Gotta get rid of this computer! - JeepForum.com

Reply
 
LinkBack Thread Tools
post #1 of 17 Old 12-20-2012, 10:30 AM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
Gotta get rid of this computer!

Having major issues with engine performance! Just traded for the YJ and the PO rebuilt the engine his self, could not get it to run right and gave up.

So I've checked the timing, TDC #1 valves closed on #1 etc. Engine will run but misses and from the look of the plugs its running rich. Been reading lots of threads but not finding anything that has helped. This is my first 4 cyl Jeep and not real up to speed on them, but i have found that this engine configuration was used only in 87 and 88 year models. As it is a TBI system I'm ready to jerk the TB and electronic ingition and go old school, but I've yet to find any write ups on this mod.

I'm sure someone has done this before. I have a Motorcraft version of the webber carb i could rebuild and use, if it will work on the 2.5l, provided i can get someone to point me in the direction of which dizzy to use.

I've read about the brain surgery thing and from what I've read i don't think it applies to the setup in my YJ.

Thanks in advance for any help you can offer!

jcarr74015 is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 12-20-2012, 10:49 AM
Jeepsr4me
Registered User
 
Join Date: Dec 2004
Posts: 8,831
The TBI is almost too simple to work on and get to running perfect. You need to start out with a good understanding of it and then check simple things like , compression, weather the timing is set correctly, if there is enough fuel pressure.
Again its TOOOOOOOO simple.
Jeepsr4me is offline  
post #3 of 17 Old 12-20-2012, 12:42 PM
jokerchief462
Registered User
1989 YJ Wrangler 
 
Join Date: Nov 2010
Location: Sin City
Posts: 2,881
Timing on the 2.5 is set by ecu at 8 degrees BTC. If it is running rich it could be several things. Tstat 195 should have operating temp at 210. O2 sensor , temp sensor for air and water on intake. TPS on throttle body, map sensor on firewall. Leaking vacuum lines. All players because they talk to ecu which decides fuel air mixture and timing.

89YJ 2.5L TBI, AX-5, NP231 SYE, Ford 8.8, Yukon Grizzly, Tom Woods Shaft, 33" BFG T/As, 4" lift, Warn VR10000s.

AF Jeep Club Tail #184
jokerchief462 is offline  
post #4 of 17 Old 12-20-2012, 04:35 PM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
I'm fimiliar with all the componets, just not having any luck at cleaning up the PO's mess!

I found the temp gauge wire loose under the hood and can't find a temp sended anywhere.

ISM is not connected and appears to have had a hammer taken to it!

Most vacuum lines appear in-tact but I've not sprayed them down to see if i get an RPM increase.

Here's a posser shot after i got it running a little bit last evening.



Considering that I have less than $2000 cash invested in this, I feel I'm doing okay for now.

Maybe I'll put a ISM in it and change out the t-stat and existing senders and replace those that are missing and see how she runs.

I like the FI , but i hate the headsches when it comes to cleaning up someone elses FI mess!

You should see the mess they made of the 3" body lift!
jcarr74015 is offline  
post #5 of 17 Old 12-20-2012, 07:14 PM
jokerchief462
Registered User
1989 YJ Wrangler 
 
Join Date: Nov 2010
Location: Sin City
Posts: 2,881
Fortunately my PO did nothing but drive it. No butchered wires no mechanical who ha at all and n o real rust as those from back east show us. So mine was really easy to work on. If you need anything post it up we have the answers I chased all mine trying to pass a NV smog so I got really good at all that crap that talks to the computer to fix the timing and mixture. Found all my answers here in mutiple threads.

89YJ 2.5L TBI, AX-5, NP231 SYE, Ford 8.8, Yukon Grizzly, Tom Woods Shaft, 33" BFG T/As, 4" lift, Warn VR10000s.

