No start....where to start

blowby · March 5, 2007

Ok here goes....

I'll admit up front that I'm new to the newer GM's. ('80's and older I'm fine)

Mostly a Ford guy, but I do love my Sub.

Please forgive me if I ask some seemingly dumb questions as I learn more about the emgine systems on this thing.

I have a 1996 Sub. with 5.7 vortec. 238k on it and up until a few weeks ago it was running fine.

Truck had a recent "tuneup" just before I bought it,(1yr ago) looks like new plugs and wires for sure.

It met Penn. State emissions.

2 problems that occured together and I'm doubtful they relate but maybe, so I'll describe both.

By the way the SES light never came on nor flashed.

1) The engine recently has had some intermittent "hard starting" issues...they seem like the timing is off, by the way it turns over. It did that a couple of times but with a little persistance the truck wuld start and then run fine for a month or so before it did it again.

This has happened 3x, the last time is where i am at right now.

It cranks hard and then freely as if the timing is being adjusted as it is cranking.

It pops and backfires through the TB, but will not start.

I can hear the fuel pump running and the backfiring would rule out a fuel supply issue.

2) This is the second issue, that occured just a couple days before the final truck restart issue.

The Brake system seems to have a short?

Headlights off:

Press on the brake pedal and the parking lights and guage lights come on.

The left turn signal will not flash but stays on (left only, right is fine)

Cruise will not work.

Headlights on:

The 3rd brake light stays on, left turn signal still wont flash(right side is still fine), but cruise will work.

Any help is appreciated.

thanks,

Bryan

RCH · March 8, 2007

This may sound stupid, but it sounds like a wire or wires are shorted out because it is intermitent. I think I would pull the lower cover under the steering column to see if somebody has messed with something(Wiring) down there. you say you recently purchased this vehicle, the person you bought it from may have removed something he wanted to keep, and didn't re-wire it correctly. Hope this helps. This is a tough one.

If you can still contact the person you bought it from, maybe he can tell you something that might give you a direction.

blowby · March 12, 2007

Thanks for the help...

I can't contact them anylonger.

There is an electric brake controller installed I was going to start there.

I'll let you know what I find.

The starting problem was due to the good ole' cap and rotor....

I replaced them and that did it. They were a bit corroded, after 20k miles.

Not GM's greatest design..

Anyway, glad it was an "easy fix",

Kinda surpised that a cap and rotor could cause the symptoms I was seeing.

But now I know.

Bryan

asilverblazer · March 12, 2007

I would replace the dual filament bulbs in the back if the filament breaks and falls on to the other filament, it can back feed the other lights in the circuit. The brake light filament breaks falls contacting the parking light filament, thus put your foot on the brake power goes through the brake light circuit to the rear brake light and via the filament to the parking light circuit which includes dash lights. Didn't read carefully enough the other lightinh problems to see how they might play in to the mix but thats where I would start.

OK I reread it again, and still suggest the bulb, parking lights are feeding the third brake light, and so forth... If not the bulb wires could be contacting some where.