just cant get it to run - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 04-06-2012, 12:39 PM   #1
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
just cant get it to run

After two months of replacing parts, tracing wires and getting nowhere i sit with a dead 90 yj in the driveway. After reading other forums i have replaced all but the computer. As it sits right now the fuel pump stays running when the key is switched to "run" fuel is making it to the tb. Any thoughts?

Mark Tice is offline   Quote
Old 04-06-2012, 12:43 PM   #2
IITYWTMWYBMAB

WF Supporting Member
::WF Administrator::
 
4Jeepn's Avatar
 
Join Date: Apr 2005
Location: Florence, KY
Posts: 10,636
Images: 5
4 or 6cly?

__________________
79.96.85.00.01.97.00.97.93.97.95.94
CJ.XJ.CJ. TJ. TJ.ZJ. TJ.TJ. ZJ.ZJ.YJ. XJ
4Jeepn is offline   Quote
Old 04-06-2012, 04:03 PM   #3
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
4
Mark Tice is offline   Quote
Old 04-06-2012, 05:08 PM   #4
IITYWTMWYBMAB

WF Supporting Member
::WF Administrator::
 
4Jeepn's Avatar
 
Join Date: Apr 2005
Location: Florence, KY
Posts: 10,636
Images: 5
does it turn over? If so are you getting spark at the plugs? Have you tried to get any codes off it?
__________________
79.96.85.00.01.97.00.97.93.97.95.94
CJ.XJ.CJ. TJ. TJ.ZJ. TJ.TJ. ZJ.ZJ.YJ. XJ
4Jeepn is offline   Quote
Old 04-06-2012, 05:17 PM   #5
Jeeper
 
NHrubicon's Avatar
 
Join Date: Jul 2010
Location: New Hampshire
Posts: 844
Images: 1
I hate to say it, but I'd guess it's time to replace the computer. I had a 94 YJ, 4 cyl, rebuilt and modified, spent over $4000 just in parts...and a week after we got it back from the shop, it did exactly what yours is doing. Dead...turn over all day but nothing. Mechanic said to order a new computer-give them the VIN number or something-they ask for it-and it arrived a couple days later. Plugged it in...and as far as I know it is running still-sold it last year. When we took the old one out, when the case came off-you could see the smoke and charred contacts where it had overheated and committed suicide.
NHrubicon is offline   Quote
Old 04-06-2012, 05:18 PM   #6
Jeeper
 
Join Date: Jan 2010
Location: Las Cruces, NM
Posts: 2,303
If you are getting fuel and spark, the only thing left is timing and proper fuel mixture, but even if its set rich you should get a burp now and then.
__________________
2013 WRANGLER SPORT 2 DR., V-6 ,AUTO,HARD TOP
(Sold)1994 Jeep Wrangler 2.5L, Bestop top
/w steel half door and slider windows
5 speed, 2.5" lift, 31" tires,rack lights
Garyk is offline   Quote
Old 04-06-2012, 05:18 PM   #7
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
It dose fire, no codes, it dose roll over. If i pull the relay for the fuel pump the jeep will start for a few seconds b/c it's not being flooded
Mark Tice is offline   Quote
Old 04-06-2012, 05:19 PM   #8
Jeeper
 
Join Date: Jan 2010
Location: Las Cruces, NM
Posts: 2,303
So it floods??Sounds like a TB problem
__________________
2013 WRANGLER SPORT 2 DR., V-6 ,AUTO,HARD TOP
(Sold)1994 Jeep Wrangler 2.5L, Bestop top
/w steel half door and slider windows
5 speed, 2.5" lift, 31" tires,rack lights
Garyk is offline   Quote
Old 04-06-2012, 05:22 PM   #9
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
If i pull the cap off of the tb it will shoot fuel at you when turned to run
Mark Tice is offline   Quote
Old 04-06-2012, 05:35 PM   #10
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
Quote:
Originally Posted by Mark Tice View Post
the fuel pump stays running when the key is switched to "run" fuel is making it to the tb. Any thoughts?
You must realize that the fuel pump isn't supposed to stay running with the key in "run" if it doesn't start. Has it done this for a while? Have you done something with the electrical system?
brentd711 is offline   Quote
Old 04-06-2012, 05:59 PM   #11
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
I know it's not supposed to stay running, I have replaced corroded connections, the timing, everything dealing with ignition, the fuel pump, and reseated all of the fuses.
Mark Tice is offline   Quote
Old 04-06-2012, 07:40 PM   #12
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
I think the ECM controls the fuel pump in the '87-'90 and if it doesn't see a crank signal (from the CPS) in a couple of seconds it shuts the pump off. Later models have an ASD relay in the PCM. Sounds like you may have an ECM issue.

