ignition problems???

I got a 1996 4x4 2.7L. It'll crank up but as soon as you turn anything electrical on (headlights, backup lights, stereo) it kills it. the battery and altenator are fine. I thought it was the igniter but put a new one in and it still don't work. My next move was gonna be ignition switch or the engine harnass but both of them are real expensive so i figured id ask around first any ideas??

 

Are you sure the battery is fine? It sounds like you're only running on the alternator.

 

Honestly, I think you're a bit beyond your capabilities here. I'm not entirely sure how you think the ignition switch could be related or why you replaced the igniter when the engine is running fine until you turn stuff on. I'm not sure your logic in replacing the harness either, unless you suspect there's a short, but then you'd be tripping fuses before the engine dies.

As Dave said, It really points to an alternator and battery issue. Maybe a ground issue.

Any engine codes?

 

X2, the batt could seem "fine", but your amps could be shot

 

i took it to auto zone and the battery and altenator are fine all problems pointed toward the ignitor the computer read a p1300 ignition circuit malfunction im no expert but i know when i got a dead battery/altenator.

 

yeah p1300 i know im beyond my capabilities or else i wouldn't be asking for help haha but i recently bought it and the harness is ****** rigged together thats the only thing i can think of (-igniter) for the code given. i tried several different batteries and none of em made a difference.

 

As mentioned above, it is probably a good idea to check your grounds.

 

When the engine is running, does it run well? When it does die, is it an instant death like you turned off the key? or is it more like its trying to keep going and sputters out? Any difference if you keep the engine at about 2500 rpm when turning something on? Is it anything that will kill it, or maybe just fuses in the interior fuse box?

Is there any chance that someone bypassed a fuse and there's a major short? There really aren't that many major wires to deal with. Follow the ones off the alternator and the starter, as well as the off the battery itself and around the engine fuse box. If its a short problem and killing your engine, thats a good place to start. Double check all your fuses to make sure someone didn't just bypass one with a wire.

Any issues at all with the engine off, ignition to accessory, and you run those items? Have a 10+ amp ammeter you can pull a fuse and test the amps for each item? A 10 amp ammeter wont help much for running the engine, but should be plenty to diagnose an accessory problem, one at a time.

But again, double check your grounds as well, as a weak ground could very well be causing low voltage to come off your alternator or battery, killing everything after it reaches a certain point.

Anyway, tons of different things for you to check into, mostly dealing with wiring and shorts. If something is causing the ECU, ignition, or fuel delivery to short out, I could easily see it causing the engine to die. Trying to track down just where that is happening is usually the trick. Being able to narrow it down to a certain fuse or even just a few accessories helps things drastically.

 

it runs great til you turn stuff on. There isn't any difference when its revved up and it kills it instantly like i just turned it off. The grounds are solid, but i haven't checked the fuses yet. Also all the things that kill it work fine with the engine off. But thanks for the help ill let ya'll know what i find. this ones kinda makin me wish id just dropped a new engine in my 1990 yota 4x4 haha