Hey all,
So, I've been having random/cyl#1 misfire issues for the past month or two and have done the following to rule things out (P0300):
1) changed out the spark plugs completely... gapped them to approx 0.031, which is what it calls for, and cleared the DTC's
NOTE: when I checked the spark plugs, they looked really GOOD and have been being used for approx 2x months during this whole test...
2) monitored with my scantool and eventually the same code and the same cylinder
3) took wire plug from cyl#2 and used it for cyl#1 and vice versa (NOTE: JUST the wire!!! In other words, I didn't "cross the fire pattern", if you will). The idea is to see if the wire is the cause? Cleared the DTC's.
4) monitored with my scantool and eventually the same code and the same cylinder
At this point, I ruled out the spark plug and the wire.
5) The next thing that comes to mind is cylinder compression. So, I did that today and have the following:
NOTE: compression range for a 2.7L is 127psi-178psi
cyl#1 = 130psi
cyl#2 = 165psi
cyl#3 = 135psi
cyl#4 = 170psi
I checked cylinders 1 & 3, twice and got the same compression readings.
@4WALKER Ryan or anyone else, what would those readings tell you for me to look for for a next "test"? What would cause cyl# 1 & 3 to have those low readings while cyl# 2 & 4 are within range???
Is that what I SHOULD be seeing???
I know that the compression should only be approx 30psi difference between cylinders, which is what it looks like... BUT... I thought ALL cylinders were supposed to be around the same as, for example, 2 & 4??? In other words, for ALL cylinders, SHOULD I be seeing approx 160psi or thereabouts is my main question?
Would a "leak down test" be the next thing to do? I've never done a leak down test before and would be one of the next things I would do research on, but thought I would come to you guys first to get some basic answers or some next steps to take maybe?
I would go to YouTube to further do research on the matter, but I need to know some of the more basic questions that I had just mentioned above.
Thank you guys. Luckily my smog isn't due until next year, but I'm trying to figure this out now instead of last minute.
My compression tool used is a:
Innova Compression Gauge Tester p/n: 3612
Stay safe people and thank you in advance!!!