Ill make this short as possible. I just finished building my new engine and got it started. It ran a few times not really wanting to idle but I had not set my initial timing or done any adjustments but it did run. I went to start it the next day and it would not fire it would crank over just fine but not even a cough to start. Ive narrowed it down to my injectors not firing (brand new 64# siemens from blowerworks) I replaced the ignition module that did nothing. By the way I am running a ostrich2 and aldl and tuner pro v5 from moats and have a custom tune also from blowerworks and have checked that the vats has been dissabled. One thing I have noticed is when im cranking the engine over I am not getting a tach reading on the dash or in the tuner pro monotoring. so im thinking the ecu is not getting the signal to fire the injectors. does anyone know which pin and what voltage to check for to see if the signal is getting to the ecm? Here is my engine

gm 4bolt main block .030 over
arp main studs
gm forged crank
eagle 5.7 h beam rods
JE blower pistons 16cc dish
clevite h bearings
tpis ported 113 heads machined for fell pro loc-wire head gaskets
crower 1.6 stainless RR
comp cams valve springs
comp cams cromolly 7.2" pushrods
tpis zz9x cam
tpis mini ram intake
tpis 58mm TB
siemens 64# injectors
fluiddamper balancer
canton 7qt road race pan
melling pump w/high press spring
hooker LT 1.75 headers
dual 3" exhaust no cats
msd 6m
taylor 10.4mm wires
davis unified ignition coil
vortech supercharger from blowerworks
gss342 intank pump w/secondary 255 inline and ractronix wiring kit
ostrich2

 

Your engine won't start because it has no spark. The tachometer gets pulses from the primary of the spark coil, so if the tach isn't working, you aren't getting a spark either. You can check for pulses on your injectors during cranking with a noid light (available at parts stores). The ECM uses reference pulses from the distributor to pulse the injectors. If the pickup coil in the distributor is defective, or the spark module in the distributor is defective, you will get no reference pulses (purple/white wire) to the ECM and therefore no injector pulses and also no tachometer reading.

 

I did check the injectors with a noid light and got no blinks from it and I have checked for spark and there is. I went ahead and replaced the ingnition module inside the distributor thinking it may not be sending the pulse to the ecm. That made no difference. I then disconnected the 4wire plug from the distributor and momentarily applied voltage to the purple/white wire and got no tach reading. I ohmed the wire to ground to see if there was a short but there wasnt. I went ahead and replaced the ecm and that made no difference either. The one thing I have noticed is when the engine is cranking over the security light is flashing. I have vats dissabled in my tune and verified it (im using tunerpro5 and a ostrich2 emulator) any other ideas im at my wits end right now

 

The purple/wh wire should have pulses on it when the distributor is being rotated and the ign sw is in run or crank. The white wire (of the white and pink wire pair) goes to the tachometer and it too has pulses on it when the distributor is rotated. The tach wire is connected across the spark coil primary. It would be best to look at the waveform on these two wires with an oscilloscope, but your VOM (voltmeter, ohmeter, milliammeter) test meter on AC should measure something on these two wires.
Since you get no pulses on the injectors, first check the two injector fuses with an ohmeter. With the ign sw in run, you should have battery voltage on both sides of each injector fuse. See if there are any stored error codes and follow your GM service manual diagnosing error codes.
To get injector pulses, both injector fuses must have 12v on each end of the fuse when cranking/running AND you must have pulses on the purple/wh wire out of the distributor when cranking/running

 

Im leaning towards no pulse from the distributor (purple/white wire) I did check it for continuity to the ecm (which is new) and it was good. also put in a new ignition module. what sort of refrence signal should I see at ckt430 location b5 at the ecm?

 

My 86 FSM says 1.3 volts with engine running. I would expect the same for engine cranking.

 

your engine is saying omg, look at those injectors. i might not as well start until he brings those down to a level at which I can burn what he throws me.
Did he not look at my original 22 pounders?

 

Yes but I have a custom tune from Greg at blowerworks to use the injectors. and the engine ran 4 or 5 times for approx 20 min.

 

Ha figured it out..... She was out of gas!!!!!!!! wierd that both my mechanical under hood and electric pillar mounted fuel psi gauges showed 40psi and would hold press for at least a day..well at least air pressure