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You need to figure out what you do not have that an engine needs to run. What is the fuel pressure at the fuel rail? Do you have spark when cranking the engine? Are the fuel injectors operating? Do you have ample compression? When you figure out what you do not have, that will tell you what you need to fix.
check see if you getting spark if not.have vechicle code scan could have faulty ECM .faulty camshaft sensor and crankshaft sensor.make sure engine has been tuned up.replace fuel filter change spark plugs and wires. before engine can run need fuel and spark.either one not working car will not crank.
check fuel pump fuse and relay also the fuel injection fuse and ecu fuse, if they are ok remove the back seat and you will see a cover remove the cover and check for voltage at the pump plug and ground, you hear the pump work if not need new pump
start by checking the fuel pump fuse and relay. will the fuel pump run for a few seconds when you turn the key to the run position? If so you may need to replace the crank position sensor. When this goes bad the engine will turn over and start, but only run for a second or two then die like its out of gas.
If you do not hear the fuel pump coming on and the fuse and relay check out good then you will have to see if there is power going to the fuel pump. if power is present at the fuel pump plug then the fuel pump is bad
If it cranks strong then it's probably not the battery/alternator/starter. Check the battery terminals to make sure they're clean. Cars need 3 things to start and run: fuel, spark, and compression. If it's just cranking it might be the fuel filter and/or pump. Could also be a fuel pump or PCM fuse or relay. Check your manual to find the locations of those in your fuse panel or in the fuse box under the hood. When you turn the key to on, before trying to start it, you should be able to hear the relays clicking. If you put a finger on it you should be able to feel it click (you'll need a friend for that). You should also hear the fuel pump pressurize when you turn the key to on before starting. It sounds like a humming sound that lasts about 3 seconds. If the relays don't click, that's probably you're problem. And if they do click and you can't hear the pump, then you'll probably need to replace the fuel pump and filter. If you hear the pump pressurize then you probably have electrical or spark problem. Hope that helps!
Did the engine just quit going down the road? or was it parked and then would not start? Did it have fuel before you replaced the filter? Did you check all the fuses in the fuse box. I think 2 of the fuses is marked ECM, check both Fuel pump relay? swap it with another relay in the fuse box. You should hear the pump come on for 2 seconds when you turn the key on, do you? If not as you are cranking the engine have someone rap on the bottom of the fuel tank with a mallet or block of wood, or hammer and see of the pump will run. If that gets it running, the pump is bad and will need replacement.
You are looking for the constant control relay module- ( CCRM ) see below. The pump will be located inside the fuel tank.Most of the time , its the pump and not the relay but, it wouldn't hurt to check the relay out. Teh relay is housed in the CCRM. Its located behind the engine coolant reservoir.
Is your security light flashing? If your Tahoe has the factory ant-theft system, if the security light is flashing while you are cranking your anti-theft system has been activated. It is common for the Tahoes to wear out the ignition lock assembly, lock cylinder and the ignition switch(electrical) which is attached to the lock assembly. I have replaced all three parts with great success and solved the no start problem on several GM trucks.
The most common problem with these vehicles is the fuel pump. The pump should run for a few seconds when you turn the key on before you crank the engine. If you don't hear the pump run, go to the fuse/relay box under the hood. Look at the diagram on the inside of the lid and locate the fuel pump fuse and relay. Check the fuse to see if it is blown put it back if OK or replace it. Unplug the fuel pump relay and use a paper clip to jumper across terminals #30 & #87 where the relay plugs in. If the fuel pump starts running, you should be able to hear it run at the back of the vehicle, where the tank is. If you don't hear the pump running, hit the center of the tank dead-center with a rubber or wooden mallet. If the pump still doesn't run, see if you can get to the wires going to the fuel pump and wiggle them. If you hear the pump run, try starting the engine. If it starts, replace the relay, if that was the problem or the fuel pump AND relay if the fuel pump was the problem. WARNING! WHEN YOU UNPLUG THE PAPER CLIP. IT MAY BE HOT!!!
The fuel pumps AND connector are big problems with GM trucks. If you replace the fuel pump(which is located in the fuel tank), use only the factory pump which you can buy at your GM dealer or an auto parts store that sells Delco parts. If the fuel pump used the small square four-pin electrical connector, replace it with the fuel pump. The latest GM/Delco fuel pumps will come with the new plug which you MUST change over as it is now a flat four-pin connector.