Will not start VATS?

[taker73044]

I have a 1995firebird with a 3.4l V6. I just changed out the engine. The Old engine had a cracked cylinder wall. the new engine came with harness and computer. The car ran before the swap. After the swap it will not start. It has spark at the plugs and the fuel pump is working with 42lbs of steady pressure. The injectors have power but they are not pulsing. I had the ICM tested it is good and I swapped the computers with no result. now for the odd thing there is no security light at all coming on I check the bulb its good. And I have check the engine harness over and over to make sure I didn't miss a connection. im am stumped..

[caffeine]

Did you try using the original PCM?

[caffeine]

Also, if it's a VATS issue the engine will usually start and run for a second or two an then the injectors will be disabled

[taker73044]

Yes I have tried the original PCM with the same result. when I turn on the key the security light don't come on at all and I thought it was suppose to for a few sec's then go off. But it is doing nothing. I also understand if it was vats the fuel pump should be dead along with the starter.

[robertisaar]

depending on how you operate the key, will determine how the VATS system reacts.... if you roll the key forward and wait for the pump to quit running before cranking, then you may get a never-start. if you immediately run the key from off to crank with no waiting and it fires, then it can do the start, run for a second, then stall crap.

the VATS module CAN allow starter operation, yet no injectors.... if the signal from the module isn't making it to the PCM(bad wire, bad module, bad PCM), then the starter will be allowed, but the injectors won't fire.

fuel pump isn't related.

after the key rolls forward to RUN, security light is supposed to come on for 5 seconds, then go off, that is normal operation. if it stays on longer than that, the module isn't liking the key. the fact that it never comes on is a problem.

here are some troubleshooting steps, but for some reason, there is no "light off, cranks but not run" chart(perhaps the perfect storm of failure?), so i grabbed the closest thing to it.

http://imgur.com/3ASIVHL,SQMiKgK

[caffeine]

Maybe disable the VATS module altogether? Should just require a quick flash of the PCM and I'm not sure what else but on my '89 I just had to ground a wire under the dash to disable VATS completely

[robertisaar]

to completely remove both parts of the system; bypass the starter disable relay and either generate the 50Hz "allow injectors" signal using other hardware or remove the option from the calibration.

[taker73044]

Ok well the bad the engine turns out to be shot got it to start and it started knocking then locked up. so back to the drawing board and note to never by a engine off craigslist again. Now on to what the problem was I had the bright idea of testing the injectors off the old engine to see if they would pulse and they did oddly lol. so I swapped the whole setup and it started for the brief period till it craped out. Oh also the vats system was trashed not sure how it even started. it did not have a bypass of any type and the wires to the ignition switch were cut. but the end result was switching the injectors.

[1988GTU]

you mention craigslist. where bout are u located?

[taker73044]

Harrah, Oklahoma