MORE lsx wiring questions

[smartass12]

Originally Posted by dec010974

please dont call me when im sleep. that is how i stay energized to be able to work on lsx swap. California, i think is 3 hours behind Miami, Florida. I am mainly free during the evenings. Question, are you using the stock under hood fuse block? if you not using the stock fuse block, i wouldnt worry about that. if you rewiring your harness for stand alone opration, just follow Brendan's instruction. just make sure your lsx starter/solenoid is wired in the normal fashion.

Ill be using the current performance for relays/fuses for the motor and then a painless for the chassis. (if that makes sense). So starter/solenoid wired normal would be 12v to starter from batt and feed from ignition (start) to solenoid correct?

[ls1nova71]

Originally Posted by smartass12

Ill be using the current performance for relays/fuses for the motor and then a painless for the chassis. (if that makes sense). So starter/solenoid wired normal would be 12v to starter from batt and feed from ignition (start) to solenoid correct?

That would be correct.

[smartass12]

Originally Posted by ls1nova71

That would be correct.

thanks

[smartass12]

EPIC FAIL.....tried to start the LS on sunday (yes the pressure was on with all my buddys standing around watching football and heckling me)..At first i had the starter wired through the Current Performance fuse/relay as per their instructions...turn the key..NOTHING...then i rewired the starter the standard way and the starter turned over but was very weak as if i had a dead battery...(battery was at full charge) Any thoughts?

Also, isnt the fuel pump suppose to kick on then the key is turned? During several attempts to turn the key only once did i hear the pump turn on and it ran continuously until it switched the key to the off position. The system is new do i need the purge the lines somehow? Any thoughts?

[smartass12]

And another couple questions....

I dont have the TCC wired up yet per lt1swap.com but im not tring to drive it yet just start it, does that matter?

And when wired correctly should the pedal (DBW) move the throttle body butterfly (for lack of a better term) when pressed while the key is on? Because mine does not..

[ls1nova71]

Originally Posted by smartass12

EPIC FAIL.....tried to start the LS on sunday (yes the pressure was on with all my buddys standing around watching football and heckling me)..At first i had the starter wired through the Current Performance fuse/relay as per their instructions...turn the key..NOTHING...then i rewired the starter the standard way and the starter turned over but was very weak as if i had a dead battery...(battery was at full charge) Any thoughts?

Also, isnt the fuel pump suppose to kick on then the key is turned? During several attempts to turn the key only once did i hear the pump turn on and it ran continuously until it switched the key to the off position. The system is new do i need the purge the lines somehow? Any thoughts?

Are your battery cables good? Connections tight? Have a good ground to the engine block?

Fuel pump should come on when the key is turned on and run for two seconds unless the engine starts, then it should run constantly. You shouldn't need to purge the lines, the injectors will open and let any air out.

TCC doesn't need to be wired up for the engine to start.

Usually the butterfly will work with just the ignition on, but I've seen some where it only works when the engine is running.

[smartass12]

Originally Posted by ls1nova71

Are your battery cables good? Connections tight? Have a good ground to the engine block?

Fuel pump should come on when the key is turned on and run for two seconds unless the engine starts, then it should run constantly. You shouldn't need to purge the lines, the injectors will open and let any air out.

TCC doesn't need to be wired up for the engine to start.

Usually the butterfly will work with just the ignition on, but I've seen some where it only works when the engine is running.

Ground to engine block...GREAT CALL..i dont think i have one..just grounds in harness and on battery. I can just ground block to frame because battery is ground to frame correct?

[ls1nova71]

Originally Posted by smartass12

Ground to engine block...GREAT CALL..i dont think i have one..just grounds in harness and on battery. I can just ground block to frame because battery is ground to frame correct?

You need a ground from the engine to the frame, and you could do it that way, but you'd be better off to hook your negative battery cable directly to the block (preferably as close to the starter as possible) and then run another ground strap to the frame.

[BR3W CITY]

Originally Posted by smartass12

And when wired correctly should the pedal (DBW) move the throttle body butterfly (for lack of a better term) when pressed while the key is on? Because mine does not..

When you go key-on, you should hear the fuel pump relay prime the fuel pump, and you should also hear a *click click* as the throttle blades do a min-max test to make sure that their sensors and servo's match (double checking itself, should something cause them to get out of phase, this would re-cal them).
If you don't hear that, then your DBW isn't wired properly. If you DO hear that, but then lose throttle control at the first input, then you probably have a component mismtach.

[smartass12]

Originally Posted by ls1nova71

You need a ground from the engine to the frame, and you could do it that way, but you'd be better off to hook your negative battery cable directly to the block (preferably as close to the starter as possible) and then run another ground strap to the frame.

Made sure the block was grounded to frame. I do get continuity throuout the whole truck whentesting ground..My battery is in the rear of the truck, Should i run a ground from battery to block?

