I know,another wont start question. Let me first start by saying,I have no codes,checked battery and cables,i have changed the starter (warrantied),alternator (spare),bypassed vats and soldered and taped ignition switch wires and turned crank by hand and car still wont start.Also i have moved car. I get a rrrrr when i try to start. Radio doesnt come on and i dont seem to hear fuel pump.It all started a couple of weekes ago when a ran out of gas (apparently gas evaporated). I did start to get a tappit sound when first start up but would go away. Does anyone have any ideas? I'd really appriciate them

 

Sure sounds like a battery . These things can fool you. Have you tried a new battery?

 

I would agree with plumbob When you turn the key the fuel pump in the tank will growl some at first.
the Battery and the ground are the usual culprits and the battery should test about 12 if it is new.

 

I failed to mention,i had the battery checked out and it came back good.Could the battery give a false read?

 

Yes, stick a different one in it that you know works and see. Most of the time it is the Ground wire is not grounding make sure you are on bare metal cables should be clean where they attach to the battery this is a side terminal so check inside that area as well.

 

If it's barely trying to crank, that sounds like a battery and/or connection issue. Check your grounds and connections to the starter.

 

I decided to get a new battery,since they dont ladt like they used too and it was under warranty. I put it in and still the same problem. Now,everytime i try to start the left engine fan comes on and stays running till i pull fuse.I'll look around when i get some time and track down ground wires and check them. The car doesnt make any noises when attempt to start exvept for a sound that soumds like the starter. It lasts for a sec.

 

Well then, my theory is that a short in one of the fan relays or wire in the fan circuit is causing the fan to stay on, and this may be a long shot, but the PCM might think the engine has overheated and has gone into "fail safe mode" as it would to prevent engine damage as if where actually overheated.
First I would test and/or just replace the relay(s) since they're pretty cheap. You could probably get away with buying just one since they're both the same and probably only one is bad. Replace one or the other first and see if the problem is still there and if it is, swap them around.
What year and motor and trim package do you have anyway?
These car don't like their VAT's messed with, if the passcode doesn't get passed through and match what's stored in the BCM, PCM, and ignition chip it will disable ignition and/or the fuel pump.

 

Its a 99 z34 3.8. I have switch some of the relays and still same result. About 6 mos ago us when i bypassed the vats. How can i reset pcm? I appriciate ur assitance.

 

I'm as familiar with 5th gens. that use the "Passkey I or II" system as I am with the 6th gen. "Passkey III" system, but here's a link to an old thread with a similar VAT problem. One my posts has a link to the relearn procedure for the "GM Passlock I" system.
Here's a link to that thread:
https://montecarloforum.com/forum/ge...t-start-56198/

Here's a direct link to the procedure:
http://automotiveandcommerciallocksm...ock-1.html?m=1