Low compression cyl has 20 lbs of compression.

Place a spark plug tester in your number #1 ignition lead and confirm spark.- No spark = possible ignition module failure if spark from coil is present.

Test the fuel line pressure for 12 PSI.for throttle body fuel injection systems on 1987 to 1995 - If reading is low replace fuel pump. If reading is zero lbs check relay.

Compression test for acceptable compression.

If you have spark, fuel and compression, static time the engine and try again to start the vehicle.

PS: If your vehicle is a standard shift you have a clutch safety switch and a column mounted ignition switch that should also be considered.

Here is some more info that may help:


How to Test the Fuel Pump on GM TBI Fuel Systems How To Check Engine Compression GM 3 5L 4 2L

Behind the left suspension mount in the engine bay, see pic.

http://ww2.justanswer.com/uploads/supermechanic/2009-09-26_181650_relays.gif

should be 80 - 110 lbs cfm per cylinder +

1993 3.2l Gas V6 engines, right>? double posted too.
the torque page is clear, read that yet, seem not.
seem 123 is correct, but
2.8L V6, GM
3.1L v6 GM
or 3.3L V6 Isuzu.
as you can see there are 3 , V6 engines.
an not posted yet, even second post.
above poster used 4 cyl engine and is wrong. BILL
now answered, 2 twice,
before working on any engine, know whats there first.
and win.

100 psi per cylinder is way too low--should be in the vicinity of 150-165 per cylinder
back firing indicates wrong firing order and as you have replaced the plugs etc check that you have the leads on the correct plugs in the correct order
the timing for the engine should be around the 10 degree btdc and not tdc

long shot guess, but a dam good one is your coil is bad. I'm 99.9 percent sure. Or coil wire bad

check your fuel pressure and then check fuel pressure regulator fuel psi should be around 35 lbs

fuel regulator?

Wow! thats verry low miles for an 88. Check the fuel pressure at the injector. If the pressure is low the filter could be clogged or the pump is not putting out enough pressure. Replace both if the pressure is not up to par. also check the fuel relays.

Firing order is 1-6-5-4-3-2 cyls. # 1-3-5 on drivers side front to back and cyls. # 2-4-6 passenger side front to back.