Jeep #6 - Page 4 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Jeep #6

Truc-Lite LED Headlights! OCONEE OFF-ROAD 706-534-9955Labor Day Sale!The Original 3/8" Ruffstuff Diff Cover!

Reply
Unread 12-23-2013, 09:28 PM   #46
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
31 psi. I would start with the psr. test. Check bleed down time too. It should stay above 20 for moor than 20 minutes. This checks for leaking injectors and check valve.

Que89YJ is offline   Reply With Quote
Unread 12-23-2013, 09:56 PM   #47
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
Thank you. I'll try to get one from work tomorrow
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-24-2013, 06:57 AM   #48
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
So for kicks today I checked the fuel rail bleeder valve before starting it.. Nothing came out. It was cold obviously. Think an injector is leaking ?
Mechanics at work said try some carb cleaner around the intake manifold see if a gasket is bad. I've yet to try that too. Again what gets me is only when it is cold. Running down the road it is ok. Only hesitates on acceleration every once in a blue moon.
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-24-2013, 11:00 AM   #49
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
Lean code is either a low fuel pressure or the most common is a leaking or cracked exhaust manifold. Check for cracks around the collector tubes and loose bolts on the manifold itself.
Que89YJ is offline   Reply With Quote
Unread 12-26-2013, 12:19 PM   #50
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
Exhaust and the bolts are ok. Again I have to take some cRb cleaner and spray around the gasket for leaks I cannot hear or see. Been working like a dog so I haven't had a evening to mess with anything on the jeep. Hoping to tomorrow and Saturday evening.

More clues.. Last night, sitting in the cold it started up. Had a high but normal idle for about 5-7 seconds. It acted like it was gonna be fine. I didn't touch the gas and then it starting running rich and idling irratic again. Idling below a grand and at times 500 while backfiring.
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-26-2013, 03:15 PM   #51
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
Backfiring is very distinct. That is when it is firing the cylinder when the intake port is open and it goes through the intake. Are you sure you had backfiring? That can only be a timing issue.
Que89YJ is offline   Reply With Quote
Unread 12-26-2013, 09:42 PM   #52
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
Well seems to me it is back firing. The AIT was soaked when I pulled it and the intake definitely smelled like gas. Spark plugs were wet too. Is it possible for the timing to be off only when it's cold? I know that sounds stupid but I mean this is the mighty 4.0 not the 4.2 haha. In that case.. Would a camshaft sensor be to blame? See if I take out the AIT and warm it up with a hair dryer and put it back in, it starts and idles fine even if the rest of the jeep was cold. Maybe a combination of problems and that just "tricked" the PCM into a decent air/fuel mix in that open loop. ?
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-26-2013, 11:41 PM   #53
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
Lean fault is a cracked exhaust manifold 9/10 times. If you are flooded that is likely what you have. The ecu thinks there is too much air and dumps fuel to save the engine. Read the fuel pressure look for the exhaust leak
Que89YJ is offline   Reply With Quote
Unread 12-29-2013, 03:04 PM   #54
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
Checked for leaks in the intake with carb cleaner.Good there. Exhaust leaks I found, tightened up the collector to down pipe bolts. Can't believe I overlooked them. They weren't too loose though. Checked for leaks with smoke and a match. No more leak at that connection. Found a good size "finger" hole where the down pipe turns to go towards the catalytic converter. Could that cause the o2 to read funny? That's some distance away. Also note, again I do not have a muffler on the jeep. I unplugged the o2 and got a 21 + 51 codes. So that tells me the o2 is ok because with it plugged in it is only saying 51. I bled the fuel line after shutting it down. Seemed like air and fuel came out. It was a strong foam string sort of. Waited a couple minutes. Bled it again. More gas and more air. Repeated this 10-15 times over the course of 20 minutes and now I just have air coming out.... It should be nothing coming out, as in zero psi. I haven't gotten my hands on a gauge yet. Believe it or not I've been stupid busy. I also stuck my ear to a screw driver on the injectors. Each one at idle is firing the same rate and making the same noise. At smooth idle. Haven't heard them at rough idle. Does this help decipher any other faults?
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-29-2013, 05:06 PM   #55
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
The 51 won't clear until you disconnect the battery for 10sec. Reconnect and drive it for 20 minutes. That's long enough for it to go into closed loop and use the o2 sensor. Anything after the sensor doesn't matter.
Que89YJ is offline   Reply With Quote
Unread 12-30-2013, 08:33 AM   #56
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
Put the new o2 sensor in. Drove for over 45 mins. Different speeds stop and go,65 mph cruising. No exhaust leaks. And ran really well. Only hesitated "lost power" accelerating once. No lean codes or otherwise. This morning, Being cold... Still a rough start but didn't smell as rich, I was able to flutter the gas and get it warm faster. Within 2 minutes aside from 5-10 which it used to be. The coil was off a parts jeep and could be weak, I checked the wires for shorts and grounding wires also coming from the alternator. Those are all ok. So now... On to checking the fuel psi.
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-30-2013, 09:45 AM   #57
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
Check your intake air temp sensor with a meter. I bet it's bad.
Que89YJ is offline   Reply With Quote
Unread 12-30-2013, 10:16 AM   #58
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
I had replaced it. Maybe the pigtail is bad though? I have the print out for the ohm on it. I'll take a gander
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote
Unread 12-30-2013, 11:06 AM   #59
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,831
no..it sounds like it is driving better now
Que89YJ is offline   Reply With Quote
Unread 12-30-2013, 11:53 AM   #60
2jeeps1stang
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2009
Location: NW Indiana
Posts: 259
Yup. Just a rough idle on cold start.I'll mess with the fuel the weekend when I have time.
__________________
87 yj wrangler, 4.0, lifted, 33s. Slowly taking jeep 'roids.
75 cj5 304, Fiberglassed, 4:56, lift, 35s
73 cj5 built 401
2jeeps1stang is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.