Here's a diagnostic guide for the TBI system.
brentd711 is offline   Quote
Old 04-06-2012, 07:58 PM   #13
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
Thanks, I haven't seen a diagnostics page like this. I replaced the CPS a couple weeks ago. I agree ECU is the next purchase. Thank you all for taking the time to reply to the post.
Mark Tice is offline   Quote
Old 04-06-2012, 07:59 PM   #14
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
ECM is the next purchase... typo above
Mark Tice is offline   Quote
Old 04-23-2012, 06:29 PM   #15
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
New ecm installed and now the fuel pumps not getting power. This thing really hates me!
Mark Tice is offline   Quote
Old 04-23-2012, 07:24 PM   #16
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
At least it's not flooding. Have you swapped relays, checked fuses and ground wire?
brentd711 is offline   Quote
Old 04-23-2012, 07:33 PM   #17
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
New relays, grounds are good.
Mark Tice is offline   Quote
Old 04-23-2012, 07:33 PM   #18
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
What fuse? I cant find one that is bad
Mark Tice is offline   Quote
Old 04-24-2012, 08:49 AM   #19
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
Would there be anything on the throttle body that would cause the symptoms?
Mark Tice is offline   Quote
Old 04-24-2012, 01:07 PM   #20
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
There's a wide open throttle switch that's supposed to cut off fuel supply when you put the pedal to the floor (when it's flooded). It's a white plastic thingie with a microswitch on the throttle cable bracket at the TB. You can try disconnecting it and see if that's the issue.
brentd711 is offline   Quote
Old 04-24-2012, 01:21 PM   #21
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
I'll look for it.
Mark Tice is offline   Quote
Old 04-24-2012, 01:27 PM   #22
Jeeper
 
DieLawn19k's Avatar
 
Join Date: Apr 2012
Location: Fort Benning, GA
Posts: 117
Ouch, sounds like you bought my old Jeep, it isn't a red jeep with a lift is it? The only way that piece would run was if I unplugged the alternator. Good luck man, I definitely feel your pain.
__________________
Currently a Tanker Without A Tank!
DieLawn19k is offline   Quote
Old 04-24-2012, 01:49 PM   #23
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
Thanks, I've gotten used to the disappointment the last few months. Im learning alot, but cant seem to catch the "ghost"
Mark Tice is offline   Quote
Old 04-24-2012, 01:54 PM   #24
Jeeper
 
DieLawn19k's Avatar
 
Join Date: Apr 2012
Location: Fort Benning, GA
Posts: 117
I hear ya, I gave up on mine after dumping money into it for 6 months, sold it for a grand, and just bought a '93 grand cherokee to last me until basic. Got a wrangler again now though thank god.
__________________
Currently a Tanker Without A Tank!
DieLawn19k is offline   Quote
Old 04-24-2012, 01:57 PM   #25
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
Mark, if you haven't already you should try putting 12V to the fuel pump just to make sure it isn't a dead pump.
brentd711 is offline   Quote
Old 04-24-2012, 02:02 PM   #26
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
Thanks i have. I even replaced it a month ago. With no success i dropped the tank once more and verified the pump once more. After i installed the refurbished computer yesterday its not getting voltage at the pump (checked with s meter).
Mark Tice is offline   Quote
Old 04-24-2012, 05:07 PM   #27
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
Disconnected the wide open switch and still no voltage back by the pump. I checked, 3 legs on the relay have 12v when key is turned to "run".?????
Mark Tice is offline   Quote
Old 04-24-2012, 09:19 PM   #28
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
12V off the relay but nothing at the harness for the pump? Did you use harness ground or good clean metal ground point on the frame?

It would be a real fluke but is it possible the ECM connector isn't quite right...may be worthwhile to unplug the harness at the ECM and reconnect it if that's all you've changed since the pump last ran.
brentd711 is offline   Quote
Old 04-25-2012, 09:47 AM   #29
Jeeper
 
Mark Tice's Avatar
 
Join Date: Apr 2012
Posts: 35
I scrubbed the ground clean and replaced the crimp on connection. Ill retry the connector this afternoon.
Mark Tice is offline   Quote
Old 04-25-2012, 10:03 AM   #30
Jeeper
 
Join Date: Aug 2011
Location: Central Maine
Posts: 275
If you think you got a bad ECM let me know, I've got one from a '90 2.5L 5-spd.

brentd711 is offline   Quote
Reply

Thread Tools

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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wanting to buy a jeep but clueless? rach87 General Jeep Discussion 18 04-10-2012 08:09 PM
New to all this. Need tips on replacing brake lines MyOldJeep WF New Member Check In 7 04-09-2012 04:21 AM
New Jeep, new to the forum NukeRef WF New Member Check In 10 04-08-2012 12:05 PM
16 yr old son wants a Jeep and has $15k to spend - looking for recs Longhorngary General Jeep Discussion 17 04-06-2012 09:10 PM



Download our Mobile App

» Featured Product

All times are GMT -5. The time now is 04:03 PM.


User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC