mis-fire for one cylinder below 2000rpm, HELP?

[dasfinc]

Bumped from the engine form since no traffic

the title pretty much describes it,

I have a 2000 4.0 OHV 4X4 with 152K on it, and it is throwing a CEL for Cyl1 misfire.

I replaced the plugs and wires, cleaned the MAF, MAF Plug, Coil pack, Coil pack plug, and it still hasn't gone away.

2 other things I've noticed, that I am unsure if they are related or not,

1) The truck smells a bit 'sulfury' but I just replaced brake pads and bearing and haven't gotten around to replacing the warped rotor yet, but the smell seems to come from the opposite side of the truck *pass side is the smell, driver side front is the new pads*

2) Also, the Both cats make ALOT of crackling/pinging sounds after I turn the truck off (pass side of truck also), I know it will ping a bit, but its sizzling inside of both of them, which seems unusual.

Suggestions? Can a single cyl be impacted with a failing coil? Can clogged cats cause a miss JUST below 2000RPM?

 

[BlackBII]

Can you 'feel' or hear the misfire or are you just going off the check engine light?

How often does it misfire? How's the idle, is it shaky at all?

 

[dasfinc]

Can you 'feel' or hear the misfire or are you just going off the check engine light?

How often does it misfire? How's the idle, is it shaky at all?

I can feel it, and am fairly mechanically inclined.

its constant, you can feel it at idle, and under load below 2000RPM.

 

[modelageek]

I can feel it, and am fairly mechanically inclined.

its constant, you can feel it at idle, and under load below 2000RPM.

have you changed the fuel filter and added some techron to the tank....

 

[dasfinc]

have you changed the fuel filter and added some techron to the tank....

I forgot to mention that.

I also ran a bottle of seafoam through the intake via brake booster, and tossed a bottle of the good lucas injector cleaner in the gas tank, and then topped off the tank.

It feels a BIT better after I did everything, but it is still there.

I didn't change the fuel filter, but I may have a spare brand new one sitting in my garage so I might as well. I HIGHLY doubt that is the cause *May contribute* as it is a single cyl misfire, and not a random one.

I am leaning toward coil pack or sticking/bad injector, any easy ways to test/confirm either without having to pull off the manifold?

And thank you everyone already also for the input, I greatly appreciate anything to help knock this out. I plan on towing with this truck in 2 weeks, and then plan on driving it all winter

 

[straycat]

My 99 was doing the same thing. It felt like a weird tug as I accelerated from a stop sign or a traffic light. It had just a bit of a rough idle and I checked the plugs and found a fouled plug... (#3) and I went ahead a put in all new ones. It has been fine since then.

 

[dasfinc]

My 99 was doing the same thing. It felt like a weird tug as I accelerated from a stop sign or a traffic light. It had just a bit of a rough idle and I checked the plugs and found a fouled plug... (#3) and I went ahead a put in all new ones. It has been fine since then.

Thats what I had hoped it was, so as I mentioned in the first post, I replaced all 6 and the wires, and cleaned everything in the process, but no love

 

[dasfinc]

I have a Chiltons for Explorers... but not for the rangers...

Anyone have a picture/link on how to test a coilpack for the 4.0 OHV? And does anyone know what the lb injector it runs? I have some spare 96 V-8 injectors.... if they are the same?

 

[straycat]

Thats what I had hoped it was, so as I mentioned in the first post, I replaced all 6 and the wires, and cleaned everything in the process, but no love

Yes I saw that you replace the plug wires and plugs. I forgot to mention that I also put in a new fuel filter and replaced the MAF sensor the next week since I saw that it was about due for an induction cleaning. I do the induction cleaning every other year.

How about the ignition coil pack wires? How are they? I went ahead two months ago and replaced all the wires on mine since I bought my 99 Ranger brand new and have had it for 11 years now. I bought all of them on Ebay and the difference is like night and day. The truck is pulling so much better now. It did need the new plugs awhile back but the wire replacement was really a great choice.

The only thing that I would really recomend you do is take it to a shop and have them put it on the scope. I had mine scoped last year and there was no issues (or they would have told me to make a few extra bucks). It did cost me $39 for the engine scope...but I feel this was a worthy cause since I do take good care of my truck!!!

 

[dasfinc]

How about the ignition coil pack wires? How are they? I went ahead two months ago and replaced all the wires on mine since I bought my 99 Ranger brand new and have had it for 11 years now. I bought all of them on Ebay and the difference is like night and day. The truck is pulling so much better now. It did need the new plugs awhile back but the wire replacement was really a great choice.

The only thing that I would really recomend you do is take it to a shop and have them put it on the scope. I had mine scoped last year and there was no issues (or they would have told me to make a few extra bucks). It did cost me $39 for the engine scope...but I feel this was a worthy cause since I do take good care of my truck!!!

Coil pack wires looked good, HOWEVER, I feel like its 'missing' something.... There is a ground wire with a grey 'slide on' clip that isn't attached to anything.... I thought that normally went to the radio fuzzy reducer or whatever....?

Shops in my area are all highway robbery, mostly 'well off' area, so shops are hurting for money because people who had/have car problems go to the dealer, or buy a new car, or bought one during C4C.

 

[adsm08]

A bad coil can cause a miss on a single cylinder.

 

[sloth69mustang]

check the compression on the cylinder first. i had a valve stick once that caused a similar problem and it was at 112k. so i could the heads off and had a machine shop clean them for like 175 bucks and now my truck is sitting on 180k and runs like a champ. if compression is fine then look at spark and fuel. could be an injector

 

[dasfinc]

Coils all tested good, and I found my fuel filter *Had one laying around*

So that leaves one thing honestly, and now that I think about it, it makes perfect sense, I think injector #1 is sticking. 'pinging' cat because there is alot of unburnt fuel *Sulfur smell*, and the injector is still working 'electrically' so the CEL wouldn't say "Injector"

Had the same thing happen in my old 4 cyl, so I'll pick up a replacement later this week and knock it out and pray.

 

[sloth69mustang]

seriously check compression before you go off buying an injector just to make sure. bc if the exhaust valve is not closing all the way you could be getting a little sound tho the exhaust. and will cause a misfire for sure

 

[dasfinc]

seriously check compression before you go off buying an injector just to make sure. bc if the exhaust valve is not closing all the way you could be getting a little sound tho the exhaust. and will cause a misfire for sure

I didn't have the issue when I bought it. It sat for 3 months prior to me buying it, and had little/no gas in it when I picked it up. It got suddenly and progressively worse, I replaced the plugs/wires/seafoamed, and it got a LITTLE better.

What year was your truck that had a stuck valve? I'd be REALLY impressed if a 00 4.0 got a stuck/sticking valve out of the blue like this. More importantly, and more 'to the point' If it needs head work, I rather sell the truck than put the time into it as I just don't HAVE time to put into it.

Also, if compression was an issue, wouldn't it have power loss throughout the powerband?