95 SSEI
My scan tool says that I have a miss on cylinder #4. The car misses especially at idle and low speeds. I decided to start all over in my search since I changed the LIM and a few other things and I don't want to overlook something obvious. And yes the LIM was bad. I pulled the plugs before the LIM swap and one of them was bridged from fouling. So today I pulled all of the plugs and took the coil packs off to check them again. I noticed that a couple of the bolts that held the coil packs down were barely hand tight. I had deliberately not tightened them too much and they may have vibrated loose. I did not have a torque wrench at the time. I do have one now so that won't happen again. There is another issue though. The plugs have only about 300 or so miles on them. They look good but the #4 plug is clean. Too clean. It looks brand new. Here is what has me concerned. The #5 plug. The tip is bent. I remember hearing a pinging after replacing the LIM. I know it is possible that something found its way into the cylinder even though I tried to be careful and from what I understand it could even have moved to another cylinder. I plan to use a small vacuum extension to get as deep into the cylinders as possible before I reinstall the plugs. I also plan to check the cylinders with a magnetic pickup tool. I plan to recheck the plug wires, then injectors and a compression check next. So any ideas on what else could have happened to the #5 plug? And why is plug #4 so clean?

If possible see if you can get a bore scope. Check to make sure there is no damage in the cylinder.

X2.

Number 4 might be an injector not firing or the plug not firing. After you get the cylinder scoped out, then run the car and use a mechanics stethoscope and listen to the #4 injector. You should be able to hear it open and close (ticking).

Ok, I'm not familiar with a bore scope. Can I rent one somewhere?

Most tool rental places should have one.

Great, thanks guys.

That #4 doesnt look like it'* seen a spark in it'* life. That just too fresh looking.

Yeah and the camera doesn't do it justice. I expect to find an electrical problem with the injector since I am getting a spark to the plug. That plug was put in about a month ago when I found that #4 cylinder was missfiring. I had just changed the plugs and wires the week before.

So, I tested the coils. The secondaries were all 5.5k ohms. The primaries were .8, .6, and .6. The last one would drift down to as low as .3 then go back up to .6 or .8. It mostly ended up at .6 or .5. Should I replace that one? I reinstalled the coils and plugs. Tested the #4 electrical connector to the injector with a bulb , it is getting power. Started it up and noticed that it no longer misses at idle even when I hold the brake and ease the rpm'* up to close to 2000. I'm not out of the woods yet though. Now whenever I give it enought throttle to move the boost gauge towards 0 it starts to bog down. It wasn't doing that before, only missing at idle and low rpm. All that is gone now. Probably from the closed gap on the #5 plug. Oh, I wasn't able to get my hands on a borescope yet. No one that I called rents them and Napa had a sale on one for $158.00. I did vacuum out the cylinder and I ran a magnetic pickup tool inside and didn't find anything. I am going to test the boost actuator. I replaced the boost control solenoid a couple of months ago. Any thoughts?

The foot on the BCA is pointing straight up when the engine is idling. It drops down when I unplug the vacuum line so It looks to be working properly.