PCM starting issue
Thread Starter
Staging Lane
Joined: Dec 2019
Posts: 54
Likes: 5
PCM starting issue Hi so long story short this is my first build and I'm learning lessons the hard way. 64 nova with ls1 mild engine build. Got the motor to start after getting it all together. Speartech built harness and pcm startup tune on cammed motor with LS2 dbw tb ect. Have to hold pedal down a little to get it to stay alive. Nbd I know I need Dyno tune.
My problem is I accidentally crossed polarity on battery for a solid 10 seconds and let the smoke out of the alternator and charging cable. Stomach turned inside out but after properly setting up, the engine started reluctantly. Sounded like garbage compared to previous runs. After a week or so it won't even run and pops and backfires. So I replaced the new Holley 150amp alt and charging wire with exact same setup. Still won't start and just kind of limp fires and backfires as if timing is way off. Pulled PCM and ready to send off for inspection.
Am I right in assuming PCM is probably toast? And if so, any good recommendation on remote startup tuners? Not able to take to Dyno yet. Any help is appreciated.
My problem is I accidentally crossed polarity on battery for a solid 10 seconds and let the smoke out of the alternator and charging cable. Stomach turned inside out but after properly setting up, the engine started reluctantly. Sounded like garbage compared to previous runs. After a week or so it won't even run and pops and backfires. So I replaced the new Holley 150amp alt and charging wire with exact same setup. Still won't start and just kind of limp fires and backfires as if timing is way off. Pulled PCM and ready to send off for inspection.
Am I right in assuming PCM is probably toast? And if so, any good recommendation on remote startup tuners? Not able to take to Dyno yet. Any help is appreciated.
TECH Fanatic
Joined: Dec 2017
Posts: 1,467
Likes: 265
From: Bossier City, Louisiana
Can you talk to the PCM through any kind of code reader? Of the six PCM devices I have around here (five from the junk yard), I've yet to see one go bad. They seem to be durable and hard to damage.
Rick
Rick
Thread Starter
Staging Lane
Joined: Dec 2019
Posts: 54
Likes: 5
Unfortunately I lent my code reader out some time ago and never got it back. But I will see if I can get ahold of one and try that before sending out to someone. I'm considering getting hp tuners but tuning software isn't my strong suit and I haven't looked into the learning curve enough to feel confident purchasing it.
