I just pulled my 383 out of my 89 IROC and put in my 91...it ran alright in the 89 but it barely runs at all in the 91. It pops out of the exhaust and intake??? It also won't idle. I have to keep giving it gas to make it run. Its a 383 with Dart Iron Eagle heads, mini ram intake, 22lb injectors, Comp Cam(510 540 lift and 230 244 duration and 112 lobe sep.). It still has the stock 305 computer chip but I don't think it would cause it to run this bad??? It hasnt' thrown any service engine codes. Its also running really rich. The only thing I changed when I pulled the engine and put in my car was the Knock Sensor and I had to have my MAP sensor off my 305. I don't have a clue where to start. Anyone???
Thanks,
Adam

 

Does the car search for an idle? If so look into it being the O2 sensor.

Also, you are trying to run a 383 TPI on a 91 305 Speed Density chip... It will not work until you get the calibrations in the chip correct. Burn one yourself or have one done for yourself.

Its a start.

 

The MAF set up in the '89 will compensate better for the extra 33 cubes with stock calibrations.
Check the fuel pressure?
Try a MAP for a 350?
Any vacuum leaks, hoses off?cracked plastic lines?

 

383 engines should have 24 - 26 pph injectors. I'd be afraid to run that big a cam with 22 pph injectors on a 383. 305 computer chip is set for 19 pph injectors. 91 Knock sensors go to the ECM whereas 88 KS goes to a module then to the ECM, AFAIK. If you have time to screw with it, learn how to and burn one yourself. If not, get someone to do it for you. Try www.fasterproms.com for a true custom chip. They will send you one right away and you can borrow the Diacom software and get a laptop from a friend and send them the readings. After that, they burn it once more, you take readings and they burn it another time and so on till it is right on. Usually takes 3 burns and it will be on the money. Total turnaround time is less than 3 weeks and you will have your car to drive usually the first day the chip arrives. After all is said and done, send them a check for $500. In future, all mods that require a reburn will cost you $150.

 

what should my fuel pressure be set at???
Adam