2001 4.0 misfiring

[bigjerm]

Hello Rngstation,

I'm having some problems that are baffling a mechanic. After driving a couple hours fairly hard on my ranger with 130k(bad idea I'm guessing), I lost power on the freeway and the cel started flashing, so i got off and pretty much limped a few more miles home. I started it up a half hour later and cel was gone and seemed to be back to normal. Anyways, I take it to a shop to check it out, and they pull some codes that indicate some isssue. There was like 5 so i just dropped it off. A ignition coil, coolant sensor, some wires and plugs switched later and still misfiring on #5. Mech then checks compression on the #5 and it was fine. He points the timing instrument or some device and tools around the injectors and doesnt find the issue. Anyways, 2 days of that and he is baffled. I"m out 150 and he says he can go deeper if i want..but it's gonna cost$ He thinks maybe cracked intake or the computer. I do have some Mexican gas still in the tank, but the station was a reliable one. Could bad gas cause a misfire in one cylinder? This mechanic i don't know, so any suggestions would be greatly appreciated. thanks.

 

[myranger26105]

sounds like the problems i was with my 03 but my problem was all of my cats were clogged up so might want to check that

 

[modelageek]

Hello Rngstation,

I'm having some problems that are baffling a mechanic. After driving a couple hours fairly hard on my ranger with 130k(bad idea I'm guessing), I lost power on the freeway and the cel started flashing, so i got off and pretty much limped a few more miles home. I started it up a half hour later and cel was gone and seemed to be back to normal. Anyways, I take it to a shop to check it out, and they pull some codes that indicate some isssue. There was like 5 so i just dropped it off. A ignition coil, coolant sensor, some wires and plugs switched later and still misfiring on #5. Mech then checks compression on the #5 and it was fine. He points the timing instrument or some device and tools around the injectors and doesnt find the issue. Anyways, 2 days of that and he is baffled. I"m out 150 and he says he can go deeper if i want..but it's gonna cost$ He thinks maybe cracked intake or the computer. I do have some Mexican gas still in the tank, but the station was a reliable one. Could bad gas cause a misfire in one cylinder? This mechanic i don't know, so any suggestions would be greatly appreciated. thanks.

we need details. we need the exact codes. when you say "some wires and plugs" what does that mean?..........bad gas could cause your issue but most likely not, however ....I would immediately add a large bottle of Techron(any auto store sells this) and new premium gas for starters.....get us the codes!!

 

[bigjerm]

Thanks, I'll get the codes. I think it was p0305, but after fixing the coolant sensor the mechanic just showed me the computer getting a negative number on one cylinder with the rest at zero. Sorry I don't really know how to describe the details of what the mech is doing better, I'm far from being one myself. The wires he tried new ones, and he just switched the plug out with a new one at with the corresponding cylinder that is misfiring, which did not work, and he tested the compression there as well which was fine.

 

[naford]

How far did you drive with th CEL flashing?

 

[Ranger44]

With a cylinder misfire, and the tuneup being orig.....the first thing I'd suspect would be a plug or wire also.

Next culprits, fuel injector, compression, etc.

But the fact that it was low on power after lots of hard driving, and running non U.S. gas......it makes me think the catalytic converters are contaminated.

But I'll wait to see what the codes are before jumping into any other conclusions.

 

[06RangerXLT]

plugs, wires, cats, injectors or fuel filter is where id start. begin with the cheap parts.