Ruff running after valve cover replacement

Joined
May 25, 2014
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32
Did the valve cover gasket on my 94 and now it seems like it's running on 5 cylinders.
Also did plugs, wires, cap, and rotor while I was there.
I've gone over it 3 times and even swapped back to old cap and wires. Everything is plugged in.
It idles rough and sputters when driving. Definitely feels like it's not running on all 6. No CEL codes either.
I'm out of ideas.
 
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Apr 14, 2016
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Did you pull the spark plug cables one at a time to figure out which cylinder isn't firing? Did you check that the injector connectors are fully seated and that each one is clicking?
 
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May 25, 2014
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32
I didnt mess with the injectors so I would guess they are in the same state as when I started. I am gonna go pull the plug wires one at a time now. I will double check the intake hose but mine is in pretty good shape for its age.
 

LandLocked93

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Did the valve cover gasket on my 94 and now it seems like it's running on 5 cylinders.
Also did plugs, wires, cap, and rotor while I was there.
I've gone over it 3 times and even swapped back to old cap and wires. Everything is plugged in.
It idles rough and sputters when driving. Definitely feels like it's not running on all 6. No CEL codes either.
I'm out of ideas.
You did just replace the valve cover gasket? OEM gasket?
Not the PCV and grommet too? Are they vintage OEM?
To what value did you torque the cover bolts after replacing the gasket?
Did you notice if the bolts were 'hand tight' when you took them out?
 
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Nov 9, 2012
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Olathe, KS, USA
1) Did you disconnect the battery during this time? If so, the computer needs to "reset and relearn". This takes multiple times (as many as 30 start/stop cycles) for it to be fully reset.

2) Did you replace the spark plug tube seals?

3) Did you use an OEM gasket? Did you torque the VC bolts to 12 lb-in?

4) Did you get all the vacuum hoses reconnected under the intake manifold and on the EGR?

5) Did you tear the intake hose during this replacement? This would allow significant air issues.

6) Did you disconnect the AFM in the intake hose by removing the two screws and tugging on the wiring harness? This is a serious no-no on a 93-94.

Everything you describe points to the AFM and vacuum leaks.
 
Joined
May 25, 2014
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32
Thank you gummycarbs! Found #4 not firing. Had spark. Looked closer and found the injector unplugged. I did not remove this during my install. Pulled the throttle body off to get a better look, seems the previous owner had broken the tab off the connector.
 
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Apr 14, 2016
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Oregon
Woo!

I could swear I've read threads about injectors coming unplugged for no apparent reason. I'm beginning to think they're sentient. And jerks.
 
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Jan 29, 2022
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Location
Freeport, Florida, USA
Depending on the year of your rig I think @NLXTACY sells OEM replacements.
Nice! I hadn't found that vendor yet. Cool stuff. I like the packages like the vac and vapor kit, among others. Seems a little more expensive than some places but those packages and the practical advice and instructions (like linking to the pin removal tool in the injector connector page) are cool. Thanks!
 
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May 31, 2010
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2,638
Thank you gummycarbs! Found #4 not firing. Had spark. Looked closer and found the injector unplugged. I did not remove this during my install. Pulled the throttle body off to get a better look, seems the previous owner had broken the tab off the connector.
Just replace all 6 connectors while you are doing it. Once you figure out how to pop them off it is easy.
 
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Gilbert, AZ
Nice! I hadn't found that vendor yet. Cool stuff. I like the packages like the vac and vapor kit, among others. Seems a little more expensive than some places but those packages and the practical advice and instructions (like linking to the pin removal tool in the injector connector page) are cool. Thanks!

No worries. I am glad you found what you needed, the great thing about Joey at Absolute Wits End he has tons of OEM parts and parts that someone said damn that is a good idea and he made it. A prime example of that is his inner seal/bearing driver for the 80 series land cruiser. His driver allows you to push the bearing/seal in a little farther so it rides on part of the axle that is not worn from years of use.
 

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