For about 22 years my 1988 truck has always started. Today it would not. Battery seems OK and turns the motor normally, has fuel. Suddenly it just won’t spark or splutter or anything.
Having never had a problem I don’t know where to start looking. Suggestions?
You need three things in each cylinder to start the engine:
1: fuel
2. spark
3. compression
One of those three is probably not there. Use process of elimination to determine which one it is.
To continue…
Primary culprits would be:
Fuel pump
Ignition module
Fuel filter
Here’s the first thing I would do: while someone is cranking the engine, stick the inductive pickup coil from a timing light on a few of the spark plug cables to see if you’re getting HV.
First check for spark. If there is no spark the testing goes in a certain direction.
If there is spark, the testing goes in a different direction. Next thing is to see if it will start and run (ever so briefly) on ether (starting fluid).
I’ve got the year and the make, but I need the exact model (e.g C1500, K2500, S10, Suburban, etc.) and the engine size (e.g. 4.3, 5.0, etc.) to accurately determine relevant details.
Air. You gots to have air.
Does the engine sound normal when cranking? Does it turn slower, or faster than normal while cranking?
When you say it has fuel, do you mean the pump is running, or there is fuel in the tank? Are you sure there is fuel in the tank? And I don’t mean does the gauge show fuel, do you know for a fact there is fuel there? Gauges can break.
Did you buy gas in the last day or so? If yes, you need to take a sample and look for water.
does the fuel pump run when the engine is cranking? (Listen at the filler neck when someone cranks the car, you should hear it buzz.
Does the engine have spark?
I agree with a possible bad fuel pump or an ignition failure, I’m not so sure about a fuel filter.
Well, right. Fuel = gas + air. 
Never mind I reread the post.
In addition to what size engine, you might need to figure out what kind of fuel system you’ve got. I think they had finally done away with carbs by '88, so you’ve either got TBI, which has two fuel injectors sitting right on top of the engine (you should be able to see them when you take the lid off the air cleaner), or it’s MPFI, which has a fuel injector for each cylinder.
If you do have TBI (which IIRC, most of them did at this point) one thing you can do is have someone else turn the engine over and actually look at the fuel injectors to see if they’re squirting fuel or not.
One of your electrical cables has worn out and is not getting the charge across. Probably one of the batter cables or the ignition cable from the coil to the distributor, assuming.
Wow, that’s quite a confident diagnosis! Especially considering that we don’t even know what engine it has. I hear the coil wire was a real problem on the 6.2L’s, though.
This thread is absolutely oozing testosterone! 
While cranking the engine, have someone pound on the gas tank with a rubber mallet. I’ve been surprised at how often this has worked when I’ve tried it. Sometimes the fuel pump can get stuck in some way, and the pounding jars it loose.
OR,
The pounding will cause a poor ground to complete the circuit. Old vehicles can have numerous grounding problems.
Fuel pump.
Very confident, and my money is on this one. Take it to the dealer and they’ll have it diagnosed and fixed in an afternoon.
every form of combustion requuires air fuel and compression. for an internal combustion engine to statr and maintain its self spark timing and fuel must all be present. air and gasoline mix makes up the fuel. compresson is a given but with out the three main components of an internal combustion engine all the compression in the world simply makes a very strong vacuum.
Our zombie overlords suggest you consult a dictionary for the meaning of “combustion.”
Check the seventh Fetzer valve.
You’ll need some Prestone anti-freeze and some ball bearings.
Either that or the bypass hose to the Metzler valve.