idle getting worse

[Pete J]

Ive had a problem for a while but now its bugging. Ive searched the foroum with no sucses. So today i was checking my spark from the coil pack and when i take the wires off with truck running from the coil pack 1 thru 5 have great spark and number 6 is real weak i have to hold the wire alot closer to coil pack. ive tried fixxing everything else but i still have a miss. check engine light is on and the code reader says miss on #6 . hopefully one of you can help, Thanks alot. really just need to know how to tell if coil pack is bad

 

[Rearanger]

I'd remove and inspect plug #6 then do an OHM test on plug wire #6.

"Normal plug wire resistance should be 10,000 to 15,000 ohms per foot of length. If it is higher, it is probably bad."

 

[Pete J]

Ive done all that replaced plugs, wires, and any thing else i could think of. The only thing i havnt replaced is the coil pack. but its when i unplug one wire at a time from the coil pack with truck running you can clearly see the sparks jumping accept for #6, very little spark is arcing you have to hold wire real close unlike all others which have giant spark. so it seems to me to be the coil pack, but i hate spending $100 bucks if its not the problem. so is their a way to test coil pack

 

[Rearanger]

but i hate spending $100 bucks if its not the problem. so is their a way to test coil pack

Switch it with another and see if the problem moves.

 

[Pete J]

tried that too. and im sorry, the code reader says # 6 is missing and the one with the week spark is #3

 

[Rearanger]

the code reader says # 6 is missing

Hot engine compression test.

 

[Pete J]

do you mean my engine could be getting hot. or do a hot engine compression test?

 

[Rearanger]

do a hot engine compression test?

Miss may not be electrical. Doesn't hurt to check basics first, then go from there.

 

[Pete J]

this is the part that gets me confused, is my truck sometimes runs great like today. check engine light went off, it was idling great for the most part it was running great. this happens alot, just this time the bad running lasted longer than usual. its got about 137,000 on it, nothings been changed beside air cleaner, oil ,spark plugs & wires. & the crankshaft sensor, because i was told that it could be the problem. I just dont know what it could be so next will be compression check.I see alot of other posts were people are posting problems with rough idle and it seems no one can figure it out. I hope i can, and i bet its the same problem everyone else has. thanks

 

[Pete J]

fixed

Turns out it was the coil, On a guess i bought one on ebay brand new for $36.00 and free shipping. Talk about a good deal. But all my guessing cost alot of money tried plugs wires crankshaft sensor. nothing worked till i put on new coil, so just thought id let everyone know. Thanks

 

[SandyOne]

Thanks to all who had the problem of rough idle before me for all the suggested fixes. Hate to have to buy something else after 13 years of breaking in the ranger.