When i try to start my 97 silverado it takes like 4 or 5 times of cranking it to get it started.. i've already changed the distributor cap and change the spark plug lines.. what else do you suggest

What fault codes do you have?

Don't know if this will help you or not. But we found out with our 97 Silverado, that almost everything electrical went through the ignition switch. You might investigate an ignition problem.

Did it act like it wanted to start when you did that? You say cps but truthfully that don\'t tell me if its crank or cam? It should have a real distributor and you should check fire from there. Look at and check cap, rotor, and wires and make sure they are on correct If you still have no fire then replace ign coil.... Now.. if it was tring to crank when you sprayed it then listen on how it cranks. If it turns over slow,fast or if it sounds retarded. If any of those occur then check timing and all its componets. Make sure the fire you checking is good spark.. blue or red or both just as long as its fire. If you\'ve replaced the coil and still no fire then prolly gone be a timing chain broken but most of the time engine will turn over a lot faster in this factor. If you\'ve check chain and its good, then a broken cam or crankshaft is obvious. Now... you can dig deep into the whole checking voltage and computer if you like... but my personal experience is this problem has never been PCM or ECM

Sounds like timming to me?

check the firing order

Did you check the timing belt to see if it broke? It ha a 2.5 and it has belt. Remove timing cover at the front of the engine and have someone crank it while you watch the cam to see if it turns. If it doesn't turn, replace the belt.

If you changed the timing belt already, I would turn the crank back to the marks (TDC) then pop off your distributer cap look at the rotor it should be pointing at the spark wire to the No 1 cylinder, note : if it slipped off timing you could of damaged a valve...
to know if your cam is at tdc (you would have to pop off the valve cover) as you turn watch the valves there is one with a chamber to the exhaust manifold(header) that is the wrong one to watch....the one next to it should be lifting up or closing as you turn the crank to TDC (sealing the chamber) at the same time the distributor rotor should be pointing to that point under the cap...the cap is usually have small number underneath...

sounds like you have the plug wires on the cap mixed up. reccomend recheck the order and make sure they are in the right order

Possibly the crank sensor.

crank shaft sen. is easy enough to change.its mounted near timing chain cover,cam sen.is somewhat harder,its in the distributor,id doubt that both are defect