ok so here is my problem. everything is completely wired up....i think. i go to crank it over just to see if the start will turn the motor over. and nothing. no click. nothing. i then checked to see if the purple wire to the starter selonid was getting power when cranking. and nothing. i am at wits end i have no idea what it could be. it might be something so simple but i am so frustrated and tired of it that i probably over looked it. i will list some random things and see if it has anything to do with this and it might spark some of ideas from you guys.

when i put the ls1 in a took apart the factory 305tbi harness and removed all sensors and left only a/c circuit. the red fusable links to the junction block and TO THE STARTER.(am i suppost to keep those?) i removed the fan relay and wiring but left the fuel pump relay and wiring. and once the motor was installed i hooked up the fusable links to the starter and the ones to the junction block. also i put what was left of the grounds on the back of the old 305 cylinder heads to the ls1 cylinder heads.

the new harness had 8 wires to plug in to make everything work. only 2 were needed to make the motor actually run. 12v switched i plugged into the acc hole on the fuse block under the dash. and the other wire was a cranking signal which i connected to the purple wire that went to the starter on the 305 setup.

i have no idea what to check for or anything. at this point i am at a dead end of diag. if you have any suggestions please suggest. no matter what i will check anything. vatts? power at the old ecm? ground? idk im confused and frustrated.

any and all help would be greatly appreciated.

ryan

 

Well all you need to turn the starter over is the main power wire that runs directily from the batery to the starter and the signal wire that sends 12v to the sylenoid (cant spell srry) when the key is in the start position.

 

I hope your not trying to use your old ecm with that ls1 or you will have alot more problems besides starting the car it has several sensors that don't match your 305 tbi motor. Also you will need to get a wiring harness for that particular engine. Question are you running injection or carb because if you left the injection unit from the ls1 on there you will definitely require a new wire harness just my

 

i have a LS1 PCM and a LS1 standalone harness. im not using my 305 ecm. it will be left in the car but i am not using it.

 

double check you connections. sounds like youre A) missing a ground or B) somethings not connected right

 

well i got it started. but it only stays running for 5seconds then shuts off. but i already deleted all of the vats off the pcm. so i think something is taking away the power from the pcm. not sure what. any ideas?

 

I've seen it time and time again. 99% of the time if it runs and shuts off after 5 seconds VATS is still enabled. Reguardless of whether you think you did or not.

Kevin D.

 

ok so i have efi live. there is a theft tab. in the window it says this. vats power/no/serial. i clicked NO. and on the column lock it was already clicked no. what else is there to vats when reprograming?

 

Not sure, I'm just saying with everything I've read I would start there.

Kevin D.

 

I'd pick up a VATS bypass on ebay... thats the only sure way to know VATS isn't an issue. They are like 5 bucks and 3 wires to hook up.

Is your old 305's ECM still getting power and running? If so I'd unplug that just to make sure its not screwing with anything.