I just recently swapped in a 383 and put the stock TPI on top. It currently has a stock 350 chip programmed for 24lb injectors, but I still have the stock 19's in(long story but the 24's I had didn't work) The car runs awesome for the initial 4 minutes or so, will roast the tires at 30 in OD and the front end lifts when you punch the gas .... then after that it struggles. I would assume that it starts to struggle when it goes into closed loop. I know I should get a chip burned and get the right injectors in but is there any way to set it up so it stays in open loop or a way to make it run like it does in the first 4 minutes all the time?

 

Just don't do it, that's bad! Get a set of LS1 injectors they'll work set to 24lbs.

 

If you want it to stay in open loop, just unplug the 02 sensor. It will have no other choice. However unless your 02 sensor is bad I don't think that will solve your problem. It is one of the few sensors that should be accurate still even after swapping to the 383.

 

Closed loop is not your problem it's the only thing adding fuel but the computer limits how much can be compensated, plus I believe when you step on it it goes to close loop mode anyways taking numbers from a set value, been awhile since I messed with prom burning. For now I would jack up you fuel pressure and see if that helps but you really should get the proper injectors or get your prom reprogrammed.

 

Until you can get the 24# injectors,,, I'd put the 305 chip in it if you still have it and bump the fuel pressure to around 48lb. At least the injector constant and injectors will match up,,, it'll still probably be lean in the upper RPM range,,,, but it won't be near as lean as it is now during close loop and "cruise" conditions.

 

Dont do a job half A$$. Go get some new injectors.

 

Well, I had boughten a new Holley AFPR but it ended up leaking so I'm running the stock one, with the stock fuel pump. The best fuel pressure I could get with the AFPR was 42lbs. I think I'll start with getting injectors, working AFPR, and Walbro pump(next year, spent too much on the motor this year). Just wanted to see if there is anything that I could "rig" up for the time being so it runs like it does in the initial first 4 minutes, because despite everything it runs hard during that time.....