[smartass12]

Originally Posted by BR3W CITY

When you go key-on, you should hear the fuel pump relay prime the fuel pump, and you should also hear a *click click* as the throttle blades do a min-max test to make sure that their sensors and servo's match (double checking itself, should something cause them to get out of phase, this would re-cal them).
If you don't hear that, then your DBW isn't wired properly. If you DO hear that, but then lose throttle control at the first input, then you probably have a component mismtach.

Great, i dont hear that at all. Time to start checking that. That shouldnt prevent the engine from cranking over like normal right? Possibly wont start but in cranks over like i have a dead battery but thats not the case.

[ls1nova71]

Originally Posted by smartass12

Made sure the block was grounded to frame. I do get continuity throuout the whole truck whentesting ground..My battery is in the rear of the truck, Should i run a ground from battery to block?

The further away you mount the battery the more important it becomes to have good battery cables, both positive and negative. Sure you'll generally get continuity through out the whole vehicle, but it has to be able to handle the amp load the starter draws. You could have a very small wire that's giving you continuity, I once had an engine ground it's self through the metal oil pressure line, definitely not good. You can run your ground to the frame from the battery, but a steel frame isn't as good of a conductor as a heavy gauge copper battery cable. But if you don't have at least a big ground cable from the frame to the engine block, it's not going to start as well as it should, and the hotter the starter gets the harder it will get to start.

[smartass12]

Originally Posted by ls1nova71

The further away you mount the battery the more important it becomes to have good battery cables, both positive and negative. Sure you'll generally get continuity through out the whole vehicle, but it has to be able to handle the amp load the starter draws. You could have a very small wire that's giving you continuity, I once had an engine ground it's self through the metal oil pressure line, definitely not good. You can run your ground to the frame from the battery, but a steel frame isn't as good of a conductor as a heavy gauge copper battery cable. But if you don't have at least a big ground cable from the frame to the engine block, it's not going to start as well as it should, and the hotter the starter gets the harder it will get to start.

Ok..ill grab a monster ground cable today and try that out.

[BR3W CITY]

Strangely, my optima is rear mounted, and I don't run an extra cable from battery to block.
I have heavy gauge cable grounding to the frame, then my big 3 grounded up front.

[smartass12]

So i put a 4 gauge ground strap from the frame to the block and it still didnt change the fact that doesnt want to turn over..trys a little like the battery is almost dead but i know the battery is solid..Could it have anything to do with the engine harness? My thoughts are NO..it should still crank hard just might not start.

[smartass12]

I might be an idiot...please chime in if so..So my battery is located in the rear of my truck...What gauge wire should i run from the battery to the starter? Rather not say what i ran..might be a tad inadequate

[ls1nova71]

The longer the cable length the bigger the diameter should be. With a battery mounted in the rear of the truck I wouldn't go any smaller than 0 gauge. Have you heard this engine run before? Maybe pull the plugs and see if it cranks over fast?

[smartass12]

Originally Posted by ls1nova71

The longer the cable length the bigger the diameter should be. With a battery mounted in the rear of the truck I wouldn't go any smaller than 0 gauge. Have you heard this engine run before? Maybe pull the plugs and see if it cranks over fast?

I have never heard the engine run. I did however pull the heads to inspect things and all seemed well, had good compression with no leak down after valves were lapped. Put on new head gaskets, head bolts, new plugs, new wires...etc..

[Low Elco]

Originally Posted by truckdude239

thats why i paided to have mine done 225 plus 80 for a hd relay/fuse box i only had to hook up 5 wires! and it start on the second turn of the key

Who did yours?

[BR3W CITY]

Originally Posted by smartass12

I might be an idiot...please chime in if so..So my battery is located in the rear of my truck...What gauge wire should i run from the battery to the starter? Rather not say what i ran..might be a tad inadequate

I have a 0/00awg wire from the battert to a power distro terminal underhood, then a 2awg from that to the starter.

[truckdude239]

Originally Posted by Low Elco

Who did yours?

it was 225 for harness 80 for the hd fuse box and 100 to flash the computer


www.lsx-harness.com

[smartass12]

Originally Posted by BR3W CITY

I have a 0/00awg wire from the battert to a power distro terminal underhood, then a 2awg from that to the starter.

Then that is how ill do it.

[smartass12]

OK....so i run a 2 gauge from the battery to the front of my truck. BINGO! One problem solved. The truck now turns over like it should but does not start. Next problem to take on...must be some wire issues. The fuel pump doesnt kick on for that first 2 seconds or any time after for that matter.

[dec010974]

if the fuel pump is not priming the fuel system as it should, check your fuel pump relay to ensure its wired correctly. Also, check the fuel pump signal wire with your test light. I hope your pcm had the vats removed.

[smartass12]

Originally Posted by dec010974

if the fuel pump is not priming the fuel system as it should, check your fuel pump relay to ensure its wired correctly. Also, check the fuel pump signal wire with your test light. I hope your pcm had the vats removed.

I still haven't looked into changing the way the current performance harness is wired like you have suggested..So far I just hooked up the wires as suggested in there instructions...I think I need to call you...am about to just throw my hands up and have bill at BP make me an idiot proof harness