Jay Johnson

iTrader: (16)

I've got everything together on the motor test
stand but NO SPARK. I have a known-good motor on
it and everything is plugged in(at least I think
so).

Fuel pump comes on, starter comes on, injectors
come on, but no spark, and a-tap can't talk to the
pcm. So, I figure there is a problem with the pcm
or the wiring harness setup.

I put autotap on but it can't communicate with the
pcm.

I took apart a 99 SS and got the complete harness,
steering column, bcm, ignition key. I didn't get
the pcm, but I found a 99-2000 pcm and got it
burned in by a friend at a dealership with the
same vin# of the original car.

It shouldn't be the VATS, I have the original key
and original bcm, plus that shouldn't keep me from
communicating with a-tap to the pcm.

I tested the ground wires in from the pcm, and
those worked. I tested a couple of hot wires from
the pcm and those worked. I had a 2002 pcm at the
workshop and I put that in, but got the same
results. A-tap couldn't communicate with the pcm
and the motor wasn't sparking.

Anyone run into a problem communicating with the
pcm for their conversions?


Jay Johnson
jayjohnson@rocketmail.com

Speartech

iTrader: (14)

Spark is the easy one to get, since it's unaffected by VATS. You have apparently missed one of your power up wires or something.

Is the crankshaft sensor plugged in behind the starter solenoid?

If your fuel pump is wired correctly, it should run for 2 seconds when you turn the key on. If the PCM is "seeing" the engine turn during cranking, then you should hear the fuel pump run for another 2 seconds when you quit cranking. That indicates that the crankshaft sensor signal is making it to the PCM. If the PCM is "seeing" rotation and the coil packs are powered up properly, you should have plenty of spark.

Do you have 12 volts on pin 16 of the ALDL?

Jay Johnson

iTrader: (16)

The crank sensor behind the starter is plugged in.

I checked the power and grounds in the aldl, those
came out good.

The fuel pump does it's usual 2 second spin, but
nothing nothing more.

So, I suppose that the pcm isn't seeing the crank turn.

Plus, Autotap can't communicate to the pcm as well.
I think that's the problem that's in the way of
starting this rig up. I checked a number of wires
on the blue and red pcm connectors, all of the
grounds were good and I checked a couple of the
orange hot wires to be good.
The power leads seem good. So, there's no comm to
the pcm, but it's getting good power leads.
That seems to indicate that the harness is okay
(to my knowledge), maybe it's the pcm?
I tried the newly burned pcm and a stock 2002 pcm.
BOth gave the same results along with the same
autotap indications(can't connect, it actually
errors out where it reads fine on my race car).

thanks for the ideas, keep them coming <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />


Jay Johnson

<small>[ March 30, 2003, 10:49 PM: Message edited by: Jay Johnson ]</small>

Jay Johnson

iTrader: (16)

Any more ideas?

I'll try to put in my known-good 99 pcm from my
race car into the harness and see if I can get
a-tap or ls1-edit communications.


Jay Johnson
jayjohnson@rocketmail.com

jeromio

There's an easy mistake to make (I know, I made it) with the harness. There are 2 DkGrn wires on the same connector (101 I think?). Same color, same connector. One goes to the FPR, one goes to the InstPanl and the data plug. Oddly, make that insanely, the motor will still run with these wires crossed. But of course ATAP will not connect, and the motor will run like ***.

I dunno about no spark. I haven't had that problem. I have lost fuel pump power a couple of times when wires came loose (or else I disconnected them and forgot to reconnect).

Jay Johnson

iTrader: (16)

The harness was intact, I didn't have to setup the
wiring.

So, I do not think a crossed wire would be a part
of the issue.


Jay Johnson