Oddballcustumz

I purchased a 98 camaro that has a LS6 blocked 383 stroker with a FAST 90 intake and throttle body that I wanted to use on my stroker engine so I swapped out the intake for a LS6 intake off mine and now it will not run right it sounds like it's misfiring and kicks up and down in idle roughly 500 rpms

I let the 42lb injectors with that motor as mine was tuned and ran strong with the 32lb ones so I decided to leave them

Any ideas or is there that much of a difference between intakes ??

Mercier

iTrader: (15)

I cannot tell from your message if you changed the injectors. Did you ONLY swap the intake and nothing else, or did you swap injectors, throttle body, MAF, or anything else?

There should be a decent difference in flow between a stock LS6(smaller TB opening right?) and the FAST with 90mm TB.

Crousti

You can't change injector sizes without a new tune, so if you went from 32lbs to 42lbs, you are pouring fuel in there and bore washing your engine. With enough bad luck you could hydrolock the engine and say goodbye to the rods. On the other way around, you would be running ultra lean and it wouln't work well either.

But you may also have something leaking. Maf based systems absolutely hates air leaks past the maf and usually exhibit that behavior. Maybe there is a specific issue on LS engines, but these 2 are common issues on all maf based systems. The injector size difference is actually a problem on all engine control. The intake flow difference would be a problem on an alpha-N system only, both maf and map+iat can handle it (although an increase in power would be seen with a proper tune, it won't prevent the engine from having a smooth idle)

garygnu

you took off a fast 90 intake ,and swapped on a ls6 intake ?the motor will run different ,it was tuned for the fast intake and the matching TB .I hope you didn't swap injectors with out a tune .