Adam2001WS6

iTrader: (1)

So I had a comp cam (236/242, 114 LSA) installed in my LS6 crate engine, along with all the supporting mods. Also had 42# injectors installed. The car was dyno tuned before and after the injectors (I had them installed about 2-3 weeks after the engine install). I'm noticing that I'm getting TERRIBLE gas mileage. Granted, I understand that a cam is going to affect gas mileage to an extent, but I'm getting only 120-150 miles out of an ENTIRE tank!! And that's with normal/non-spirited driving, shifting around 2-2.5k RPMs. Is this normal? I notice a somewhat strong smell of fuel while the car is running, but I attributed that to having no CATs. Is something not right with the tuning of the car? I just feel that the gas mileage is much lower than I had expected, or maybe I'm coming to find out that I didn't have serious expectations for gas mileage after all the modifications to begin with. Mods are in sig.

Old Geezer

iTrader: (3)

Sounds like time for some data logging, and a review of what's going on.....
Also, have someone w/ a tuning suite, such as EFILIVE, pull the tune and post it for review??

Adam2001WS6

iTrader: (1)

Hmmm... Now to find someone in the area with the ability to do that...

atrain59

iTrader: (31)

Something is way off, a cam should not make you lose that much gas maybe 2-3mpg. I would have your tune looked at again. Check and see if they put in the right info when the swapped the injectors out, I had this happen to me and it made a big difference. I was getting around 190 miles on a full tank and after I looked over the tune I noticed the injectors were not set up right fixed it and I get 220 miles on a full tank. Not saying it's your problem but could be.

turbolx

Step 1) Read up on end of injection timing and how it applies to bigger camshafts

Step 2) Start on a new tune for the car using knowledge from Step 1.

Frost

iTrader: (45)

I take it that he has someone else tuning on the car.


OP - I'm only about an hour away from you (with no 95 traffic)

Adam2001WS6

iTrader: (1)

Frost, yeah I've already checked you out and I have been looking to set up some time to come down and get you to have a look at it. Funny that you jumped the gun on me and initiated contact! Haha

Frost

iTrader: (45)

Honestly, when mileage is bad, the front O2s are suspect. They control most all of your fueling except for first startup and WOT. If they are bad (the don't always code) or if you have leaks near, around, or upline of them, mileage can really suffer.

James Linder

Have Frost set your injector tables in the PCM to the correct values. These are obviously not set correctly and the injector pulse widths are too long for the larger injectors. If you did not touch the injector table to correct these values for the larger injectors then way too much fuel is being injected at all times regardless of RPM.