Conversions & Hybrids - grrrrrrrrrrrrr...ls1 wont start this time...

when i had my motor in for mock up...it started fine after i sorted out the vats bypass module...

this time i can't get it started...

i put ignition +12v to all the pink...checked and verified...
i put constant +12v to orange....checked and verified to blue connector pin 20 & 57...
i grounded blk/wht wire on c101 plug...checked and verified ground back to blue connector...
checked 12v to injectors...
checked 12v to coil pack...

i get a healthy crank from starter....but no fire...
will invest in a dummy light probe tomorrow...

got fuel cuz i pumped out the old fuel to put in new fuel via the fuel pump through vette fuel filter...i can also hear fuel cycling...i can feel pressure via the hose to fuel rail...

grounded 3 ground wire to back of head from wire harness...grounded negative post to chassis and front of head on passenger side...power lead to fuse box for pcm...power lead to body harness...power to starter....power to alternator....

there is fresh oil...there is fresh atf fluid...there is fresh coolant...

i don't think it's the vats bypass module...being that the motor wont even fire...i wanted to say it's the power/ground to pcm but i've already verified it to the pin from end to end and with power/ground applied...

i am now stomped...what else can cause motor to not fire???

Have you pulled any plugs to see if their wet w/ fuel?

Hate to ask, but I did it myself, are the main plugs to the coils plugged in? Overlooking simple things gets me every time.

Have you pulled any plugs to see if their wet w/ fuel?

Hate to ask, but I did it myself, are the main plugs to the coils plugged in? Overlooking simple things gets me every time.

its dark out...so i haven't gotten to that point yet...i changed out spark plugs with new spark plug wires and they are plugged in...i feel too that it mite be something simple...the big plug plugging into the coil pack harness is plugged in...i had to unplug it to verify power...come to think of it...the plugs for the individual coil packs were plugged in also but i didn't check voltage at the individual coil pack themselves...will do that tomorrow...

Maybe crank and or cam sensor? Are you sure the pcm is getting a constant +12v while cranking? A noid light is worth its weight in gold when it comes to performing these swaps.

Maybe crank and or cam sensor? Are you sure the pcm is getting a constant +12v while cranking? A noid light is worth its weight in gold when it comes to performing these swaps.


pcm is def getting 12 volts constant...cuz it goes str8 to battery...

Maybe crank and or cam sensor? Are you sure the pcm is getting a constant +12v while cranking? A noid light is worth its weight in gold when it comes to performing these swaps.



got me thinking...need to check the ign power while cranking...

problem solved...fooking ignition power dropped during startup...moved the ign lead str8 to battery to remove any doubt...started rite up....i couldn't wait till tomorrow so i took a shop lamp and started working at it...

hopefully if someone has starting problem this thread would help them out...

thanks for the idea!!!!:bang:

Dropping ignition power while cranking is a common problem.

Dropping ignition power while cranking is a common problem.


well the lead tapped into dropped while cranking....forgot which lead i tapped into the first time...but i need to find ign lead that will not drop...just happy that it's something simple...

A noid light is worth its weight in gold when it comes to performing these swaps.

what is a noid light?

a noid light is a test light or you could get the little more expesive probe light ... I have a snap on that I bought back when I used to install alarms and remote starts for a living, that you can plug to the battery or lighter and when you probe a wire. it will tell you if it has power or ground, and also is safe and will keep you from making the air bags deploy when incase you mistakenly probe lets say a "air bag" wire on newer cars...also will keep you from frying a pcm if the wrong wire is probed...