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Ls1 Wont start Help Pleaseeeeeeeeee


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ok so i finally got everything to the stage where i believe motor should start but it wont please help

 

basic what i have 99 ls1 manual from gto (or as we know it here commodore ) std wiring loom modified to suit computer had securities (vats) switched off and tuned mafless have sent computer back and had it checked that securities turned off have tried with maf plugged in and out running walbro internal fuel pump with external adjustable aeromotive fuel reg 02 sensors connected but hanging in mid air no exhaust from headers down air temp sensor connected evap is not connedted from outlet but is connected to mainifold

 

What i know of situation plugs fire, engine cranks over, fuel pump fires up, have fuel pressure to injectors pressure guage in line, have power to injectors, power to computer pins 19,20,57 earths to 1 and 40 on computer,

 

my guess is injectors are not firing which is why i got computer checked for securities turned off correctly but wasnt that

 

computer guy suggests earths would cuase this problem says there should be 4 on engine but i can only find 2 one on front right hand side head black and red wire other one at rear of left head

 

can anyone tell me where other earths are or any other suggestions take any ideas been bashing my head on this for 3 weeks now ready to burn the lot

 

please help thanks Mick

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To confirm dead injectors, find a "noid light". I don't know what they're called over there, but that's the official term in the States. It's a bulb that fits into the injector plug, and will blink with voltage. They are available for many different injectors, be sure to get the right style. They're an invaluable "go/no go" tool.

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Something is wrong with your injector circuit. Event if you didn't disable the VATs and everything hooked up correctly you should be able to start it for a few seconds. Turn the key to RUN and check for 12V to the pink wires on all the injectors. The PCM sends ground signals out to trigger the injectors. GL. PS. the injectors don't die all at the same time

 

The power feed for the injectors is at connector C100 pin A - Pink wire.

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have checked injector power at injectors power is there both in run and start postion

I am assuming injectors arent pulsing as im getting no fuel in cylinders when i check plugs there dry no evidence of fuel

 

thanks for your ideas

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Your problem seems like a wiring issues and not the PCM. It's not the crank sensor because you have sparks. Your grounds for the PCM, are you using pin 1 and 40 from both connectors? You need to use pin 1 and 40 from both connectors. If you didn't cut open the original harness all the ground wires for the PCM should be spliced in together already at the Inline Harness connectors. It's not the VATs either. The next question is how do you run your fuel system? Someone on here ran his fuel system incorrectly awhile back and couldn't get his car started. GL.

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have checked that pins 1 and 40 in both harnesses are connected to earth didnt splice loom just connected needed wires and removed any unused plugs

VinZXT can u confirm if theres more than 2 earth points on engine computer person told me there where 4 but i can only locate 2

 

as for fuel i did read post on here about correct fuel lines though the gto fuel rail only has single fuel line input (no return line off fuel rails)

have placed walbro pump in tank ,pumping to aeromotive adjustable fuel regulator with main line running to injector rail and return line from regulator running back to tank this is mounted at tank as per gto tank install

have fuel pressure guage in line showing 58 psi at manifold when ignition is turned on and during cranking pulled fuel line off and check for flow pumps fuel fine

 

thanks mick

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Pin 1 and 40 on both the red and blue connectors are grounds. A total of 4 grounds. Pins are numbered on each connector. You need to remove the plastic cover on the connectors to see the numbers on the metal part of the connectors.

 

Hope that helps.

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have checked injector power at injectors power is there both in run and start postion

I am assuming injectors arent pulsing as im getting no fuel in cylinders when i check plugs there dry no evidence of fuel

 

thanks for your ideas

 

It has to be something simple that you've missed. Did you check the powers to your PCM during both RUN and CRANK? Disconnect the Blue connector and check for battery voltage at pin 20. Turn the key to run and crank and check for 12V at pin 19.

 

PS. Clive had the same symptoms/problem on his LS1 swap. He found out later that I screwed up on the wiring for the Ignition input to the PCM. It has power only in the RUN position but not during cranking and that was the problem that the car didn't start. GL.

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waiting for computer to come back from tuner thanks for all your ideas have purchased noid light today to check injectors and will check all connections plus power to pins tomorrow have also bought spare computer which has arrived before mine orginal came back but need to turn off securities before i use that one

 

dont have codes to check how do u check codes is that through obdii to usb converter so u can read codes as i dont have one

 

im working away at the moment so i only get weekends to try ideas really annoyed computer isnt back to try ideas suggested here

 

mick

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Mick,

If you don't have a scan tool to check codes, drop by autozone and rent their scan tool. I take advantage of their rental tools all the time. Get the code reader, hook it up to your OBDII port (if you have one) and it will tell you if you have any problem codes.

Your still not getting fuel to the cylinders, right?

 

Good luck,

John

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yipeeeeeeeeeeeeeeeeeeeeeee it finally runs

thanks for the help guys finally got it going and it was nothing youd expect got computer back plugged it in with noid light yep one injector firing thought i wanted to be sure so i pulled injectors out and hooked them up upside down on top of the motor only the left bank was shooting fuel out so i pulled out spare manifold i bought off ebay (those bargins always pay off just go to wait ) tried injectors from spare manifold the same way and all 8 fired fuel so fitted that set injectors and hit start away it went man it sounds great straight out of headers

 

now i can start finishing things off putting guards back on and cooling fans plus tacho and speedo connections but

 

thanks heaps for the help still smiling like and idiot

 

mick

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