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burnt up ECU?

Posted: Sun Nov 06, 2005 1:53 am
by scuzzy
Allright, so I was pulling the engine today, the intake manifold was off the old block, I was mating it to the new block and all that goodness.

during this period, it became dark out, all the windows were down on the car so I decided to drop the battery in and roll the windows up.

put the battery in, made sure about the connections so I wasn't going to short anything. the engine wiring harness wasn't connected to anything, but anyway.

put the key in, turned to 'ON' didn't get any dash lights (headlights were off), no oil pressure or anything, but I didn't suspect anything at all due to the harness being disconnected.

what worries me is what happened after I cut the ignition off. the check engine light came on fairly dim and it pegged the engine temperature gauge.

I didn't notice any other lights at all, the first thing that came to my mind was an ECU short, so I jumped out and pulled the connections on the battery (they wern't tight, just set them on)

sat in the car for a minute, didn't smell anything odd. I won't bother to hook anything back up till I get the engine in tomorrow.

I guess this question is for vrg3, what's the chance my ECU fried because the engine wiring harness ground connector wasn't hooked up?

Posted: Sun Nov 06, 2005 3:29 am
by scuzzy
I believe it's worth mentioning I had the block (minus intake manifold) still in the car.

the only sensor that was hooked up belonged to the coolant temperature sensor I believe. a fairly wide sensor submerged in the block on the right side (facing the block from the front side) behind the coolant output tunnel on the top.

one wire to it, white.

that could explain the coolant temperature sensor pegging.

I'm glad I didn't notice any smoke pouring, no fuses popped that I'm aware of.

hopefully tomorrow it will start just fine.

Re: burnt up ECU?

Posted: Sun Nov 06, 2005 4:42 am
by A_DuB
scuzzy wrote:the engine wiring harness wasn't connected to anything, but anyway
Your going to need the harness in and conneted up. When I took my intake manifold off for the knock sensor (you can read about it in one of my posts) and painted my manifold, the ground for the wirering harness on the manifold came lose on me, another long story, anyway it peged the temp gauge and made my weak but once I figured it out it started right up.

Posted: Sun Nov 06, 2005 5:48 am
by vrg3
So you turned the igniton ON, and nothing happened?

Then you turned it OFF, and the CEL lit dimly and the temperature gauge needle moved to the red?

And it stayed that way for a couple of seconds?

And then you disconnected the battery and it went away?

Chances are you're fine, in any case, especially if you didn't smell any magic smoke.

Posted: Sun Nov 06, 2005 5:57 am
by scuzzy
vrg3 wrote:So you turned the igniton ON, and nothing happened?

Then you turned it OFF, and the CEL lit dimly and the temperature gauge needle moved to the red?

And it stayed that way for a couple of seconds?

And then you disconnected the battery and it went away?

Chances are you're fine, in any case, especially if you didn't smell any magic smoke.
yes sir, the couple of seconds was only due to the transition time from me jumping out of the seat and running to the battery. the second I saw the CEL light up and the gauge rise, I knew it was bad mojo and made haste to disconnect the power.

nope, no magic smoke smell.

Posted: Sun Nov 06, 2005 6:05 am
by vrg3
Huh. Well, it's weird and right now I don't have the energy to figure out an explanation... but I don't think that's necessary anyway.