Just a note: You can get a cheaper comp. tester…its like any gauge…wel, anything. The cheaper it is the less accurate. BUT, I’ve used a cheap one for year and for shits n giggle compared to a higer price one that my friend had, it was like 10+/-psi diff.
Also, have u checked ur plugs?
**Leak down test is gonna be the deal breaker. get the leakdown test done.