ss.slp.ls1

iTrader: (36)

I have a '94 Trans Am. I recently swapped in a LS1/T56. Engine, wire harness, and PCM came out of a 30k mile, good-running car. VATS has been deleted. I wired up everything I can think of, not my first LS1 swap, but the car won't fire...cranks strong, good fuel pressure, but no fire. I checked everything obvious I can think of, any other ideas?

Checked PCM
-checked Blue 1, Blue 40, Red 1, Red 40 for ground. Good
-checked Blue 20 & Blue 57 for bat +. Good
-checked Blue 19 for ign +. Good
-code reader communicates with PCM
-fuel pump primes

Checked sensors connectors
-checked both sets of coil packs for ign +. Good
-checked both sets of coil packs for ground. Good
-checked both banks of inj's for ign +. Good
-checked MAF and o2's for ign +. Good
-checked MAF and o2's for ground. Good
-cam sensor is plugged in
-crank sensor is plugged in

Checked grounds
-three grounds on the back of the driver side cylinder head are tight.
-battery ground to chassis is tight.
-battery ground to engine block is tight.
-engine block ground to chassis is tight.

BlueZee28

iTrader: (7)

Try replacing the crank sensor, a bad crank sensor will allow you to crank until the end of time but no start. You'll also have good fuel pressure, just no spark. I know this from personal experience, I was very frustrated when my swap wouldn't fire up on the first try. I got a new crank sensor and it started instantly.

ss.slp.ls1

iTrader: (36)

I thought about that but the engine was recently pulled from a low miles, well-running car. I'm assuming the sensor is still good.

Can you see the signals from the crank and cam sensor using a scanner like a Tech II?

ss.slp.ls1

iTrader: (36)

Found something while searching on Tech to test tonight. I originally tested for all ign + with the KOEO. I need to verify the same points while cranking as well. Hopefully that's it.

99MUSTANG5.3L

Did you check both grounds at the coils? I had same issue, checked the coils individually for grounds, and it turned out that the black ground wire was not connected in the harness. I hooked them to ground and it fired instantly.

Rick Speed

iTrader: (55)

I'm not getting a good ground either on my 94 TA LS1/A4 swap and I temperarily grounded the pcm case and its working till i figure it out for good

ss.slp.ls1

iTrader: (36)

Turns out what I thought was a constant ign wire didn't have power during cranking. Swapped wires and it fires right up. Sounds sweet too. Thanks for the responses.

LS1MCSS

iTrader: (18)

That's a common problem with swaps. I see it on here a lot.