I'm at a loss. someone help with a stalled and cammed G8 please.

[G8GTNOOBIE]

something just seems off to me and I cant figure out what it is. everything I seem to adjust doesn't seem to do anything. cold starting and backing out the driveway if I blip the throttle it will want to die or even sometimes die. driving down the highway today it was running good. on my way home it was running rough down the highway I have no idea whats wrong with it. it was tuned but not by me and will not say who tuned it either. it has a circle d stall 258mm single disc, milled heads .035 stock thickness head gaskets ported intake and TB roto fab intake with ls7 maf e85 flex tune but currently been running just 93 with decapped stock injectors long tube headers cam is a 22x-23x 111+2 lobe separation angle.

[5FDP]

If this goes over your head I'm sorry but that fuel injector data is all fucked.

The flow rate is maxed at 63.5, not good. The stoich table was scaled by like 1/4 or something for whatever reason.


Whoever did this must not know what to do there. If the flow rate is above the maximum allowed value you have to double the stoich table and half the flow rate and IVT terms. I have no idea what decapped injectors flow but surely it's far above 63.5lb/hr.

If you want to fix it right, you need to input the flow rate that is correct for the injector size and for the fuel system you are running. If the fuel system is still stock, the injector flow rate will still be sloped and not a solid value all the way across.

Without a stock tune, I have no idea if he fudged other numbers in the injector data to make it run. Ideally you want good injectors and not de-capped.

The flex fuel sensor will do the work for figuring out the correct stoich ratio based on alcohol content in the fuel.

Start with better injector data, then re-work the airflow model with your wideband o2 sensor. Most things get way better if fueling is correct. Making timing and idle airflow changes much easier.

[G8GTNOOBIE]

thanks for your help. was told the injectors I have are 85# I added a stock tune file

[5FDP]

Yup, lots more was changed from the looks of it.

Min injector pulse was cut from .750 all the way down to .125.

Short pulse adder was also cut also cut just about in half.

Injector timing as well.

Some of that data should not have to be changed because the injector itself did not change. A mod to the injector tip was done to make it spray more fuel.

If it was me, I'd go back to square one with most of this, change what I know needs to be changed and work it over again. I'm sure some injector timing may need work because of the decap and of course the MAF and VVE need to be gone through to make sure the rest of the fueling is on point.

[G8GTNOOBIE]

thanks for your input. much appreciated so far