99' Jimmy won't start

Hi, I cannot figure out why my wife's 99 jimmy wont start. I have replaced just about everything that controls the fuel or would prevent the fuel from spraying into the cylinders. Before the truck stopped running she noticed the battery light was on and it was spitting cold air out of the vents, its winter here so we had it running for awhile to warm up, anyway, i shut it off to scan it with my scan tool to see if maybe it threw a code. No code so I was like just start it up and see what happens. well it was like it was out of gas. Needless to say we couldn't get it to run. I didn't have time to mess with it. so we left it sit at my in laws and took our other vehicle home. Trying to make a long story short, I replaced the following parts: the spider injector w a new used one out of a running Blazer, fuel filter, cap and rotor, coil, wires, crank sensor. All relays are good, getting a new computer this weekend, and a ignition module, if those don't work i don't know what is wrong, if anyone has any ideas let me know, thank you.

Hi, I cannot figure out why my wife's 99 jimmy wont start. I have replaced just about everything that controls the fuel or would prevent the fuel from spraying into the cylinders. Before the truck stopped running she noticed the battery light was on and it was spitting cold air out of the vents, its winter here so we had it running for awhile to warm up, anyway, i shut it off to scan it with my scan tool to see if maybe it threw a code. No code so I was like just start it up and see what happens. well it was like it was out of gas. Needless to say we couldn't get it to run. I didn't have time to mess with it. so we left it sit at my in laws and took our other vehicle home. Trying to make a long story short, I replaced the following parts: the spider injector w a new used one out of a running Blazer, fuel filter, cap and rotor, coil, wires, crank sensor. All relays are good, getting a new computer this weekend, and a ignition module, if those don't work i don't know what is wrong, if anyone has any ideas let me know, thank you.

Before throwing the junk yard at it.
You need to check for where the problem is.
The 3 R,s for a gas engine to START AND RUN is spark, compression and fuel.
Check for good hot blue spark to all cylinders.
Check for fuel pressure up to specks like 60/66 if v8 or v6.
Ckeck for good injector pulse.
And then see what it is missing.

Like MT-2500 said, all that work without doing diagnosis first?

As he stated, are you getting spark at all the plugs?

Check fuel pressure with a gauge....should be in excess of 60psi....

Make sure there is no air leak between the MAF and the throttle body.......try taking the IAT sensor out of the snorkle...leave it hanging and attached to the harness....with a can of carb cleaner and the long red extension hose attached, stick the extension in the hole where the sensor was......seal the hold with a rag so no air gets in(this gives you a good MAF reading).......open the throttle plate manually......give a few sprays, release throttle plate....wait 30 seconds.....now have someone crank the vehicle while you spray(keep that hole sealed)......if the car starts or almost starts, you have a fuel delivery problem......if it starts and runs......gets to normal operating temp, then shut it off.....reinsert sensor.....if vehicle starts warm, you may have a borderline fuel pump(55-60 psi).....

Do you have a scan tool or a code reader?

One other thing that bothers me, is before this happened, you had no heat.....when the vehicle is cold, remove the radiator cap.....is radiator full? Was the reservoir full? If you are low on coolant, need to find that leak.....

OK, if it starts with fuel, or almost starts, then you have a fuel delivery problem......so it's one of two things......either fuel pressure is not great enough, or the injectors are not firing....just because you hear the pump run, means nothing....need to get a fuel pressure gauge on this and pressure has to be greater than 60psi....if pressure is ok, than the injectors are not firing....crank sensor has to be OK, and ignition module has to be ok if you have spark.....

Like MT-2500 said, all that work without doing diagnosis first?

As he stated, are you getting spark at all the plugs?

Check fuel pressure with a gauge....should be in excess of 60psi....

Make sure there is no air leak between the MAF and the throttle body.......try taking the IAT sensor out of the snorkle...leave it hanging and attached to the harness....with a can of carb cleaner and the long red extension hose attached, stick the extension in the hole where the sensor was......seal the hold with a rag so no air gets in(this gives you a good MAF reading).......open the throttle plate manually......give a few sprays, release throttle plate....wait 30 seconds.....now have someone crank the vehicle while you spray(keep that hole sealed)......if the car starts or almost starts, you have a fuel delivery problem......if it starts and runs......gets to normal operating temp, then shut it off.....reinsert sensor.....if vehicle starts warm, you may have a borderline fuel pump(55-60 psi).....

Do you have a scan tool or a code reader?

One other thing that bothers me, is before this happened, you had no heat.....when the vehicle is cold, remove the radiator cap.....is radiator full? Was the reservoir full? If you are low on coolant, need to find that leak.....
Sorry I didnt explain all my diagnostics before I posted my question. The vehicle is getting fuel to the spider injector but thats as far as it goes. The fuel is not being released out of the injectors from the spider module. This is what makes me believe its the computer and or maybe the ignition control module, which I am going to replace this weekend. I have not checked the antifreeze because I never ran into a vehicle that didnt start because of low coolant so I didnt bother. Anything is possible though I guess. I do not have a fuel pressure tester and am not inclined to spend too much more money on this truck, already into it 400 bucks and no luck. The junk yard is not an option it is a nice truck when its running. The problem is something stupid and simple I'm not finding. again thank you for your replies. also want to add my father inlaw said his buddy had the same problem with his tahoe, they replaced the battery and it fired right up, naturally I thought he was full of it. could this be possible?, the battery in it is almost only a year old and holds a charge so I dont know.

OK, if it starts with fuel, or almost starts, then you have a fuel delivery problem......so it's one of two things......either fuel pressure is not great enough, or the injectors are not firing....just because you hear the pump run, means nothing....need to get a fuel pressure gauge on this and pressure has to be greater than 60psi....if pressure is ok, than the injectors are not firing....crank sensor has to be OK, and ignition module has to be ok if you have spark.....
Ok ill have to locate a fuel tester then, ill let you all know what I come up with, the fuel pump was kinda loud for awhile maybe its about to quit, ugh! not a job I feel like doing but I have a honda accord that we been sharing and the weather is so un predictable we need the 4 wheel drive where we live when it snows..thank you again.

I still didnt get a fuel pressure tester yet check the fuel pump in the truck yet. But yesterday i figured I would throw the new computer and ignition module in it just for giggles, and of course nothing. Leaning toward a new fuel pump now, but will still check the pressure first, if its ok then I'm all out of ideas with this truck. before it took a crap I did notice the fuel pump was loud and it sounded like the gas tank was empty almost. I had 3/4 of a tank though. Anyway it is probably due. Lastly, you guys were talking about a certain brand of pump to get, is there a reason that I should listen to this or is it just a rumor? The reason I'm asking is car parts are like sneakers you pay for the name in my opinion sometimes...thanks for all your help ill update my post when and if I get the truck running again.