So I finally installed my harness to the LS1 and now I can't get it to crank. Everything is connected right(At least I think so) like the two orange wires that go to 12V with a 15 amp fuse and I also connected all the pink ones to the ignition wire coming out of the drivers side from my original camaro harness. I put the key forward and its a no go. I check for power on the ignition and the starter wire but no juice is going through them. Now the VATS is disabled so I was wondering if anybody would have any idea of what it could be. I already checked all fuses and they are all good.

 

Is your car a factory manual shift car? If it was an auto, did you jump the wires for the start circuit in the plug that went to the original shifter?

 

First of all thanks for responding. No it was not a maual car it had an automatic and I converted it over to a t-56. Now when you say if I jumped the wire from the original shifter do you mean the wire for the neutral switch? Because I still have the original neutral switch and I just move it into park or neutral and still no go. If your not talking about the nuetral switch then what color is that wire you are talking about?

 

The wires are yellow and purple. They are they heavier wires in the plug to the neutral safety switch that went to the automatic shifter. Check for voltage there and work backwards to the heavy yellow wire at the ignition switch. If that doesn't help, start checking grounds.

 

Who made the harness? What splices have you done?

 

Its the original harness from the donor Camaro. I've connected the following only. It's two orange wires that are connected directly to the battery using an inline fuse and then all the pink wires, which should be the power for the injectors and coils, are connected to the big gauge pink wire coming out of the drivers side. There is also a big purple wire, coming out of the drivers side, that I connected to the starter.

 

What about grounds? Did you connect the black with white stripe wires to good grounds? Is 12 volts getting to the PCM? Do you have any pics? There is at least 1 red wire coming out of the drivers side bulkhead connector that needs to go to the battery to power the car. It sounds like you missed that one. It goes from the battery, then through the bulkhead (C100) and to the ignition switch, headlight switch and fuse box. My car had two of these, but I have seen a couple early thirdgens that only had 1.

 

I connected the red wires from the bulkhead and also verified that the PCM is getting 12 volts. I went back and played around with the ignition switch and the funny thing is that I put the switch in park and now it cranks. I could of sworn I went through that switch but the problem was just that. Now I have a new problem. No spark! Would the VATS cause that? I had VATS removed but I can't tell if it was really taken off. The thing is that I sent the PCM out to this guy on LS1tech to reprogram the PCM with a stock bin from a camaro with a T-56 because my PCM was from a truck. After all that all the emissions and VATS was taken off but there is no way for me to verify that the work was done.

 

Glad you figured it out. I was under the impression that VATS only prevented the injectors from working. Have you pulled a plug to verify spark? Are the coil packs getting 12 volts?

 

I did pull the plug and used a screwdriver but no spark. I checked the pink wire coming from the bulkhead and it is hot now when I put the key forward so the injectors and coils should be working. This is why I think it might be VATS .

 

The pink wire should be hot anytime the key is on. The coils are fired by the PCM by grounding them. At least that is how I understand it. This may be a VATS function. Pull a plug and stick it in the plug wire and ground it somewhere so you can see actual spark. Are you getting fuel? If you are and it is not firing, you are filling your cylinders with gas. If it does fire something could explode. You might want to consider pulling the plugs and checking them and turning the engine over.

 

No I don't have the fuel pump on right now. As soon as I saw no spark I disconnected it because I knew it had fuel going to it.

 

My understanding (pretty sure it's correct) is that VATS disables the car by disabling the fuel. If you don't have spark, then that's something other than VATS...

 

So what else could it be? The fuel is now working. I have that independent from the PCM. This is what I did. I connected all grounds, all pinks which should be the injectors and coils to the pink ignition wire that goes to my camaros bulkhead, two orange ones that are power for the PCM. Am I missing something? I checked to make sure the grounds and power lines were working with a volt meter and a test light and they are. If I'm not mistaken each coil has a control wire that the PCM sends signals so it can fire right? I tested that wire with a volt meter and a test light when I was cranking but I get no power on those wires.

 

Did you pull the engine out of a running car? or did you see it run? Verify power coming to coils and if it is and still no spark then look into the crank trigger sensor

 

I never saw it running. I just picked it up at a junkyard and I made sure it was a good motore. I will have to check the crank sensor and get back to you later today to see if it is good.

 

Does anybody know how to check a crank sensor?

 

First thing to check is power at the coils thats an easy one. Then verify thats VATS is disabled as mentioned above ( I'm pretty cure VATS cuts fuel but worth checking before buying new parts ) then to check the crank trigger...

