Green87

87 Camaro 2.8 Multi-port Fl I’m doing a LS swap in LS 53 4L 60 E transmission standalone harness I am getting power at the coil packs Injectors but cranking the car over and testing with a test light the test like a super damnmon the coil packs why cranking I’m losing voltage somewhere car cranks over but don’t start first LS swap ever need a little bit help out there please and thank you and I’m trying to figure out if this car came with VATS System or not because I do not have a relay on the side of the kick panel on the driver side

camarorsssss

iTrader: (2)

You have fuel? Spark?

Green87

I have fuel but no spark cranking car over while testing spark with A spark plug tester No spark

ironwill

'87s didn't have VATS.

What are you using as a PCM?

Green87

i’m using the computer that came with my junkyard harness but I have a brand new standalone harness to go with it

Green87

And it’s blue and red one

ShiftyCapone

iTrader: (7)

Is your ECM properly grounded? You getting the right power to the ECM?

ironwill

If it's the stock GM computer, and you have the diagnostic port to go with the harness, connect a scan tool and see what trouble codes it has. If you can't do that, since yours is a 'custom' installation, you'll have to trouble-shoot it on your own.

Green87

I have a chassis ground from the harness and a ground from the back of the head from the harness to and two Red wires for power to The starter and what do you mean by ECM properly grounded does computer need to be grounded to some that’s what you’re saying because I have those three things Grounded that came with the harness

Green87

And how do I troubleshoot it on my own

ShiftyCapone

iTrader: (7)

Is the ECM you are using right out of a truck? If it wasn't flashed to get rid of vats it likely wont fire.

Green87

it came out of a 2003 Tahoe and I sent it to the place I got my harness from and they were supposed to delete that but they probably didn’t I don’t know how much does it cost to do that

Bishopts

I ran into a similar problem when I did an LS swap on my bosses truck, I had one of the pink wires (which are normally key hot) wired to the ignition switch in a way that the power went away in start but was there in run.

Green87

Did you ever figure out what the problem was and how to fix it

ironwill

I don't know what to tell you that wouldn't involve writing a book.

Start with the basics. Fuel, spark, air intake and compression---all at the right time---is what's required for an engine to run properly.

Green87

What’s up bro I got my computer Tuned it still won’t start for some reason cranks over

Bishopts

It's been said already. Start with the basics. Air, fuel, spark.

spark would be easy to check with an old plug and a friend. Pull one of the plug wires off of the plug in the head and put the old plug into it. Ground it with vise grips or maybe some jumper cables , in a way that you can see the electrode and watch it as your friend tries to start it. You should see a very small spark where it's jumping the gap.
Fuel check fuel pressure first, a fuel gauge is recommended. They have a service port in the rail usually, but if you need to you can pull the feed line off and aim it into a container and spin the engine over. It won't tell you if you have pressure but if nothing comes out then you know the fuel pump isn't doing its thing. If you determine you have pressure look for injector pulse with a noid light or fold the wires back on a 3056 bulb and put the wires into the injector plug in a way that it completes the circuit so that you can spin the engine over and look for a injector pulse.
for Air usually make sure you didn't leave a rag or block off plate in the intake and then do a compression test for at least one cylinder on each head.
For quick results and to move this whole process forward try starting fluid first. If it tries to run on starting fluid or it does run on it then something in the fuel area is the problem.