devic

hey guys hoping some one can help me out with this issue, ive been searching for weeks and replaced near everything on my car with no luck,

well the problem im having is the coils 4,5,7,8 are firing but they are all getting 12 volt constant and ground when the key is turned to the on position, also getting pcm ground and when cranking the car im am getting trigger voltage.

i have tried to switch the left bank with the right bank and i have tried swapping individual coils, yet the same cylinders fire

also i have replace my fuel filter fuel pump and in tank regulator and used compressed air threw the lines (disconnected at the rail and filter)
* i know 1 injector o-ring is leaking on the fuel rail side, but before i replaced the regulator it was @ 40 psi and now it is barley @ 20 psi
- racetronix 255lph
- and a have the hot wire kit but have not installed it yet
- the regulator came with the little black housing that connects to the assembly but i could not get it off so i just switched out the regulator its self

the car does try and crank but does not get to full idle speed kinda like its lopping then bogs and dies after about 2-6 seconds (this is contestant on both fuel pressure's)

the car is showing the check engine light how ever i have no access to a scanner of any worth & the "red" check gauges light is also on

parts replaced:

intake gaskets
torque converter
starter / solenoid
throttle body
throttle body sensors
egr & air delete
fuel filter
racetronix fuel pump 255lph (i have the hot wire kit but have not put it in yet)
oil & transmission fluid
transmission filter
pcv oil catch can
new battery

modified parts:

slp lid
02 simulators
cat gutted
msd wires "i made using the factory connectors and boots"
3" magnaflow cat back
all free mods

a little back history on my car:

had a t-tech done on my transmission after 60,000 miles, not knowing to replace the front and rear seal on the transmission at the same time, ended up blowing the seals out a couple days after, pulled the transmission couldn't get the quick disconnect lines off so i asked my friend to get them of will he just cut them instead, put the seals back in put the transmission back in, bout a month later it started to sound like it was knocking, so i pulled the motor in doing so found out it was the torque converter bolts had not been tighten down enough

car sat down for awhile. finally i put it back together, the car didn't want to stay running at first then i held the rpms up for a few min. straight and it finally started to stay running, went for a drive got on it kinda hard, then it started to try and die when ever idling, so i headed back to my house almost there heard a sound that was almost like a bolt flying around in my bell housing, then the car just powered down all the lights went out wouldn't crank back up or do anything, got the car home found out the starter had broke off the car, ended up pulling the transmission to inspect the flex plate for damage, then the car sat for 3 years until now, and is have the above listed problems

mrmint69

You should try the old regulator and see if it returns to the right pressure. Fix the leaking O ring and make sure your alternator and battery are in good working order. Fix the easy ones first and get that code read some how.

devic

the battery is brand new and the alternator will do nothing seeing how the car is only running for 6 seconds the car is still being powered off of the battery

"i need held figuring out the major issue more so than the simple fixs"

devic

so far ive been on ls1.com / chevytalk.com/ ls1tech.com and some other site i cant think of them name right not, ive personally tlke to GM master mechanics in person seeing how my boss's husband is 1, ive call performance shops that only deal in ls1 cars

why can no 1 out there figure out this problem ?

ive been searching google and the above listed web sites for weeks now and i find tons of people with this same problem but no one figures it out or helps them, the best info ive gotten so far was the working operation of the crank sensor to coil pack of a hemi, couldnt even find anything as close to as detailed as that was about a ls1

bobdec

Low voltage (below 8-10 volts) will cause PCM failures and erratic running, 20 lbs of pressure could be why it stalling after 6 seconds. As said in post #2 , go after the obvious fixed first, they are not minor problems and can be causing a host of other symptoms.

devic

yeah the only other problem im having is the low psi but i have changed everything but that 1 leaking o ring and the only problem im getting from tat is leak down in pressure that take about over night for it to even leak down

devic

so based on what ur saying low voltage to the pcm hmm bad pcm ground ?