Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Jumpy idle/Gas in oil

Thread Tools
 
Search this Thread
 
Old 10-24-2016, 08:39 PM
  #1  
Junior Member
Thread Starter
 
Turtle_XJ's Avatar
 
Join Date: Aug 2016
Location: Louisville, KY
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Engine: 4.0
Default Jumpy idle/Gas in oil

Long story short, I hydrolocked my jeep. It's a 1998. I got it up and running again and ever since it has a high idle on first start, fluctuating idle +/- 25rpms,bad mpgs, sooty plugs, gas in oil and rich smelling exhaust. The codes I have thrown are "lean in bank 1" and for my 02 sensors which I assumed was because of the way the jeep is running.

I checked my fuel pressure and it's will steady sometimes but on idle it jumps between 40-49psi very quickly. It smooths out when throttled up.

I have changed the TPS, MAP, fuel pump, 02 sensors and cleaned the IAC and throttle body. My injectors aren't leaking. I didn't feel the need to check compression because it showed no signs of having a bad HG or head that I'm aware of but I guess that's next. I figured the gas in the oil is due to it running so rich it's washing the cylinders.

Have any suggestions?
Old 10-25-2016, 10:29 AM
  #2  
Junior Member
 
dac612's Avatar
 
Join Date: Jun 2016
Posts: 40
Likes: 0
Received 0 Likes on 0 Posts
Year: 1993
Model: Cherokee
Engine: 4.0
Default

That fuel pressure fluctuation won't cause your issue BUT it may be a sign that you have a vac. leak somewhere. I'd start there. sounds like you covered most of the common stuff.

The only other thing bothering me is your description of gas in the oil. How much gas are you talking about? Just a rich running engine isn't going to cause a whole lot of fuel in your oil. But a leaking injector would.

Also does your model have the FPR on the fuel rail?
Old 10-25-2016, 12:05 PM
  #3  
CF Veteran
 
Firestorm500's Avatar
 
Join Date: Apr 2009
Posts: 4,734
Likes: 0
Received 9 Likes on 9 Posts
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
Default

Cracked ring? Piston? Scored cylinder walls?
Old 10-25-2016, 03:36 PM
  #4  
Junior Member
Thread Starter
 
Turtle_XJ's Avatar
 
Join Date: Aug 2016
Location: Louisville, KY
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Engine: 4.0
Default

Originally Posted by dac612
That fuel pressure fluctuation won't cause your issue BUT it may be a sign that you have a vac. leak somewhere. I'd start there. sounds like you covered most of the common stuff.

The only other thing bothering me is your description of gas in the oil. How much gas are you talking about? Just a rich running engine isn't going to cause a whole lot of fuel in your oil. But a leaking injector would.

Also does your model have the FPR on the fuel rail?
Maybe half a quart in 50 miles

What do you mean the fuel pressure fluctuation won't cause my problem? The lack of pressure would cause a jumpy idle right?

FPR in mine is in the fuel pump and it was replaced with the whole assembly I got out of a parts jeep.

Last edited by Turtle_XJ; 10-25-2016 at 03:44 PM.
Old 10-25-2016, 03:43 PM
  #5  
Junior Member
Thread Starter
 
Turtle_XJ's Avatar
 
Join Date: Aug 2016
Location: Louisville, KY
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Engine: 4.0
Default

Originally Posted by Firestorm500
Cracked ring? Piston? Scored cylinder walls?
Shows no signs of any of those besides the gas in the oil. No noises ,ticks or blowby. I'll do a compression test tomorrow I guess to confirm.
Old 10-25-2016, 06:30 PM
  #6  
CF Veteran
 
Waynerd's Avatar
 
Join Date: Jan 2015
Location: North canaan Connecticut
Posts: 1,469
Received 26 Likes on 26 Posts
Year: 01, 99, 98, 98,98
Model: Cherokee
Engine: 4.0
Default

Did you happen to check the fuse for the 02 sensors? If they were submerged it could blow the fuse.
Old 10-25-2016, 06:44 PM
  #7  
Junior Member
Thread Starter
 
Turtle_XJ's Avatar
 
Join Date: Aug 2016
Location: Louisville, KY
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Engine: 4.0
Default

Originally Posted by Waynerd
Did you happen to check the fuse for the 02 sensors? If they were submerged it could blow the fuse.
I think I did. It was fine.
Old 10-25-2016, 11:08 PM
  #8  
CF Veteran
 
Firestorm500's Avatar
 
Join Date: Apr 2009
Posts: 4,734
Likes: 0
Received 9 Likes on 9 Posts
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
Default

Originally Posted by Turtle_XJ
Shows no signs of any of those besides the gas in the oil. No noises ,ticks or blowby. I'll do a compression test tomorrow I guess to confirm.
Gas in the oil is a sign of possibly one of those.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 



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