1997 GMC Yukon 350 R motor. Cranks but will not start. Getting spark. Ether doesn't help. Has a new fuel pump (within the last 6000 miles)

Kelly, could be a few issues, security lock out, crank sensor, fuel pump fuse/relay, faulty new pump,faulty ignition switch, etc. Attached links may help you diagnose the crank no start issue you are having.
Check the attached links,video,instruction and guides, Good luck
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Crankshaft sensor SHOULD throw a code so if you have an OBDll code reader and your Service Engine Soon light is on that could answer that question. You could always ground a plug wire to see if your getting spark. If it's the fuel pump, many times you can smack the bottom of the fuel tank pretty hard a few times with an open hand and get it to work for again for a short period of time. For the purpose of diagnosis you give it a try and if it starts, then you can pretty much be sure it is the fuel pump. Though don't trust it if you're at home. It might make it a block, it might make it 20 miles but it's going to fail again shortly.

That's often a sign of a failing check valve in the fuel pump. Try this. When you turn the key to RUN, the fuel pump activates for 2-seconds to boost any lost pressure. Try turning the key to RUN, then OFF and repeat three times. If the engine starts right up, you probably need a new fuel pump. The real test is called a leakdown test where the shop throws a pressure gauge on it and leaves it overnight. If it loses more than 5-10-psi, the check valve is shot. Can't be replaced separately .

you have spark at the plugs ..thats something

spray stay you mug
into the throttle body see if the motor will cough

tank needs draining and have fresh fuel
fuel pump has a filter and fuel relay

crack the fuel line connection to the rail to see if there is fuel reaching the rail and correct pressure

if sitting 6 years.. not being run regularly
do a compression test
lifters may be stuck
rings may have lost tension

You should try removeing the fuel filter its under the drivers door mounted to the frame then crank the engine to see if you are ectaly getting fuel flow to the rear of the filter from the pump if you are then replace the filter but honstly the most likely cause is the pump is no good these pumps last about 10 years there were problems with themand the new ones have many upgrades that correct these problems .If you can fix it with the filter you will still have to think about replaceing the pump in the near future if its the orgenial one if you want to keep the vehicle running

You didn't say if it crankes over if it dose check for spark. If you have no spark replace your distriburator modual. Also check for fuel pressure no fuel pressure may need a fuel pump in fuel tank hope this helps CJ

ok make sure you have good fuel pressure
you must have good spark must fire a spark tester
if all that is good then check compression
and don't use STARTER FLUID on a GAS ENGINE it can blow a hole through the piston
hope this helps

WHEN YOU REPLACED THE FP DID YOU OR THE DEALIERSHIP REPLACE THE FUEL FILTER MAYBE YOUR PROBLEM ....

get your self a fuel pressure tester, hook it up to the fuel rail, you should get at least 30 psi with key on, 30 to 45 psi with engine running.

Check for a bad distributor cap and or rotor..........a bad cap and or rotor can caues firing (cross fire)across the terminals and introduce spark to the wrong cylinders at the wrong time.......
hope this helps.....good luck!