engine will not start

[1993blazerlt]

I have been trying to start my friends 89 blazer. I have times the engine checked the spark and know it is getting fuel. I also did a compression check and the gague moved between 90 and 120 psi and made one jump up to 150. This was on a cold engine because the engine has not run in a while. The engine ran before but ran very ruff. After i timed it it ran better but then it just stoped running all together. This is really getting me mad what could it be?

[bvr775]

runing rough is the key to this puzzle.. *89.... that would be a 2.8 right?

to strt you will either need a second person or a remote stater button. you can pick these up at any parts store or sears.
compresion:
90 is a bit low(you definatly have a problem here, but nothing that would keep it from running) . 120 to 150 would be in the right range. recheck the cylender you got 90 on then squirt some machine oil in the plug hole and recheck it. if you get an increase you need rings. if it stays the same check valves. the compresion tester should have jumped around allot on each clylender as you tuned over the engine. if you got a steady reading you may have a worn cam lobe. (this will keep it from running)

fuel:
try eather(starting fluid). this will not work on closed fuel systems like mfi and cpi engines, but you have a trottle body or carberator(I belive the carborated engine was still offered as an option in 89 on GM trucks).make sure you not flooding it(this is not impossible if you have injector, but pretty unlikely). check your fuel pressor

check the ingnition module
Snap an inductive clip timming light on #1 and see if it's fireing on the line on the harmnic balancer tdc. yes you can roughly set timming even if the engine dosen't run. #4 should fire at the tdc also.

if you have a multimeter check the coil, wires, and pickup coil. just because it's getting fire dosn't mean it's getting fire at the right time.
the haynes manule has a complete and well writen section on testing these componets.

[Matt 4.3 TBI]

Quick note, all 88+ Blazer/Jimmy are 4.3.

How long has it been sitting? Have you checked the fuel pressure? If it has been sitting a long time there may be water or sediment collected in the tank. Also, if it is spraying good fuel, but won't turn over, chances are it will be flooded after the 3rd or 4th attempt. To switch the computer to 'clear flood mode', hold the pedal to the floor, then turn the key to start for a few seconds. This will force out the excess fuel, and if that's the only problem, will usually get it started.

If the fuel is good, then the problem lies with igniton. Follow bvr's good advice for that.

[1993blazerlt]

i have no idea how long it sat but it was probley a good amount of time. I checked the pickup coil and modual and the coil and wires are brand new. i have all ready timed it with a light but it is hard to get an exact reading because the timming tab is missing from the timing chain cover