Misfires

[technobandit96]

Ok. I have a explorer that has a misfire problem. I last changed the spark plugs and wires and it has not fixed the problem. Any guess where to start next?

 

[C420sailor]

Sure it’s a miss? Any codes? When does it do it?

A lot of people with the 4R70W transmission have reported what they thought was misfiring...it was really torque converter shudder.

 

[J_C]

Hook it up to an OBDII code scanner to get codes for which cylinders are misfiring. If more than two (which could just be a bad coil, so you could check for spark at each coil) then I'd also check fuel rail pressure. You can also check for power to the injectors and see if unplugging suspect injectors makes any difference.

Does it do this while idling, or only under load, or both?

Which engine? It'd be good to list that in your sign or your profile panel on each post.

 

[410Fortune]

what engine?
How many miles?

Check fuel pressure
97 should have 36-42 psi at the rail

Any loss of coolant?

 

[technobandit96]

I have a scan tool that I can use but I have a hard time reading the codes from it. I got the tool from Autozone and when I start it up it gives me a bunch of dollar signs and that doesn't seem like P and C codes to me.
The last time I changed the spark plugs was the last time that had any knowledge of losing coolant from the vehicle. I also just updated the mechanical side of the explorer. I found out all of the transfer case numbers and transmission numbers as well.
As in terms of maintenance, I just gave it fresh oil but did not do an oil change, yet. It needs one with transmission flush and fill with a new gasket and fliter.
When it misfires, the car gets up to 1500 and 2000 miles per rotation and then all of a sudden it drops.