89 Chevy truck I'm having a issue with no spark. I have the module out everything has power but as soon as it's lay back down to the distributor power cuts out when it's grounded.

Sounlike the pickup module in the HEI distributor is not working . Check the red wire for power and a good connection

I don't think 3 months makes stale gas, maybe year old gas, but not your short time. And if not mistaken, I think you have throttle body injection on an '89 chevy, although chevy always was a little behind the curve on new improvements to cars. hint, hint.
The computer has everything to do with it. it controls ignition timing, it controls spark, it controls the fuel pump and the injectors. Since it won't start with starter fluid or gas, next step is to look into the ignition system. Check for spark on a couple of spark plug wires. If you have a blue, snapping spark, you can assume your ignition system is working well enough to start the engine. Take a spare spark plug or pull one of your plugs from engine, attach the plug wire onto it, and lay the plug on a metal piece of the top of engine-the spark plug hex and threads is the natural ground for the plug, so if you lay the threads on a metal piece, or hold it tight against a steel bolt, you can observe the spark jumping the gap, and no danger of getting shocked. But if you hold it, just in case, wear a glove or wrap a heavy cloth or rag around the wire. Remember, a blue energetic spark has to be seen to verify good ignition. Oh yes, you need a helper to crank the engine over while you watch for spark. If no spark, and you have a distributor, check the coil wires output at the end that connects to center top of distributor.Pull it from distributor and hold the metal end terminal no more than 1/4 inch from a ground source, a bolt or the frame, or an engine bracket. Helper has to crank the engine over, and watch for good blue spark. If no spark there-ignition: coil, crank position sensor (or maybe a pickup coil inside your distributor-same function), ignition control module, computer, and all the associated wiring.
If coil has spark, but none at plug wire ends, inspect closely the distributor cap and rotor. not passing current or shorting out there.
So the basics are, to run, the engine needs gas, air, compression, and a timely spark.

Could be ignition switch is bad, does distributor ever have power going to it?

yes, ign module.

Have you checked the HT leads? The main lead from the coil - take off a spark plug lead and plug that into the coil insted and see if you can get it to spark to the engine, if it will spark with this lead then the main lead is bust. also...There is a condenser on the ignition, it prevents the spark from going anywhere but the plugs, if this has failed you will have a weak intermittent spark - heres what it should look like (attached to the distributor or very close to it) - http://www.rockauto.com/catalog/raframecatalog.php?catalog=233&partnum=84UX&a=UK233-84UX - click the "i" button to get a bigger pic - make sure yours is properly connected before you get a new one. It's incredibly cheap so may as well replace it + its 21 years old and counting and probably the only original part of the ignition.

did you change the computer controlls too

Check and see if u have spark to the plugs, if you don't replace the TFI ignition module on the distributor and the pickup inside the distributor, the dist must be removed to do this coil pickup replacement.
Comment posted on Mar 04, 2009 also check the fuel pressure if the spark is ok, the ignition is the ,most common issue. Comment posted on Mar 04, 2009 also check the fuel pressure if the spark is ok, the ignition is the ,most common issue.

1989 20yrs old ,well it must have an ignition module ,but as i have never seen a truck like this i couldnt tell you the location ,its either by the coil or inside the distributor ,could evan be screwed to the outside of distributor .Iam sure this is your problem

i believe you will have to disassemble the distributor and shaft assy to replace. honestly may be cheaper and easier to replace whole distributor (minus module) with good rebuilt. will at least save time and frustration if that is in fact what is wrong with it

Are you sure its no spark? It could also be a bad fuel pump... have you done a check for spark? If you pull one of the plugs out and lay it on the engine block and turn the car over a few times you don't see spark, or it just doesn't fire when it cranks?

I suggest you perform this test. If you see spark I can almost guarnatee that its a fuel pump issue.

Try this test if the one above passes. Pull off the intake hose (big thick hose attached to the throttle body) and spray in some starting fluid. If it cranks and tries to run but then dies, that suggests that there is no fuel getting to the motor which is usually a bad fuel pump as relays and fuses usually don't burn out on their own. These two tests should narrow it down pretty significantly. Hope this helps! Good Luck!