At least do a poor man's compression test.
Turn engine by hand and note the compression "peaks".
There should be 2 noticeable peaks for each rev of the crank pulley.
2 revs for all 4 cyls.

If you get 4 similar feeling peaks, move on to air leaks, carb problem.

If only 3 peaks...........

 

Do a compression or a leak down test first.

 

Will do
I should be able to get my hands on a compression tester for friday