to change two ends on a couple plugs and wire in the two more cylinders, and that was it . it fired right up and like i said it ran great for a few months with no issues and its my only vehical so i drive it every day.  i dont have a autovalue here in medicine hat so thats not an option.

I agree with BlackYJ ...There must be a part store in good ol' MH...it is a fair size town .Crappy tire might chanrge you for it though. Try to find a place they sell part but don't have any garage bay... NAPA, Part Source ?

Most of these places have OBDII readers. You can borrow them if you leave your credit card # with them. They do that because they want you to buy the part you need at their business after. Make sense...