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TheTopher
Well-Known Member
Hey guys, so I have already fixed this problem but I didn't find a whole lot of direct help on a stumbling startup or a misfire during startup when I searched for it. So I'm making a quick write up of my experience to help anybody else who has a similar problem.
So my truck was running alright, abeit a little rough when I bought it. So I went to do a tuneup, starting with plugs and wires.
I went with motorcraft for both the plugs and wires. I installed them fairly easily, I did not have to remove anything except where the intake tube meets the throttle body. I read about people having to remove the top half of the intake manifold and that is totally unnecessary. Big thanks to 95rangerboy and his thread about the extended spark plug socket. Made the job VERY easy.
Anyway, I got them all in, I went to start my truck back up and it started to stumble, almost sounded like it was about to die. Exactly how an engine with a misfire sounds. Then after about 15-30 seconds it would run just fine, with a very small stumble every now and again. So I double checked all my connections and still no dice, and the engine was NOT throwing a code.
I looked up the dual spark plug system on here and found that only one set of plugs is used to start the truck and then the second set clicks on. Very good information. That would explain why it only stumbles when I start the truck, there is a misfire in the first set of plugs but when the second set engages it makes the affect of the misfire much more subtle. So I figured I could disconnect one set of plugs to see if the truck starts and isolate which set is used for starting. I disconnected the set closest to the back of the truck and left the other set connected. Viola, the truck kept stumbling long after it had been running for a minute or two. So I started disconnecting wires at the coil pack until I found one that DIDN'T make the engine run worse. Bingo, the problem was isolated to cylinder 1.
So I switched the new wire out with the old wire. The problem still didn't go away. So I switched out the new plug for one of the old ones. Bam, problem solved. Took the bad plug back to autozone and got it switched for a new one. Threw it in the truck and everything's good now.
So that's my writeup, I hope someone down the road will find it useful. Take care guys.
So my truck was running alright, abeit a little rough when I bought it. So I went to do a tuneup, starting with plugs and wires.
I went with motorcraft for both the plugs and wires. I installed them fairly easily, I did not have to remove anything except where the intake tube meets the throttle body. I read about people having to remove the top half of the intake manifold and that is totally unnecessary. Big thanks to 95rangerboy and his thread about the extended spark plug socket. Made the job VERY easy.
Anyway, I got them all in, I went to start my truck back up and it started to stumble, almost sounded like it was about to die. Exactly how an engine with a misfire sounds. Then after about 15-30 seconds it would run just fine, with a very small stumble every now and again. So I double checked all my connections and still no dice, and the engine was NOT throwing a code.
I looked up the dual spark plug system on here and found that only one set of plugs is used to start the truck and then the second set clicks on. Very good information. That would explain why it only stumbles when I start the truck, there is a misfire in the first set of plugs but when the second set engages it makes the affect of the misfire much more subtle. So I figured I could disconnect one set of plugs to see if the truck starts and isolate which set is used for starting. I disconnected the set closest to the back of the truck and left the other set connected. Viola, the truck kept stumbling long after it had been running for a minute or two. So I started disconnecting wires at the coil pack until I found one that DIDN'T make the engine run worse. Bingo, the problem was isolated to cylinder 1.
So I switched the new wire out with the old wire. The problem still didn't go away. So I switched out the new plug for one of the old ones. Bam, problem solved. Took the bad plug back to autozone and got it switched for a new one. Threw it in the truck and everything's good now.
So that's my writeup, I hope someone down the road will find it useful. Take care guys.
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