#5 cylinder not firing

[muddinbronco87]

I just put a new engine (70k miles) in my 1994 Explorer. The engine starts great but idles a little rough and you can tell it has a miss when your going. I've checked the codes and got some EGR stuff which I'm going to replace but thats it. I've replaced the coil pack, the #5 wire, and spark plug but still nothing. You can tell that its the #5 because when the wires not hooked up it'll run the same as when it is hooked up but if you pull a different wire it'll start running rougher.
Any help would be great.
Thanks

 

[Tbars4]

...It may be more useful if you post all the codes you are getting...

...I think it is odd that #5 on two coil packs is not working...:scratch:

 

[Michiganbear]

time for a compression test I think, or check the injector for #5 and its wiring (maybe not getting fuel into the cylinder).

since the coil pack fires 2 cylinders at a time, it pretty much rules out the harness from the coil pack to the EEC.

 

[muddinbronco87]

Yeah I'm going to do a compression test. It's getting fuel but I don't know if its enough you can tell that their's gas on the plug but its not super wet. How can I check the injector? The codes I'm getting are 335 and 336 I also started getting a 136 code which I think is being caused by an exhaust leak before the O2 sensor.
Thanks

 

[muddinbronco87]

Also is their a chance the intake gaskets could cause this if they were leaking?
Thanks Again

 

[Tbars4]

...Found you a couple reads on your codes...

...code 335...
http://www.explorerforum.com/forums/showthread.php?t=210110&highlight=335
...code 336...
http://www.explorerforum.com/forums/showthread.php?t=143497&highlight=336

 

[marragtop]

Try switching # 5 wire with a different cylinder and see if the code moves to the other cylinder.

 

[muddinbronco87]

What do you mean by switching the wire so that the code changes?

 

[Tbars4]

..:scratch:...I think he means the injector wiring...

 

[Masterd]

What he meant was, take one of the spark plug wires from a firing cylinder and put it on #5 and see if it fires then....if it fires with #4's wire on the plug for example, then it could be the coil pack, if not, youve got bigger issues.

 

[Tbars4]

...I might of thought that too but I was hoping he read the first post where it stated...

"I've replaced the coil pack, the #5 wire, and spark plug but still nothing. "

 

[Masterd]

Id have to go for compression test...as long as its got spark and fuel.

 

[muddinbronco87]

Alright looks like I'll do a compression test. Sometimes it feels like it clears up thats why I wonder if it has something to do with the injector. Is their a way to test the injector? Also I'm wondering would water from the headgaskets being shot in the previous engine cause the cat. converter to go bad because it has a smell like what has been explained that it'll smell like.

 

[Explodr94]

To check an injector, you need to check with a mechanics stethescope or an old fuel line hose and a screwdriver. Put the stethescope on the injector, you should hear a steady ticking, you can easily compare the ticking with the other injectors. You should also check the fuel injector connector for volts. I believe that test is described in the Haynes manual,(maybe not).

 

[muddinbronco87]

Got it figured out ended up being a bad injector. Thanks for all your help .

 

[Tbars4]

...Congrats on it being something simple...:biggthump