Cylinder 4 misfire... help!

[91xlt]

Ive been chasing around a misfire for a while the code it threw was for a cylinder 4 misfire i changed the plugs and wires 10,000 miles ago with autolite xp103 plugs and carquest wires because it was misfiring then too. that helped for a while now just recently it started again so i replaced the coil pack, didnt help. it misfires when idling and when under a load until the motor reaches operating temperature and i recently noticed it backfiring through the exhaust on rare occasions... its a 2000 ranger with the 4.0 with 114,xxx miles on it. also noticed its using antifreeze somewhere but doesnt seem to be burning any and there is no antifreeze in the oil

 

[RonD]

Sure does read like a head gasket starting to go.
Disappearing coolant with no apparent leak
One cylinder misfiring(than can cause the back fire)

I would start the engine cold, let it misfire for a minute or so then pull all the plugs and see what each one looks like compared to the others, keep them in order of the cylinder they came from.

With the plugs out you may want to do a compression test, see if one is much lower than the others but if its a small leak it may not show up that well.

In this thread there is a DYI test to see if a cylinder gasket might be blown.
http://www.therangerstation.com/forums/showthread.php?t=128430

A bad head gasket doesn't aways lead to coolant in the oil, it can just blow out between cylinder and cooling system.

 

[AngryLepercon]

Might be dumb to say but I have a miss in cylinder 5. Upon pulling the plugs I found a trail down the side of the block of antifreeze Coming from above the heads. As it ran down the block and hit the exhaust of course it burned off so non in the oil. Turned out to be a intake gasket. Replaced the gaskets and valve cover gaskets and it stopped my miss and loss of coolant. Might be something to look into.

 

[91xlt]

i talked to a ford mechanic today at the local dealership and he said the misfire could be a fuel injection problem i made an appointment for him to look at it tomorrow.. good thing about this dealership is they know i prefer to do as much work as i can on my vehicles so he said he'd look into it give me a quote for what it needs n if i feel comfortable with it he has no problem letting me do the work

 

[shane96ranger]

Sounds to me like you may have cracked the plug putting it in. Been there done that.

 

[91xlt]

i pulled the plug it looks fine no weird deposits no cracks. wires arent corroded in any ways and the resistance checked out fine

 

[shane96ranger]

i pulled the plug it looks fine no weird deposits no cracks. wires arent corroded in any ways and the resistance checked out fine

Mine was the same way. Plugs are 3 bucks maybe vs. how much is a diagnostic? It's worth a try IMHO.

 

[91xlt]

they ran a full test on my cooling system, ignition system and fuel system. the ignition and cooling system checked out good i have a dead injector on cylinder 4. time to put my employee discount to use at carquest and tomorrow after work im gonna work on it

 

[RonD]

That is great news.
The no head gasket issue I mean, not the bad injector.

Did they have any guess on where the coolant went?
Or do you think it was a one time level issue?

 

[91xlt]

I think it was a one time issue... now i have all the parts to replace the injector and was wondering what i all need to do and how to do it? i have to get it done tonight and dont want to be messing anything up

 

[armadillon]

Do you have the haynes manual? It should have a pretty clean explanation. If not, I'm sure someone will chime in.

Just remember to depressurize the fuel system of course

 

[Andy D]

The old BMWs love 5.0 injectors. Guys were getting 8 cleaned injectors for 45 $. I have no clue if they will work on smaller motors , but...

 

[shane96ranger]

The old BMWs love 5.0 injectors. Guys were getting 8 cleaned injectors for 45 $. I have no clue if they will work on smaller motors , but...

First off, I'm not exactly sure what you're getting at. Second, from the factory the 5.0 Mustang/Mark VII use the same injectors as some of the 80's BMW's of the 5,6,and 7 series variety.

 

[91xlt]

got the injectors changed seems to run decent thanks for the help guys! if nothing else it brought my fuel mileage back from 10-12mpg to 18ish

 

[91xlt]

i think what andy d was getting at is the 5.0 injectors might work with the 4.oh but with my discount i only paid $38 for a brand new injector and all the gaskets were like $15