lt11994

I finished up my cam swap today (1994 Camaro Cc503 cam) and I just had enough time to start it before work. It fired right up and idled. However I noticed I am getting a significant amount of raw fuel out the exhaust and I'm not sure of this is a characteristic of the cam or not but it seems rough when I rev it. I'm thinking I have a plug wire crossed or an injecter wire crossed. Any other ideas? Thanks guy

RamAir95TA

iTrader: (2)

Was the PCM tuned for the new cam?

lt11994

No it isn't didn't yet

ahritchie

iTrader: (1)

Lol...ditto. I've had/have this issue with both my LT1 builds. I too wonder if this is "normal" or not. Old cam only (lunati voodoo 60121) setup would spit raw un-burned gas with PCM for less tune....after a dyno tune with part throttle tuning seemed to make it somewhat better ; it still smelled like a pre-1971 muscle car (no cat)....I just figured that is normal with a bigger cam

New 383 combo with lunati voodoo 60122 also spits raw gas; especially when just started cold. I figure I will wait and see what my dyno tuner can do (this one also has PCMforless tune for now). It's only been getting 11 MPG; but that is beating on it in city driving with 4.10 gears...Otherwise, driveability and power are on the money; how does your car drive? Should be a significant power gain from the cam swap...

lt11994

I havent had the chance to drive it yet I'll have to see when I get home. The raw fuel just scared me

RamAir95TA

iTrader: (2)

If you don't have it tuned you shouldn't be running the engine. Dumping that much fuel into the engine is not good. Stop running it.

You have completely altered what the PCM "thinks" it's seeing by changing the valve events and fueling requirements. You can't expect it to run properly until you have it tuned.

lt11994

Well I ran it around the block just to see and it started backfiring and barely made it home. It ran terrible. I think we are looking at more problems than a bad tune at this point. It stalls and pops and runs like garbage. I checked my plug wires and injectors and they all seem fine. Idk where to go

VinR1

iTrader: (17)

...you ran it anyway

Dont touch the ignition without a tune. I'm certain that'll clear up 95% of your issues if not all.

lt11994

Ok. I'll send out the computer tomorrow. I guess I just didn't think the 503 was a big enough change to make a car run THAT badly.

RamAir95TA

iTrader: (2)

Heed the advice instead of ignoring it before you do some damage.

The stock cam is like 202/207...the 503 adds 20+ degrees of duration and almost an additional tenth of an inch in lift - it's a huge difference from stock.