AF Jeep Club Tail #184
jokerchief462 is offline  
post #6 of 17 Old 12-20-2012, 07:54 PM
Kuntryboy816
Web Wheeler
 
Kuntryboy816's Avatar
1989 YJ Wrangler 
 
Join Date: Jul 2010
Location: Newark
Posts: 1,096
Garage
For a split second I imagined your jeep had a jet engine.... then I realized it was only a rim...

Quote:
Originally Posted by 14Sport View Post
Until you know exactly what is underneath the, well, not really sure what to call them...mistakes...it's hard to come up with a plan of action.
Kuntryboy816 is offline  
post #7 of 17 Old 12-20-2012, 08:06 PM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
I only wish it was turbine powered. Then I could combine two of my hobbies off roading and flying. I haven't worked on a gasoline injection system in years, been working on diesel injection systems for the last 10-15 yrs and I gotta get myself back in that swing. I was working as a Chrysler mechanic before I got out of high school. Then about 5 yrs outta HS I started working on heavy equip. And now I must retrain to work on little stuff again.
jcarr74015 is offline  
post #8 of 17 Old 12-20-2012, 08:43 PM
Kuntryboy816
Web Wheeler
 
Kuntryboy816's Avatar
1989 YJ Wrangler 
 
Join Date: Jul 2010
Location: Newark
Posts: 1,096
Garage
Or you could get rid of the hamster wheel and drop a diesel in your Jeep!

Quote:
Originally Posted by 14Sport View Post
Until you know exactly what is underneath the, well, not really sure what to call them...mistakes...it's hard to come up with a plan of action.
Kuntryboy816 is offline  
post #9 of 17 Old 12-20-2012, 09:43 PM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
Some how I don't see a c13 cat fitting under the hood of a YJ.
jcarr74015 is offline  
post #10 of 17 Old 12-20-2012, 10:28 PM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
Brought home fuel pressure gauge and a few other tools that for some reason I've not used in 10 plus years and will try and see what I find this weekend.
jcarr74015 is offline  
post #11 of 17 Old 12-22-2012, 09:46 AM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
This morning i found the O2 sensor unplugged and still no luck finding the temp sensor.no place to just connect the fuel pressure guage so i'll have to install a tee to get fuel pressure.

On the other hand I have no fire this morning???

I have power to the igniter and I cleaned the connections and grounds and still no fire. to make things worse no one in town has either piece! Is there an aftermarket that will work in place of OEM ignition?
jcarr74015 is offline  
post #12 of 17 Old 12-22-2012, 10:50 AM
Mark05059
Registered User
1989 YJ Wrangler 
 
Join Date: Mar 2009
Location: quechee Vermont
Posts: 4,699
there should be a fitting on the fuel line to the TBI to install the pressure gage.

1998 ZJ 5.2 Auto

1989 Wrangler Black Bone Stock 2.5l 5spd
/l , [____],
|---L--[]lllllll[]-
()_) ()_)==O=)_)
Mark05059 is offline  
post #13 of 17 Old 12-22-2012, 01:36 PM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
Ok maybe i've been away from the fuel injected gassers for to long, but then again this jeep dates back before i started working in the car dealerships.

There's no wires coming out of the dizzy? In the chiltons manual I find where the engine should have a sensor on a trigger wheel mounted to the flywheel. guess i try and find a crank sensor first, it will likely be less expensive than the coil and igniter.
jcarr74015 is offline  
post #14 of 17 Old 12-22-2012, 02:15 PM
Jeepsr4me
Registered User
 
Join Date: Dec 2004
Posts: 8,831
what is a igniter in relation to a jeep?
Jeepsr4me is offline  
post #15 of 17 Old 12-22-2012, 03:10 PM Thread Starter
jcarr74015
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2011
Location: catoosa
Posts: 95
Sorry the guy at O'Reilly's called it that. It's the module under the coil. Maybe the ignition control module. Sorry I'm still retraining myself to get back to gasser terms and not oil burner terms.
jcarr74015 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com 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 e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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 Off
Pingbacks are On
Refbacks are On

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