I have a 93 Mazda mx 3 v6. I HAVE fuel, spark, and compression, timing marks all line up, will crank but not start what will cause this no start condition? Note: I replaced the disty, crank sensor, fuel filter, throttle position sensor.

2.3 L MZR L3-VDT DISI turbo I4
contradicted at cranks no start and RPM zero.
the starter spins the engine 300 RPM cranking but most dash tacho's are dead below 500. sure.
Cranks ,then starts and then runs and for more than 10 seconds.
that is a serial process on engines. it may start and stall at 10 seconds.

no crank has 6 to 8 causes
cranks fast but will not start has up 50 causes.
we can not hear your starter spin here, nor see crank spin fast.
we are blind and deaf (<< ask us is not easy/)
lets go with cranks fast and will not start.( i chose it)
well , key on and the IMMO lamp must nut be Unhappy per the lost users guide,in the glove box.
the easy answer is this, using only physics, tests. using TOOLS

1: engine is dead. and compression or leakdown tests fail, compression below 150psion one or more cylinders.(4)
2: next is spark is 1 or more cylinder.s(all 4) a test,
3: bad fueling , non, or bad fueling, and pump sounds mean little none. pump pressure matters, another tool;. PSI

watch,do and then ask better questions.
cranks means only that the starter works and spins the engines crank shaft fast (keep the battery charged at all times on any dead car)
the fuel dribble test only matters if DRY..a pressure gauge test is the only tool to use. for spec pressure.(ask)

https://youtu.be/064Ilsz8Fzg

Check for a blue snapping spark on 2 or 3 plug wires(or all of them). If you get good spark, then ignition is likely not the problem. A weak or sporadic spark could be a bad coil or coil pack, or a bad ignition module (the ignitor).Check the coils with a volt-ohmmeter per the specs for your car. The ignitor can be tested at a parts store.
If spark is good, check fuel filter, fuel pressure, check timing marks on crank pulley and cam marks, Try a little starting fluid in the air intake and see if it runs for a moment. If so, then it's likely a fuel delivery problem. If no change, then it's likely an ignition circuit problem.
Good luck.

NE1 SENSOR

Engine cranks normally, but it does not fire:
You turn the key to start and hear the starter motor crank the engine, but when you release the key, the cranking stops and there is silence. This means that the battery and starting motor are working properly, but the engine is not firing. If you continue cranking the engine over in this way, the battery will eventually run down and will need to be recharged, but the battery and starter are not the cause of your problem.
There are a number of causes for this type of no-start condition, the most common being that you are simply out of gas. Assuming that you have fuel in the tank, you will need to go through a series of tests to determine what is causing the problem. The testing procedure is as follows:--- Spark:---------An easy way to test for spark is with an inexpensive spark tester. This is a device that is readily available at most auto supply stores. You use it by simply holding it next to a spark plug wire. If you see the neon lamp flashing while someone cranks the engine, then you have spark and should move on to checking for fuel. If there is no spark, or a very weak spark, you will have to replace the spark plug or the coil pack.It has to be checked. Fuel:
First step here is to listen for the fuel pump running inside the gas tank. When you turn the key to run, you should easily hear the pump come on, run for a few seconds to build fuel pressure, then turn off. If you do not hear it, it could mean that the fuel pump or circuitry is bad. (Fuel pump failure is a common problem). Fuel injected cars are very sensitive to proper fuel pressure. If the pressure is off, even by a few pounds, it will cause noticeable performance problems, or a no-start condition. To check for proper fuel pressure, you will need a fuel pressure gauge that is suitable for your type of system.Or you can also get the fuel pressure tested at local car garage,If fuel pressure is low then its a fuel pump and fuel filter related problem. Compression:

If you know that you have spark and fuel, the next step is to check for compression. For this, you will need a mechanic's grade compression tester that will screw into a spark plug hole. You will need to remove the spark plugs and use the compression tester to test the compression on each cylinder. If the compression is very low on all cylinders, that is a sure sign that the timing belt (or timing chain depending on the engine) has failed and will have to be replaced.

-------------

This troubleshooting will let you know the problem.Thanks.

my mx6 died on me one day,same thing it would keep cranking but would not fire and start towed to a garage spark tested.NO spark changed distributor and problem fixed

I have a funny feeling that you have the belt on wrong. I know, you said the marks line up, but a compression check is easy and just confirms everything. Failing that, could you have the plug wires on wrong...I'm wondering if spark is occurring on the compression stroke or the exhaust stroke, and all this could come back to if the cambelt is on right as well.

Bottom line; if you have spark, fuel and COMPRESSION, it'll run.

fuel pressure regulator it is located on the spider pump behind the throttle body

VSS or vehicle speed sensor aka cam sensor or crank position sensor. Test the battery and alternator. You should also check for blown fuses, bad wires and grounds on a car as old as yours. If you find it's getting spark and fuel after further testing, check the timing belt. It could have slipped or broke even if it was changed recently so either pull off the cover or at least do a compression test.

If the above information is correct.
1. Good Compression
2. Good Spark & Proper timing
3. Good fuel Pressure, injector pulse , injector spray, & fuel quality( no t contiminated)
4. Proper & clear air intake into engine
Then the likely cause would be a restricted exhaust. disconnect the exhaust at the manifold, and retry starting engine. keep me posted, we will make her run!

Make sure you are getting gas and spark, they are a few ground wires that come off of injector harness that if they are not grounded will cause injector NOT to pulse re-check wiring and get back to me. Good Luck