1997 AWD 5.0 rough idle, bucks when accelerating under 2000rpmc

[Ozz1967]

As the subject. 97 Explorer 5.0 AWD.

I can't figure it out. Tonight the car surged while cruising at accelerating from a stop light bucking hard. Once over 2k rpm's it's fine and pulls fine over 2K rpm or in 2nd gear. When I slow to a stop in gear it has a rough idle. In Park it's smooth but as soon as I get it in drive the rough idle returns.

Any thoughts on where to start? Oil level is fine, Trans fluid is ok. Not sure where else to start.

 

[97-5.0]

Clean the IAC, check fuel press
Should never go below 30 psi

 

[Ozz1967]

CLeaned the IAC and MAF. Went to Oreillies and pulled the codes. Only code thrown is "Cylinder 4 misfire"....

 

[Ozz1967]

I get the misfire causing the rough idle but the bucking/stuttering has me thrown.

 

[97-5.0]

Ide replace the #4 wire and visually look at the plug, if it needs a new plug then get all 8

Very common for wires to break down and melt from being so close to exhaust

If it's not a plug or wire then #4 injector is spent, been here and done it

 

[Ozz1967]

Ide replace the #4 wire and visually look at the plug, if it needs a new plug then get all 8

Very common for wires to break down and melt from being so close to exhaust

If it's not a plug or wire then #4 injector is spent, been here and done it

I replaced the plugs, cap and rotor last summer, just got lazy and didn't finish the plug wires. If the plug wires don't fix it and the injector is bad, do I want to replace all of them?

 

[97-5.0]

I replaced the plugs, cap and rotor last summer, just got lazy and didn't finish the plug wires. If the plug wires don't fix it and the injector is bad, do I want to replace all of them?

Don't have to, if you have the funds I would!

Rockauto is best price, only legit ford injectors

 

[97-5.0]

Before you spend money, look at the plug, it should be melted or show other signs of misfire if the injector is bad

 

[Ozz1967]

Before you spend money, look at the plug, it should be melted or show other signs of misfire if the injector is bad

Ok, the plug was new last spring so it should still look pretty good unless the injector made it bad. I guess I'll know more when I pull it.

 

[koda2000]

I'd just try replacing the one spark plug and plug wire. Cheap and easy enough to do. How did the old plug look? If it was pure white the the injector may be bad (or not receiving the signal to spray).

BTW: What brand and type of spark plugs did you put in there last year?

 

[Ozz1967]

I'd just try replacing the one spark plug and plug wire. Cheap and easy enough to do. How did the old plug look? If it was pure white the the injector may be bad (or not receiving the signal to spray).

BTW: What brand and type of spark plugs did you put in there last year?

The old plugs I pulled out had all kinds of buildup on them. White chalky substance that was flaky but hard. They looked to possibly be the original plugs in the truck. Most plugs had less than 2mm of space between the buildup and the element end on the spark plug. It was really bad.

 

[koda2000]

The old plugs I pulled out had all kinds of buildup on them. White chalky substance that was flaky but hard. They looked to possibly be the original plugs in the truck. Most plugs had less than 2mm of space between the buildup and the element end on the spark plug. It was really bad.

I was asking what spark plugs you put IN when you changed them last year. White chalky build on plugs is usually because your engine is burning oil.

 

[Ozz1967]

I was asking what spark plugs you put IN when you changed them last year. White chalky build on plugs is usually because your engine is burning oil.

Sorry, ACDELCO from Autozone.

 

[koda2000]

Sorry, ACDELCO from Autozone.

A/C Delco should be a decent brand of plug, but what type of spark plug? Copper? Platinum? Double Platinum? Iridium?

Inexpensive copper plugs will not last very long in the Ford wasted-spark ignition system.

 

[Ozz1967]

A/C Delco should be a decent brand of plug, but what type of spark plug? Copper? Platinum? Double Platinum? Iridium?

Inexpensive copper plugs will not last very long in the Ford wasted-spark ignition system.

I don't recall copper vs platinum but I know it wasn't Iridium.