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Unread 07-10-2014, 10:50 AM   #1
94HOCHEROKEE
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Help!!! Is My motor blown??

I just got finished changing the valve cover gasket and now my exhaust is blueish with a heavy smell of fuel. Its Just like my Lawn mower. I dont have a cat as i'm in the process of replacing it.
Could lack of cat cause this? Or is there something I can check on the fuel rail??

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Unread 07-10-2014, 01:10 PM   #2
93gc40
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Yes lass of cat could cause this. Blue pipes signify LEAN condition. Lack of cat going to make O2 sensor think you are rich and will cause the ECU to lean the fuel mix.
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Unread 07-10-2014, 02:03 PM   #3
94HOCHEROKEE
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can I reset the ecu to fix this?
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Unread 07-10-2014, 02:13 PM   #4
Timo_90xj
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Quote:
Originally Posted by 93gc40 View Post
Lack of cat going to make O2 sensor think you are rich and will cause the ECU to lean the fuel mix.
What?

The O2- sensor behind the cat (if vehicle is equipped with it) is only for analyzing if the cat does it's job, and to illuminate the CEL if cat is malfunctioning. Rear O2- sensor does NOT affect air/ fuel mixture in any way.

The forward O2- sensor doesn't know if there is a cat converter installed or not. Even with no cat the forward O2- sensor will give correct readings to PCM for as long as the sensor itself is in good condition, there are no engine issues going on, or there is no exhaust leak before the O2- sensor.


To the OP:
Blue smoke means you're burning oil. Black smoke and smell of gasoline indicates you're running rich. Verify if you actually are burning oil or not. If not, your engine is ok. If you're burning oil, it can be because of multiple reasons. Since you've had the valve cover off, are you sure the crankcase ventilation system is hooked up properly and functioning as should?
Running rich can also be caused because of many things, but the lack of cat will not cause it. It is something else. You may have knocked loose a sensor connector or have forgot to plug in something you unplugged during your valve cover gasket change.
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Unread 07-10-2014, 02:43 PM   #5
94HOCHEROKEE
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^^^ thank you. I reset the Ecu with no luck.
I am going to have to go through a engine schamatic to make sure everything is hooked up.... thanks again
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Unread 07-11-2014, 06:47 AM   #6
cruiser54
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Quote:
Originally Posted by 94HOCHEROKEE View Post
^^^ thank you. I reset the Ecu with no luck.
I am going to have to go through a engine schamatic to make sure everything is hooked up.... thanks again
Be sure the integrity of the hose/tube from the throttle body/manifold to the MAP is perfect.
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Unread 07-11-2014, 09:52 AM   #7
SSellers
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Eh, sounds like you just pulled one of my moves and left something unhooked. Besides, if anyone could blow up a motor just by changing a valve cover gasket I'd like to claim ownership of that title. I've gotten into the habit of taking a notepad out with me and as I remove any bolt/connector/hose/etc I write it down, then mark it off when it's put back. Started doing this after doing some axle bearings in a car, sealing everything up, picking up a paper towel to wipe my hands, and having the axle c-clips tinkle out of the paper towel onto the floor.
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Unread 07-11-2014, 12:48 PM   #8
94HOCHEROKEE
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Quote:
Originally Posted by cruiser54 View Post
Be sure the integrity of the hose/tube from the throttle body/manifold to the MAP is perfect.
I was out there inspecting around the valve cover and noticed one of the rubber elbows that connects to a vacuum switch was almost rotted through. The boot is connected to a sensor on the manifold, its the first sensor on the manifold closest to the front end. I siliconed it untill I can get a replacement. Still need to figure out what sensor it is to get a new boot for it.

I will check all the lines connecting to the throttle body. I noticed that it looks like my injectors are leaking because of the dirt ring around where they connect to the motor. I was thinking of replacing those too w/ 2.4l neon injectors. Could those cause the rich mixture
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