A check engine light showed up just as I needed to register this year. The code showed #3 misfire. I pulled the spark plugs. #3 had some carbon but nothing dramatic. If anything, it showed less wear than the other five. I was shocked at the wear on my Autolite XP985 Iridium plugs in less than 50K miles. I don't really have a closeup camera but if I can figure something out I'll post pictures. I pulled the fuel pump relay and the injector fuses and did a compression test.
Here's what I got in two tries:
#1: 95, 107; gap 0.052"
#2: 150, 150; 0.052"
#3: 97, 108; 0.040"
#4: 142, 134; 0.066"
#5: 150, 155; 0.061"
#6: 72, 80; 0.059"
The plugs started at 0.035" gap.
I tried to do a leak down compression test but the crank would move off TDC with 100 PSI inlet. (Should I just replace all but one spark plug?)
I've got new spark plugs and the injector insulator is arriving today for the "infamous" #3 cylinder misfire though I don't really see heat soaking as the issue right now. We're still in winter.
Any advice on what I'm looking at? or what I should look at next? Odds that this engine is toast? Only has about 150K miles on it.
Here's what I got in two tries:
#1: 95, 107; gap 0.052"
#2: 150, 150; 0.052"
#3: 97, 108; 0.040"
#4: 142, 134; 0.066"
#5: 150, 155; 0.061"
#6: 72, 80; 0.059"
The plugs started at 0.035" gap.
I tried to do a leak down compression test but the crank would move off TDC with 100 PSI inlet. (Should I just replace all but one spark plug?)
I've got new spark plugs and the injector insulator is arriving today for the "infamous" #3 cylinder misfire though I don't really see heat soaking as the issue right now. We're still in winter.
Any advice on what I'm looking at? or what I should look at next? Odds that this engine is toast? Only has about 150K miles on it.