As of this past Sunday afternoon, I became the PROUD owner of a 97 Z28 M6... AND I LOVE IT!!! despite all its strange quirks (gas guage doesnt work at all, oil pressure gauge doesnt work... etc.) its one of my most favorite vehicles ever... wel... up until yesterday afternoon... The owner before me replaced all the factory stereo with a new head unit and kicker speakers all around, and the deck alone wasnt enough to run them, so he had pre-wired the car to use an amp... The only problem was he sold the amps and subs he had in the car prior to me buying it, so I had the fun task of hooking a new amp back up... Something simple for me cause I've been doing that for YEARS... I disconnected the positive terminal from the battery and put the amp power wire on (yes, it is fused) and now the car wont start... Im guessing it has something to do with the computer, but its only a guess... It turns over like nobody's business and I have fuel to the rail, but it sounds/feels like the injectors arent opening up... I've read a great number of posts and all the help stops when someone suggests getting a "noid" checker for the injectors... and Im sure I can go get one, but what do I do after that?? It had an aftermarket alarm on it at one point, but I had a guy uninstall it... yes he hooked everything back up to factory and whatnot... And he only uninstalled it because we thought it had something to do with it...

I NEED HELP!!! I have the car for 2 days and its doing this?? I dont want to get rid of it, I LOVE IT!! But I've gotta be overlooking SOMETHING!!

 

check your fuses. fuse box on the side of the dash and in the power box under the hood on the driver side fenderwell. not sure on the 97 but on mine theres two fuses for the injectors and a ingition fuse that u need to check. could pick up a noid light and see if the injectors are being told to shoot the fuel. try spraying some fuel in the tb and see if it tries to start and/or pull a plug wire off and stick a screwdriver in the end and have someone turn the motor over while holding the screwdriver close to a ground to see if its sparking. need to find out if its a fuel or spark problem.

 

i had a simmilar problem make sure your amp is 130% grounded! i had the problem of not being grounded enough and i started popping fuses like it was my job.(i lost dash lights, headlights, tail lights, everything and i had to start replacing practicly all my fuses) make sure everything is grounded and make sure you havent blown any fuses...

 

Ok... Im having my Dad bring home a plug tester from work to see if Im getting spark, didnt try spraying gas into the TB, but I'll try that one first... I've looked in both my fuse boxes and found nothing for Injectors... not to mention all the fuses in both boxes are good... So Im wondering if the injector fuses and relay's are somewhere else... like fuseable links or something... If anyone knows where they are I'd appreciate if you could tell me... Im going to scower the net and see about finding a wiring diagram... I may not get to mess with the car today because of the rain, but there is always tomorrow...

Also, I've read alot on the net and some say it points to the VATS... I REALLY hope it doesnt, cause either way you look at it its gonna be expensive... To fix OR to completely disable it... Do my "symptoms" fit the explanation? I know Im probably jumping the gun, But I've gotta wonder....

 

Im about 99% sure im 100% grounded... The first ground wasnt worth a crap... it wasnt a ground at all.. They used the bolt to the rear shocks and it was painted... absolutely NO ground... So I moved it... But I'll ask to be safe, whats the best place to ground to? There is a support on the passenger side behind the spare that I grounded to... Im thinkin that I may have arched the power wire when installing it because the original owner had a piece of heavy gauge wire in it under the fuse so that it would ALWAYS have power... I took that out because that COMPLETELY dissolves the reason to have a fuseable link anyway... some people....

But if where I said isnt a good ground, what would you suggest?

 

Hooking up your stereo should be a different thread than your car wont start.Two seperate issues but perhaps related.Anyways for some good info,wiring diagrams,part id and etc check out shbox.com.very informative.

 

You can rule out the VATS. If it was that, the engine wouldn't turn over at all and the security light in the dash would be lit.
And I don't see anywhere where you said that you disconnected the amp wire again from the battery cable. Did you take the amp wire back off to make sure it isn't the problem? The one thing you changed was to hook up the amp. It's very possible that wire is shorting, or already did short something out.

 

Im actually glad you pointed that out... I got so carried away with what it was doing that I didnt say what I did... I did, in fact, disconnect the amp wire... As soon as it wouldnt start I figured the EXACT same thing... Undo what seems to have caused the problem in the first place... but still nothing... And I ruled out VATS as well for the same reason... So now I've gotta figure out what I shorted out... The weather isnt permitting me to go out and figure out if Im not getting spark or Fuel... I've never had a problem working in the rain, but when it starts getting cold forget it... SOOO Im going to put off working on it til Saturday when its supposed to be Sunny... First thing Saturday morning Im going to figure out if Im getting ANY power to the injectors... I was told that they should ALWAYS have power to one wire if the key is on... I hear there should be a fuse for the injectors and a relay, but they are in neither of the fuse boxes I've seen, so I'll have to search all the way back to the computer where it should be getting the signal in the first place... Im getting more and more convinced that its probably a computer problem and that I shorted something out in it when I hooked that amp wire up... I noticed that the previous owner had it wired to always be hot by putting some heavy wire in the fuseable link underneath the fuse... so even though I pulled the fuse, it could have arched somewhere accidentally... I only wish this weather would have waited til the weekend... If I figure out what it is/isn't this weekend I'll post... Im doing all my research now so that I'll be semi-prepared... Someone also said that the Optispark may have shorted out... They they are so finiky and frail that they tend to do that a lot... I guess if Im not getting spark, that would be the first place to check, huh?

 

this is a connection because as soon as i hooked up my amp (which wasnt grounded correctly) i lost everything that was electrical... nothing happened and then fuses went like popcorn.

i hooked mine behind a custom box down behind the rear driver wheel i think i have pics of my boxes on my profile... but there are some bolts down in there that are fairly easy to ground to or the rear shock tires right behind the seat belts but be carefull with those that you get them back on tight or they might back out and that could be really bad!

 

Actually the previous owner had them grounded there on the rear shock towers and I wasn't getting a ground at all, but there is a support bar behind the spare tire that I used... Once grounded there I knew I had a great ground... Yesterday and today have been a little wet, so bright and early tomorrow morning I'm gonna go tinkering on it... see what I can get done... I'm keeping my fingers crossed that it isn't the brain... I'll definately lt y'all know how it goes!!