2000 454 vortec constant problems what to do?

[someotherguy]

Passlock kicking in is a very distinct and consistent behavior - it will allow the engine to start for literally just a moment, then shuts off fuel to it, so it stalls. The security light on the dash will be flashing. Remember, it WILL let the engine start, just immediately kills it after it starts. If this isn't what it's doing (and it didn't sound like it) then you can cross Passlock troubles off your list.

Richard

 

[65nightmare]

Passlock kicking in is a very distinct and consistent behavior - it will allow the engine to start for literally just a moment, then shuts off fuel to it, so it stalls. The security light on the dash will be flashing. Remember, it WILL let the engine start, just immediately kills it after it starts. If this isn't what it's doing (and it didn't sound like it) then you can cross Passlock troubles off your list.

Richard

That is what it was doing when it ran. Every day no matter what i always had to start it twice. Then some days the key would kick the fuel pump on and not the starter so i would crawl underneath jump the starter it would run and shut of so i would go try the key and if the key worked it would fire up and stay running sometimes in would start and shut off 3-4 times before it stayed running.

 

[65nightmare]

But now it just cranks and dont start and the alternator is good i also put a new battery in it today.

 

[65nightmare]

Ok so i am getting weak spark at the coil and no spark at the plug but it does flicker a test light at the plug just not enough to see a spark im assuming. Could this be my icm?

 

[Mangonesailor]

Ok so i am getting weak spark at the coil and no spark at the plug but it does flicker a test light at the plug just not enough to see a spark im assuming. Could this be my icm?

Could be the ICM. Take it out and have advance/autozone/etc test it for you.

Definitely put a FPR in there or else that'll be the next thing to screw you over.

 

[65nightmare]

Could be the ICM. Take it out and have advance/autozone/etc test it for you.

Definitely put a FPR in there or else that'll be the next thing to screw you over.

After its running again I plan on doing injectors, fpr, plugs, wires, and probably a fuel pump I've ran it to long without and like now I have no clue where to start when it doesn't run at all.

 

[dannymcd]

I've had a 97 with the 7400 for about a year and a half, I had random stalls while driving and once while pulling my 6k# boat. check the main positive and ground leads from the battery, once i improved those the flickering and the weird electrical gremlins stopped. It could be a number of things, since your fuel pressure goes to 40, the quick drop to 0 probably indicates a leaky injector or bad FPR, I had a very long crank issue but the first start of the day was always quick since letting the truck sit overnight would allow the dumped fuel to vapor off. Still this is a far cry from not starting at all. I usually start with the electrical stuff first since it ultimately controls everything and after all it is a GM.

 

[65nightmare]

Ok so I had the icm tested and it was bad so I got a new one, changed it still no start but the only code I am getting now is
ignition control circuit high voltage?

 

[65nightmare]

Last update I put a new coil on and found a bent pin in the new icm so I straightened the pin and it fired right up and runs just as before (not great but not bad) so thanks to all for the info!

 

[88GMCtruck]

Glad you got it back to running - at least where you were before. Sounds like you are ready for a full fuel tune up to me.