I have a 1990 TPI 5.7 that was starting fine, and now will not hit a lick...
I have done the following:
checked for spark on both sides-good
checked injectors on both sides with a light--good
fuel pressure is at 45psi with ingition on
confirmed timing at (#1 at TDC and distributor is ok) was timed 6 deg, but wanted to confirm
checked plugs by pulling -good spark
changed ecm (122-7730) just in case
Also checked TPS voltage ~0.52 volts
took ignition module in and had it checked---it's good
no codes but 12--good
replaced the dizzy pick up coil
held throttle wide open, clear flood mode--didn't start.

went thru swappers guide and all checks out
What am I missing, why won't it fire, i mean i have spark , fuel??
I do smell fuel....

I am to the point were it has to be a electrical issue somewhere??? any direction, it went from running to not firing?????

 

I'm going to guess there's some history here that we haven't been told about.

What happened when you did the most obvious thing, which of course was when you just put in NEW spark plugs?

 

it was running and started on first crank every time. It was having idle in drive problems, contacted a guy and he said the fuel pressure was too high, it was around 50psi. So, when adjusting the fuel pressure (I have an adjustable regulator and gauge) I was told to disconnect the vacum line for a more accurate reading. I know I plugged the line coming from the maniflod but cannot remember if I plugged the line to the regulator. It almost fired once then nthing since. I kinda thought it could be the fuel pressure regulator, but it is holding pressure and plugs are getting fuel.