Lots of problems with C5 (Please Read)

[dville_gt]

Went to tune a local guys C5. Car turns out to be a bit of a basket case. He had a "friend" build the engine for it, and from what I can tell it is a:

Stock bore 346 LS1
ported heads (who knows)
236/242 .580/.590 112lsa cam
headers and off-road x pipe
stock ls1 intake
stock injectors

pulled the tune and it was stock, so i put it into speed density and pulled a little fuel out of the entire VE as he told me it was running super rich. car would start but had very little vacuum (idling ~75kpa)

Tried to get the RAF dialed in with the RussK file, it wanted 3.5 to 3.0g/s as it was warming up. Still pig rich.

Tried everything I could to lean it up and it wouldn't make a difference. I eventually had the VE at low RPM's in the low 20's and it was still reading 11:1 and fouled the plugs out. Put a new set in and it started up but still wouldn't lean out, eventually fouled out those plugs as well.

Come to find out the car is missing 2 intake bolts (first bolt drivers side, 2nd bolt passenger side), and the owner said he saw smoke coming from bolt of the holes where the bolts should be. I know it is common to port into the rocker bolts, but never seen anyone port into the intake bolt holes, but can't imagine how else this would be possible (unless the intake is cracked).

So in summary I've got a C5 that is running crazy rich, low vacuum, fouling plugs, and cannot lean it out. Any tips?

I told the owner to pull the intake and check for cracks and inspect the heads, then put it back together with all of the bolts, I also asked him to check the fuel pressure via a gauge.

Thanks!

[JamesLinder]

at least put on an LS6 intake with larger fuel injectors for this cam and heads combination. Surely not using stock throttle body with this set up because it would be very restrictive if so. I would not disable MAF if it were me; it is more difficult to perform speed density tune than MAF tune. I would compression test every cylinder before I did much of anything actually to make certain the rings are sealing, otherwise you would be wasting your time doing anything if it does not have reasonable compression. If you have good compression then for certain verify the IFR tables are set correctly for the injectors in the motor.

[sarg]

How much overlap on that cam? Possible it needs the injection time adjusted some? Did the timing chain get installed correctly? Honestly though, until it has all those issues done and has been checked head to toe, I don't think I would touch the tune.

[edcmat-l1]

Data log and a tune. No use even responding if you don't post them.

If you're pulling a bunch of fuel out via the VE table, and it's not leaning out, then you probably don't have it in SD. Again, if you post a data log and tune, we'd be able to see that.