I finally got my 350 swapped in, and it's not acting like a 350 should. It's only powerful at about 1/3 throttle, and even then it's not nearly as powerful as it should be. At WOT the engine revs to 3 grand, but my tires do absolutely nothing, it's almost like i'm slowing down. At idle it'll run all right, but when i'm driving and slow to a stop it dies, but I'm guessing that's a vacuum problem. I still have the stock ECM, but I don't think my mods are extreme enough to trip it up that badly. But still, vac and ecm problems shouldn't affect my WOT that much, right?

 

What's the build up?

Many times, new motor + ECM = tuning.

 

Are you asking about what mods I've done? Because other than what's listed in my sig, i haven't really done anything. I definitely have a vacuum problem though. I have to practically stand on the brakes at low rpm's. Would a vac leak cause me to have absolutely no acceleration up high?

 

So no one knows anything about the effects of having no vacuum on higher rpm's?

 

A vacuum leak will not affect WOT. Think about it..... at WOT, there is no vacuum anyway, so nothing extra gets sucked in.

A vacuum leak will affect idle the most of all, and cruise next after that.

Having the ignition timing set wrong (specifically, way retarded) will cause all of what you describe.

You didn't by any chance put an aftermarket timing cover on it, did you?

 

No aftermarket cover, however there is a slight chance i could have my timing off. Just so I'm sure, this doesn't sound like a tranny problem does it? because i just installed a new converter.

 

Check your timing first. Make sure you do it right, with the little connector disconnected; and make sure you plug it back in afterwards.

 

I tried switching all of my wires 180*, just in case i was dumb enough to set #1 firing at 6. Wouldn't even start, although I didn't disconnect the timing connector in the process, would that have mattered? It turn out i had the wrong runner-manifold gasket, so that could be a big part of my vac problem. I'm using a SD intake with a MAF harness, so i wasn't able to connect to the EGR like the ECM wanted. Would not having the EGR connected cause me to have absolutely no power at WOT?