My car had a lumpy idle and I traced it back to a broken vacuum hose. It was the hose that’s attached to the back of the intake manifold that runs to the air filter. You car wouldn’t have that hose but a leaky intake is worth checking. I think we used to spray starting fluid around the intake and see the revs went up to find the leak on our old MG’s and Triumphs.
I performed a compression test today. Results:
#1 155 psi
#2 157 psi
#3 165 psi
#4 162 psi
#5 157 psi
#6 155 psi
Those numbers seem pretty healthy.
High to low readings within 5%? Very healthy, indeed.