cant figure it out:misfire cylinder 3

[ezekiel.8g]

i got a 97 2.3l with a misfire on#3, ive checked the packs , injectors, replaced plugs and wires, compression test was good( all were between 140psi-150psi).a buddy told me it might be a burned valve and to do a leakdown test, but compression is good and im not smoking from the tail. wierd thing is sometimes it runs fine,no misfire, i got the misfire p0303 after i checked and replaced air filter,and worn hose that sits on tb that was pluged;lead nowhere,along with the p0303 i somtimes get p1131 but not always.thats where im at right now im hoping someone can give me some help, im stuck.

 

[maverick1970]

I've got a '98 2.5L and was having the same problem with the cylinder 3 misfire check engine light. I had more symptoms that lead me to believe it was a head gasket problem (wet cylinder 3 spark plug, white smoke/steam coming out of the tail pipe, loss of power). So I took my head off this past week to change the head gasket but instead I found cracks between the valves on all 4 cylinders. You might have to get into the engine to get down to the problem like I did.

http://www.therangerstation.com/forums/showthread.php?t=68390

 

[modelageek]

Ezekial, You said there was a plugged hose that went to nowhere. is it possible that is the hose that goes to your pcv valve have you checked the pcv valve.I am not sure how you checked the packs, I have heard that they can have small cracks that are hard to detect. I wonder if you swapped the packs and developed a misfire on a different cylinder you would know it was the pack..... lets see what some other peeps think

 

[ezekiel.8g]

thanx for the input guys.i dont have any smoke,white or black,coming out the tail pipe,temp dosent fluctuate,and the misfire comes and goes,its most noticable at idle while driving it seems fine.i switched the packs around to see if misfire would jump on another cylinder.the hose is suppose to be capped off for what reason i dont know,i looked into it in my haynes manual and it shows a pic of tb with capped of hose.im aiming towards doing a leakdown test but my haynes manual doesnt describe the procedure it says to take it to a shop.can any one descibe to me how to perform this test?like i said ranger was fine till i replaced air filter.

 

[modelageek]

I don't know how to do a leakd test. If it was my truck because it is cheal easy and should be done. I would clean the maf, clean check pcv and get gasket for IACV and clean that. Also I would double check the airfilter since it started there

 

[modelageek]

Any chance you jarred the maf/connection when you changed the airfilter

 

[ezekiel.8g]

ill check all that again, thanx again ,ill try and do a search on other ranger forums for leakdown test instructions.i really dont think its mechanical because the misfire comes and goes.

 

[Dragonclaw]

I know you said you switched the coil packs so the problem probably doesn't lye there. But, on my 1996 ranger about 5 years ago I had the same problem, except it was the #2 cylinder, and it was because one port on the coil pack was not firing. Get a good pair of insulated Channel Lock pliers and pull the #3 plug wire off the pack and hold it over the hole and check for spark, that's how i found my issue.

Now this may not help, or you may have checked it already but I figured id put in my 2cents.

 

[modelageek]

I think when the OP said "he switched the coil packs" I think he meant they are the originals he just changed from front to back. now if he gets a misfire on a different cyl he knows it the coils. I know the OP thinks it is not these issue but I have a feeling it is, the coils, something to do with changing the airfilter, a vacuum leak, pcv, etc. It will be interesting to see what it is.....

 

[TonkaMan]

I have the exact same truck with the exact same problem. Cylinder #3 misfire. I've tried everything. I changed the coils, plug wires, the fuel injector for that cylinder, fuel filter, and even the engine computer. If you find the problem please let me know. My mechanic spent 6 hours on it and couldn't figure it out. His solution to change the engine computer solved it for about 2 weeks.

 

[modelageek]

I have the exact same truck with the exact same problem. Cylinder #3 misfire. I've tried everything. I changed the coils, plug wires, the fuel injector for that cylinder, fuel filter, and even the engine computer. If you find the problem please let me know. My mechanic spent 6 hours on it and couldn't figure it out. His solution to change the engine computer solved it for about 2 weeks.

you might consider starting a new thread. Did you Change the plugs? what brand plug did you use?

 

[modelageek]

I have the exact same truck with the exact same problem. Cylinder #3 misfire. I've tried everything. I changed the coils, plug wires, the fuel injector for that cylinder, fuel filter, and even the engine computer. If you find the problem please let me know. My mechanic spent 6 hours on it and couldn't figure it out. His solution to change the engine computer solved it for about 2 weeks.

you have a 93 right? I thought the 93 had an ignition control module? is that what you changed? or did you change the actual PCM?..........I know in my truck I don't have a ICM. My the ICM duties are built into the PCM.......but I think you have an ICM

 

[kimcrwbr1]

Did you pull and sand all of the grounds especially coil and computer make sure all the connectors are good and the pins are pushed all the way in.

 

[Bryan22]

i'd start by checking the coils with a multi meter, just swapping the packs is making the assumption that at least one of them is working perfectly. this might not be the case.

What king of plugs and plug wires are you running? I had a problem with a brand new set of wires leaking all kinds of spark. Make sure you don't go to cheap. And if you're not running autolite/motorcraft plugs i'd seriously consider changing them again.

If everything checks out this is kind of a long shot, but i've heard of people having problems because of the routing of the plug wires. try to keep them all as seperate as possible and try to keep all wire intersections to a minimum. good luck!

 

[Bryan22]

haha i just realized this thead hadn't been opened since december....