1G leaning out as soon as i hit the gas

[jason91dsm]

ok so here is my setup need some help
big 20g with tubular manifold
2' 3/4 exhaust
stage 1 frankenstein bored .40 over
stock head and cams
750cc injectors
255 lph fuel pump
aem wideband
apexi safc2 controller

problem: just installed fresh rebuild now when running at idle runing alittle rich but as soon as i hit the gas it boggs to the point it wants to stall and peggs dead lean as soon as i get off the throttle rpms come back and goes back to rich it doesnt matter if i try wot or ease on to the throttle same results all apexi settings are zeroed out

 

[jrohner]

What AFR, and how do you have the SAFC tuned? Are you data logging?

 

[pos4g63]

Does your frakenstein run 2g pistons with higher compression? If so you deffinitly need some kind of data logging and tuning software as the 1g timming maps are kind agressive for the higher compression. Also safc is proly not the best choice to adjust your fuel at this point.

 

[Cassanova122407]

do you have a afpr

 

[kzoosho]

Are you using a nb or wb02? are u sure the settings are correct in the SAFC?? whats your base fp also.

 

[jason91dsm]

my afpr is set to 35psi and like i said the safc2 is zero all the way across the board high and low throttle it will not let me rev on it AT ALL i hit gas it wants to die and wide band wont even register it after 18 and it peggs there instantly

and yes it has the 2g pistons

 

[Colt4G63 also]

Check your sensor readings; it sounds like maybe a TPS issue.

 

[eclipsetuner_21]

check your fuel filter, it may be clogged

 

[donniekak]

You are ruining your new engine. I bet the cylinder walls have already been washed out, and glazed. Not to mention the fuel in your oil, and possibility of spinning a bearing.

Running 750's with no fuel compensation is just dumping fuel into the engine. To the point it wont even burn, and is causing the wideband to peg lean from 0 combustion of oxygen. The sensor reads oxygen, not fuel, so blowing unburnt fuel out the exhaust shows as lean, just like wot misfires.

Put the stock injectors back in, a safc wont compensate properly for 750's anyway.

 

[jason91dsm]

I have only run the new motor for about ten minutes, Ill throw the stock injectors back in now and see what difference it makes. Thanks

Ok so i checked the TPS sensor and fuel filter they are both ok. I also switched back to the stock injectors and it is doing the exact same thing.

 

[jrohner]

Is your airflow reading correctly? What Hz are you reading at an idle? It almost seems like the AFC is hooked up wrong.

 

[vteckiller2000]

Running 750's with no fuel compensation is just dumping fuel into the engine. To the point it wont even burn, and is causing the wideband to peg lean from 0 combustion of oxygen. The sensor reads oxygen, not fuel, so blowing unburnt fuel out the exhaust shows as lean, just like wot misfires.
.

No.

OP, how did you install your fuel pump? Did you use submersible hose? Stock lines and hat?

 

[jason91dsm]

I figured it out it was a bad MAF sensor thanks everyone