i just did a lq4 4l80 swap into my 1986 c10 and i removed the vats and then the truck fired right up but then dies after about 3 seconds then after like 2 or 3 starts it wont start unless i clear the dtc and it starts rough. sometimes i can get the truck to stay running as long as i keep the rpm above like 3k but as soon as i let off the throttle it dies like the fuel injectors are being cut off. im really at a loss here. the only code it is really displaying is p0641. can anyone point me in the right direction. i can post picture of the vcm scanner while the truck was running if need be. Thsnks alot