My dads 73 swapped Camaro issue

[Hpsonny]

Hey everyone, I'm having a little issue with my dad's Camaro I swapped a 5.3 /4l60 combo in. So, it started to do a backfire through the exhaust on some mild to moderate acceleration. I called my tuner who is somewhat local to me, had my dad drive it down there where they went for a drive retuned it and fixed its issues he said. My dad drove it home and was going by my house when the problems came back, I drove it and it felt like he didn't do a thing to retune it however my dad said it was totally fixed when he was there .. only when he came back this way and got off the freeway it started to act up .. When I drove it, it backfires and breaks up but more throttle and over 4k I'd say it clears up and is fine. even on a cold start, I drove it and it starts to break up at about 30 to 50% throttle. My question is what could this be and what should I be looking for and logging in the Vcm scan? Before you guys get on me about posting the tune Yes, I can post the tune, but I need to get down to his house with my laptop 'I was more curious to see if this is an off the top of your heads issue like a bad 02s etc. . I just don't know on this one ..

73 Camaro
60e
5.3 lm7 cam only
p59 ecu

Thank you for the insight in advance

[gtstorey]

Without the tune and log it will be a wild a$$ guess. To many possibilities outside of the tune that will make it randomly "break up" to do any good throwing out guesses.

[edcmat-l1]

Plug wires not snapped on all the way.

businessman-looking-into-crystal-ball.jpg


That's what this said ^^^^

[gtstorey]

Plug wires not snapped on all the way.

businessman-looking-into-crystal-ball.jpg


That's what this said ^^^^

I think you need to black it out and paint an 8 on it. Although the younger users might not get the reference.

[Hpsonny]

Plug wires not snapped on all the way.

businessman-looking-into-crystal-ball.jpg


That's what this said ^^^^

Hey Edwin we changed the wires and plugs on it before he went down to the tuner .

[gtstorey]

Hey Edwin we changed the wires and plugs on it before he went down to the tuner .

Doesn't mean they are snapped on good.

[Hpsonny]

Doesn't mean they are snapped on good.

I bottomed them out and it takes some force to get them off

[gtstorey]

I bottomed them out and it takes some force to get them off

It was just a random guess only. If he had used the Magic 8 Ball instead of the crystal one, it would have probably been right.

[edcmat-l1]

It was just a random guess only. If he had used the Magic 8 Ball instead of the crystal one, it would have probably been right.

lol

[abc]

There is no one thing that's a given that will cause the symptoms you are describing, it's gonna take proper diagnosis to know for sure. On here your gonna need to start with sharing the tune file and log to get help.