eviltwin_1987

iTrader: (18)

before: I was having a problem where the nova stopped running and wouldnt start again. no spark, no injector pulse. I had build the harness my self. I changed every single sensor with one off a running truck. still nothing. tried different ecm to no avail.

Now: I kept on thinking it was my harness so we got a new professional built stand alone harness. Put it in and it started right up. Started multiple times throughout the afternoon. Last time we started it, it just stopped running. Now no spark, no injector pulse, and I cant connect to the ecm. i tried two other ecms and still nothing.

So WTF is wrong with this thing?

Spike-Z

iTrader: (2)

Grounds? How many do you have and are you sure they all are tightened down?

chevellepowered

iTrader: (37)

i would just check fuses,
all connections..ground and positive,,but you probly already did that,,right..
i think your def not getting any power/ground to ecm, check from there

electrical is pain,,

Pocket

iTrader: (22)

Start there. Check PCM power and grounds first

eviltwin_1987

iTrader: (18)

i have checked all the powers and grounds. I literally didnt change anything from it running to not running. I cant work on it again until friday but i will be added ground and ground from the battery directly to the block. I truely hate this car

1CAMWNDR

iTrader: (21)

Electrical gremlins are the gear head's Ultimate Nightmare.

the_merv

iTrader: (88)

Sounds like something burned up..hope you get it worked out.

MeanYellowZ

iTrader: (19)

Don't let it kick your *** man, sounds like what I like to call, "new pair of eyes syndrome" You know, and I know it's probably something simple thats getting overlooked. The more it aggravates you and the more you think about it, the easier it gets to look past something simple. I do it all the time, and often someone will stop by with a thought/ idea from a different mindset and many times it solves the problem and you laugh about it afterwards...give it a few days. We both know it's no secret underhood ninja....make sure you let us know when you get it and you sit back to enjoy an ice cold one!

Pocket

iTrader: (22)

That doesnt mean you didnt pop a fuse or something. They're quick tests with a multimeter

gofastwclass

iTrader: (2)

Agreed.^^^

I drove for months after a conversion, then blew a fuse that shut me down. Traced it to my fuel pump relay, replaced the fuse drove another 2 days, popped it again. Cleaned grounds, replaced the relay and haven't had a problem since. Bad grounds can cause weird problems.

I learned in the car audio world that self tapping screws are NOT good grounds.

Najania

As an experienced mechanic i can not stress how important grounds are..

Take a multimeter and measure the loss of voltage on both the plus and minus side of the ecm and make your way through the wiring, fuses and relays. "simple as that"

the_merv

iTrader: (88)

It's not the screws..it's the surface you use them on..if you screwed into bare clean metal then you would be good.

pdsq98gt

Possibly a bad ignition swtch not powering up the pcm.

eviltwin_1987

iTrader: (18)

I have checked all the battery leads and ign to the ECM. They are good. I am going to put on some new grounds and see what happens

Qwiknotch

Put a carb on it... LMAO ... j/k

brandon1566

did you have the security taken out the new ecu? I know I had to have mine programmed before it would start