I have a 383 with lt4 hot cam, 58 mm TB, Lingenfelter SR, edlebrock e-tec 200 heads, 36# injectors, AFPR set at 45 psi inital timing set to 10* and a custom chip. This setup has run fine before but after this last freshening up it is now a MESS.

It will not idle with the MAF plugged in and pulling air through it. I can plug it in and set it to the side and its fine. I replaced it and the same thing happens with the new one and also runs super rich. I have cleaned/checked the IAC I hav also adjusted the TPS to exactly .54V at idle. The engine will now idle at 1000-1200 RPM in park but dies as soon as it is in gear. With the MAF unplugged and the 2.8L MAF it will idle in park and in gear. Is it possible that I just replaced my bad MAF with another NEW but bad MAF from the part store?

any ideas? Also I have been considering swapping to a Fullthrottle MAFT pro and using the speed density feature.

Any help would be great.

 

You need a custom-burned chip for that combination, particularly the 36# injectors. Burning your own chips would be the best solution to a smooth-running engine and getting the most power and efficiency. I have a 355 with the LT4 HOT cam and have run 24# and 30# injectors with no problem using the MAF setup.

 

I forgot to mention that mod. It has been done and the engine ran great prior to the last tear down to freshen it up. I have even used a random MAF I had lying around for a 2.8L wagon and it worked ok until about 1/2 throttle then it went RICH. I am guessing because of the smaller diameter resulted in a high gm/sec reading.