Bought a Broken Down 2002 reg cab Short Bed 4.8 CAN USE HELP! WONT START

[ChevyTruckGuy]

Here is info about this truck http://67-72chevytrucks.com/vboard/s...d.php?t=618250
Now 6 months later......
I bought my friends 2002 silverado after it broke down at the job site. Hes original owner, I have been around this truck its entire life. He gave up on fixing it & accepted my $1000 offer. Its has no major dents, some scratches, interior okay. Rust free, not a bed truck, id like to keep it & make it a regular driver, I bought it & registered it last week. Had it towed home.

Now the truck has 340,000 freeway miles, no big deal for me. Its a 4.8 v8.

It ran perfect until he got to its last destination. It cranks but doesn't start. He replaced the crank censor, added new plugs & wires & replaced another censor but I dont remember which one. Well I got it new & when I spray starting fluid in the throttle body it fires for a few seconds, so I think its getting spark. I went ahead & replaced the fuel pump thinking that was the problem, 4 hours & 300 dollars later it is the same problem. Still no start. I replaced fuel filter & fuel pressure regulator & still no start, another 75 bucks. Funny think is the fuel gauge on the dash reads an empty fuel tank when its 3/4 full. Dash is also saying low fuel. I hooked up a code reader to the truck & its sending out a error message. Now doing a google search im finding folks are having a problem with the theft part of the truck, as if the truck thinks its been stolen. Also im thinking its the computer it self maybe. The pump thats in the tank is very quiet unlike my other chevy trucks. My brother is helping me fix the rig & WERE STUMPED. The relays seem okay because the truck has a few of the same & I swaped them around a bit & still nothing. I added a new battery just in case but didnt work... Maybe a bad ground? Can we wire the fuel pump direct to the battery & not damage it? My friend said he hooked up a pressure gauge to the fuel rail & it read it has enough lbs but I didnt confirm this for my self, just assumed it was the pump like my other trucks. I cant confirm it has spark, I put spark plug in wire & grounded it out & didnt notice any spark

Thats it for now, I can only work on it when time allows, once a month, THANKS for any advice & ill get pics soon.....

[ChevyTruckGuy]

So I tried this method https://www.youtube.com/watch?v=weidkoI7clE

It fires but doesn't sound as good as the motor here in the video does.

Motor defiantly turns over but sounds bad so I think that confirms spark?

Here are a few pics of the truck.

[ChevyTruckGuy]

Looks like my apple computer automatically changes my spelling, I need to proof read my messages. censor is really sensor, haha

my buddy replaced the cam sensor as well.

The motor sounds like it diesels when it fires, maybe coils?

augggghhhhhhhhh

[jjzepplin]

Compression check is first. If good then you have something! If it is good then try this. I don't know if this will work but it worked on my 2000 Toyota. I tried an old timing light on the small wires going to my coils. It went off like crazy on three of four coils so I thought one was bad. RIGHT! Now it does not flash quite the same but it says to me there is activity. Old school but fixed my car. Now if there is coil activity there needs to be gas. You can try some carb cleaner spray down the throat of the offender and pray for action. Again "old school" but should work. Unless someone is telling less than the truth- It can't be something huge that is wrong.

[vanaman]

have you checked to see if you have fuel pressure?

[67ChevyRedneck]

Buy a fuel pressure gauge. You said a friend had one. Just get one, they're cheap. I think the pressure is supposed to be around 50-55psi. There should be pressure before you start the truck (check ball in fuel pump). Do you hear the pump prime when you turn the key? When I changed my fuel pump my truck wouldn't start... I forgot to reconnect the ground wire at the fuel filler neck (didn't make any noise when I turned the key on).

Also check the fuel pressure regulator (circle thing on DS fuel rail with vacuum line going to it.) Try to start truck. Pull the vacuum line. If there is any fuel at all in vacuum line, or comes dripping out of regulator, it's bad.

If it ran fine, then nothing at all, I don't see it being a coil pack/spark issue because the chance of several, or all 8, going is near impossible, and the motor will start/run with misfiring coil packs. It could still be a computer or fuse issue though.

[truckdude239]

if you srpayed start fuild in it and it kind of started you have a fuel problem. check your grounds on the back of the heads and near the battery i had my ls swap sound like that, would kind of start on start fuild but not run, i ran a ground wire to the computer case and that sloved my problem