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Unread 08-08-2011, 10:33 AM   #46
Que89YJ
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1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
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River Hippy. You can't just bypass a sensor without effecting the ecm calibration. You need everythig hooked up to troubleshoot it. The Cat won't effect whats going on because its after the sensors. Get a fuel guage on it and see if the pressure is 31-39 psi.

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Unread 08-08-2011, 01:30 PM   #47
riverhippy
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Quote:
Originally Posted by Que89YJ View Post
River Hippy. You can't just bypass a sensor without effecting the ecm calibration. You need everythig hooked up to troubleshoot it. The Cat won't effect whats going on because its after the sensors. Get a fuel guage on it and see if the pressure is 31-39 psi.
sensors are all hooked up. i only have an upstream 02 sensor before the cat (if it were there) the fuel pressure is solid at 31. is there a way to test the fuel pump other than pressure?
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Unread 08-09-2011, 12:56 PM   #48
riverhippy
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mother effin, you have gotto be kidding me. still the same.....runs great, for 45 mins, then sos. what am i missing!!!!!!!!!!!?????????????
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Unread 08-09-2011, 01:27 PM   #49
Que89YJ
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1989 YJ Wrangler 
 
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OK, real quick sumary:
You still have a vacuum leak from the head gasket and the O2 sensor is not connected.
Your pressure is staying at 31 psi when it starts to stumble. (You did the reading while it was happening)
You have replaced: coil, tps, map, cap, rotor, plugs and wires.
It runs for about 30 minutes before anything happens.
When you hit a bump it hesitates
When it happens it starts to backfire and lose power.

Are you throwing codes now?

After you said you hit bumps and it started to hesistate have you gone through and tried shaking and moving the harness to see if it does it?

My offer stands. If you need a hand I can stop by.
Also there is a guy reasonably close to us that carries used YJ parts. He's got everything you could need. Sensors, ecu, etc. He had 9 he was scrapping out for parts:

Tons of jeep wrangler parts several part out jeeps please call text email chris 810-650-3206 with your needs we have a large collection of everything from used parts restoration offroad to maintenance needs new parts
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Unread 08-09-2011, 03:36 PM   #50
riverhippy
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the codes im throwing are 21 and 23....same as before. im checking the wire harness again for continuity. if there is a leak i cant find it in the head or intake manifold. ill soon try a pressure test.

i did notice that the spark stopped for a second when this happens. is it from a bad coil or does it die becuz the engine is stumbling. i appreciate the offer and will probably take you up on it, if for any other reason than to meet...
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Unread 08-09-2011, 10:11 PM   #51
riverhippy
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i put the gun down, its the cps, coding 21 21 ?
OK, not on my way to the beach with my girl yet, however one mystery has been solved, the stalling when i hit a bump is the crank position sensor wiring.

a new problem: im coding 21 then it codes again as 21?

im wondering if this has anything to do with the difference between the cheorkee and the wrangler mat sensor. one repair man for cherokee sez the resitance should be at 3000 ohms or less and the wrangler manual sez 1000 ohms...wtf?
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Unread 08-09-2011, 10:14 PM   #52
riverhippy
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que, lemme know weneva u wanna stop by. i look forward to it. any big projects cmming up, ill be sure to post em..lol...id love ur input
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Unread 08-09-2011, 10:49 PM   #53
cevans87
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it's not code 21 and 21 it's code 33 which is a/c relay (nothing to worry about)

31 psi is not enough fuel pressure (failling pump)

and why am i the only one that realized this

by the way you don't have a carb, you have fuel injection... if you had a carb and had 31psi of fuel... you would blow up... literaly gas would be everywhere untill you blew up...

sounds to me like you problem is happening after you go into open loop on the ecm...try taking your positive cable off and grounding it to something on the motor for 30 seconds... don't not touch it to the negitive post on the battery or you will have a very bad day...

hook it back up and pull the codes again without letting the motor start to see what you get... that will tell you whats wrong (not whats stored on the eprom)

i think though your problem is the fuel pump... classics signs of failure after it has heated up a good bit... the signs that are pointing to it are the presure and the symptoms your having...

good luck
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Unread 08-09-2011, 11:18 PM   #54
Que89YJ
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1989 YJ Wrangler 
 
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Disconnect the battery for a long 10 count and clear the code. The sensors are the same. Recheck it.
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Unread 08-10-2011, 09:01 AM   #55
Que89YJ
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LOL I didnt catch that 21 and 21. Thats great Cevans!
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Unread 08-10-2011, 09:38 AM   #56
riverhippy
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Quote:
Originally Posted by Que89YJ View Post
LOL I didnt catch that 21 and 21. Thats great Cevans!
thanks for the math...that actually would be really funny if true. codes: 12...33...23...21...21...55 i never had it code twice for the same one.

i thought the 91 w/mfi was common knowledge so i just refer to it as "carb".my bad, sorry.

regarding the fuel pump, every manual ive read (3 total) sez the fuel pressure should be at 31.5, which it is. if this is an indication of lowering pressure is there any other way to check the pump?
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Unread 08-10-2011, 10:32 AM   #57
Que89YJ
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Your pressure was at 31 which is fine. You can jumper the fuel pump relay between pins 30 and 87 in the relay socket with a paper clip or a short wire. Let it run for an hour monitoring the pressure. 23 is your MAT on the manifold right next to the AIS Motor on the throttle body.
I am trying to follow where you are at with your repair. You still have a leak in the head gasket, you repaired your O2 sensor and your crank sensor. Is that about right?
What symptoms is there left? Check the MAT sensor out. I want to see you get the GF out on Metro Beach...and work on getting that kiss.
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Unread 08-12-2011, 03:50 PM   #58
riverhippy
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i installled a new cps, now i got no spark...wtf. i hate my life...lol
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Unread 08-12-2011, 08:51 PM   #59
johnny27030
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If you replaced your cps and now you have no spark. I would without a reasonable doubt say you have faulty wiring to the cps.
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Unread 08-12-2011, 09:02 PM   #60
riverhippy
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Quote:
Originally Posted by johnny27030 View Post
If you replaced your cps and now you have no spark. I would without a reasonable doubt say you have faulty wiring to the cps.
thnks, wanted to make sure that the cps can stop spark, you validated my theory, working on it now.
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