Well... One time I thought I had a bad MAP sensor on a truck so i went to the big chain of parts suppliers that allows you to return parts if you dont use them so I bought a new MAP and I OH SO CAREFULLY hooked it up and it made no difference so i CAREFULLY unhooked it and returned it. It has to be kept in as new condition though or your fooked. Just dont tell anyone

 

But does anyone know how to check the crank sensor? The map sensor is new...

 

I think he is implying that you should go buy a crank sensor and try it. If it doesn't fix it, take it back.

 

There's a good chance that you'll have a tough time returning an electrical part. Up here, chains like Autozone, etc, offer testing of some sensors. Might be worth calling around...

Good luck.

 

As i said it literally has to appear brand new for above method to work. We're talkin the white glove treatment here. Theres probably a better way to test the thing I just dont know how

 

Oh...OK but that really will not work here in my area. Do you think I can check it with a volt metere or something?

 

Well... Its a reluctor pick up so its magnetic and they usually dont fail as in the way an ign coil fails. I dont know how to trouble shoot them but they do occasionally go for a dive. I'm still leaning towards power loss somewhere did you check for power at the coils?

 

Yes the coils have power and ground so I'm guessing that the crank sensor or cam sensor might be bad. When I get home I am going to check for power and ground on the sensors then check the control wire to see if I get volts when I crank it. Would you know how many volts the cam and crank sensor should be putting out when I crank the car?

 

No I dont know the voltage of those circuits. When it comes to wiring i'm old school. I use a test light its never failed me. 12 volts is bright , 5 volts is dim, and 1 volt you can barrrrrrely see the light. Anyways I'd worry less about what voltage at this point and simply verify continuity and power.

Oddly enough when i did my swap I took i for a dyno tune and we discovered that the TPS was not working. I ordered a new one while my dyno time was dwindling and when it arrived i dropped it on and no change. So I'm think wtf? my wiring is bad. We hack tune the thing all sorts of issues and overall a bad day.

I get it back to the shop and here whoever had owned the car before me had cut or torn off the leads to the TPS and twisted/taped them back together and put the conduit back over right up front by the sensor. Looked fine from the outside but the leads had become separated. Of course this takes me a good chunk of a day to discover and all along i thought it was something i did when here it was a problem with the harness that came with the engine.

In short when trouble shooting you have to do one thing at a time and eliminate all possibilities before moving on. Good luck

 

Ok so now I verified that the crank sensor and cam sensor are working. Something is not sending the signal to the coils to fire. I check the wires to the coils and there is ground and power but there is definitely nothing going on with the control/driver wire when I crank it. Wouldn't VATS cause that? I think I'm going to have the PCM checked because there might be somthing wrong.

 

Yeah check VATS out. I'm pretty sure it cuts fuel not spark though no?

 

I have another question about the alternator wiring. There is two wires coming out of the alternator one to the PCM and the other to gauge. Does the wire going to the PCM need a resistor? and would not connecting that wire effect it not turning on the engine?

 

Ok I still need the previous question answered if possible about the alternator wiring... I got another PCM today in hopes that would fix the problem but I get the same thing. I do have another question. Does the pink wire (ignition wire) on our cars go to an ignition relay? Does it need a special one for the LS1?

 

Just throwing this out there but does it matter what side the coils are installed on? Does it matter if the left side is on the right and vice versa?

 

what year is the harness and pcm setup for? send me your e-mail and I will get you the schematics. the alt. needs a resistor if..... it is setup as a '98 f-body. where you are feeding it ign. switched 12v. the later (99-up) is controled through the pcm with an internal resistance.

 

But does it need that connected to start?

 

no, it will start still. as for the vats at least the first several years of the ls1 (i belive the later years too) it cuts the fuel injectors. so on the first crank it will run for 2 seconds (give or take) and then die, second crank it may pop may not until you key off and wait a few seconds to crank again. which will just repeat.

it's hard to help with out even knowing the year and body it's from

on ls1tech there was a guy having similar issues as you with a caprice. he checked every wire tons of times. I forgot what he found but I belive it was a simple wireing issue he over looked each time. this was posted under the hybrid section

 

I will check when I get home exactly what year of harness I have then I will post. I posted this same problem over there and that caprice guy is helping but still no go.

 

Ok guys I finally fot spark.. I was missing two pink wires that need to be connected to the ignition. So now I start cranking it and give it fuel and it sounded like it wanted to start but then all of a sudden I can't get it to crank. Desperate and thinking it was my neutral switch I cut off the two big wires (purple and brown) and connected them but still no crank. All fuses were checked again but they are all good. What else controls the ignition and the purple starter wire? I checked the pink wire coming from the drivers side with a test light and I get no power. What would make it do that? Are there some other fuses or relays I need to check?

 

Do you guys think the new problem could be my ignition switch? Also, what fuse is the one for ignition because my fuse box is all faded and I can't see it?