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Low compression? Time to rebuild?

dboyle23

Proven Member
297
13
Jun 10, 2010
Chicago, Illinois
I have been building up my gsx and recently installed a 14b w/7cm, 660cc's, and tuned with ECUFlash. Car was running GREAT for like 6 weeks.

Recently I have been getting misfires in cyl #1. I changed plugs and no help. I changed wires to different cylinders and still just on cyl #1. I did a compression test and got the following numbers from cyl 1 to 4: 140, 150, 160, 160.

The weather has been REALLY hot around here lately and I wondered if that can contribute to burning a valve? I don't have a fmic and was getting a few counts of knock, but nothing over 7. Could that be an issue?

I have some hks 264's in my garage waiting to go on, but I figured that with that 140 in there that I might buy a new head and get some nice springs and such and install the 264's. Then later, after its built, toss it on. What do you guys think? Do you think I should do something else? Maybe 272's?
 

Tyeler18

10+ Year Contributor
2,475
205
Dec 16, 2008
Casa Grande, Arizona
Do a leak down test and find out where it's leaking.

Those numbers really aren't bad. My compression was under 100 on all cylinders and my talon still ran before I pulled the motor.
 

dboyle23

Proven Member
297
13
Jun 10, 2010
Chicago, Illinois
Well, it still runs, and runs decent. That misfire is making me scratch my head and makes the car hesitate a lot. I had the injectors in for like 2 months so I don't think it's that.

Could the 140 compression cause the misfire?
 
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