Spoolin06XT Posted August 10, 2020 Author Share Posted August 10, 2020 So update on my testing today. Checked compression with the oscilloscope and found a minute dip in revolutions. So it took it for a road test while he read the parameters on his Snap On scan tool. Nothing abnormal, fuel trims were good. Bought some plugs and came back to the garage. Performed a clear flood mode and checked compression on cal #4, I got 149psi. Performed a leak down and they were within 3-4 psi of each other. With the car being so hot and being outside in the 95 degree weather I only changed #4 plug. It looked like the original plug and the car idled and drove a lot better. I think I will change the harness, coils and plugs and drive it again. I was able to use a denso but should I switch it to a NGK? I had some slight cylinder roughness in #4. I will post up Feedback Knock -4.00/0.00 Fine Knock Learn -5.02/0.64 Roughness Cyl #4 0/2 DAM 0.875/0.875 So far the car drives with no misses or hesitation. I drove it for over 2 hours and no issues. Could this all have been the result of a bad spark plug/lack of tune up? I was planning of doing a full maintenance and only had the timing belt/water pump done and tune up was next. Link to comment Share on other sites More sharing options...
samuel082799 Posted August 10, 2020 Share Posted August 10, 2020 So update on my testing today. Checked compression with the oscilloscope and found a minute dip in revolutions. So it took it for a road test while he read the parameters on his Snap On scan tool. Nothing abnormal, fuel trims were good. Bought some plugs and came back to the garage. Performed a clear flood mode and checked compression on cal #4, I got 149psi. Performed a leak down and they were within 3-4 psi of each other. With the car being so hot and being outside in the 95 degree weather I only changed #4 plug. It looked like the original plug and the car idled and drove a lot better. I think I will change the harness, coils and plugs and drive it again. I was able to use a denso but should I switch it to a NGK? I had some slight cylinder roughness in #4. I will post up Feedback Knock -4.00/0.00 Fine Knock Learn -5.02/0.64 Roughness Cyl #4 0/2 DAM 0.875/0.875 So far the car drives with no misses or hesitation. I drove it for over 2 hours and no issues. Could this all have been the result of a bad spark plug/lack of tune up? I was planning of doing a full maintenance and only had the timing belt/water pump done and tune up was next.I would get some ngk plugs. Old or bad plugs will definitely have an affect on how the care runs. It seems like you are on the right track, compression looks good, I would check the other cylinders too while you are doing plugs Sent from my Pixel 2 using Tapatalk Link to comment Share on other sites More sharing options...
kzr750r1 Posted August 10, 2020 Share Posted August 10, 2020 Go with NGK in all 4. Just a backup step here... Did you replace the intake air filter? I had forgotten to do mine last year and oh boy the car drives much smoother with a new panel installed. Simple WIX filter may help? Link to comment Share on other sites More sharing options...
Spoolin06XT Posted August 10, 2020 Author Share Posted August 10, 2020 Go with NGK in all 4. Just a backup step here... Did you replace the intake air filter? I had forgotten to do mine last year and oh boy the car drives much smoother with a new panel installed. Simple WIX filter may help? Ok, will get a set of NGK's, the Denso was the only one available at the parts store I was at the time. Yes intake and cabin filters were the first 2 things I did when I bought it, so its about 5 months old. Thanks for that video too, it made the job easier though the engine was hot Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now