ok guys... i have NO clue about the prom burning and computer programming stuff, although i understand what it is. how to do it or what i even need are what i don't understand.

a long story short, i just rebuilt my engine (5.7 SD TPI) and although it seems to run good, it can't be up to par with the changes i made to the engine. in the rebuild evolution i put in an LT4 hotcam w/1.6 rockers (about .525 lift) and about a 2k stall converter. still have the stock 22# injectors in it. fuel pressure is set about 42, timing i don't remember. between 8 and 12, i think. i took the car to a friend of mine who put in on his scanner or whatever (i left the car with him) and he said it was running fine, except lean at idle. at least for now, i would like to get the engine healthy, but performance can come later, although now would be nice, too. anyhow, should i just give someone my gouge and have a prom burned, or go for the programming stuff? i don't even know if my computer is "reprogramable" or only able to swap proms. i don't want to get in to the multiple prom thing, i'd rather go with something that will last me long term. another negative for me is that i don't know how to reprogram and don't know what to look for or program to (make changes). the car is a 91 Z, 5.7 TPI. i believe the ecm is a 730

i've put about 175 miles on the new motor running around town, but do not want to take it long distance because i'm concerned about fouling up the engine because something ain't right. as i said, it seems to run well, but what do i know?

anyhow, i'd appreciate some advice, help, even a few laughs i guess. i want to make the engine run right and the best it can, so hopefully you all can help me in one way or another. or tell me to take the car to someone else who knows what they're doing... thanks.

KAM

 

Yes, you have a 730 ECM. I can't tell you how to tune for that engine combination, but I can show you how I tuned my 1994 Suburban TPI conversion. Since my engine is a stock TBI engine, I basically only had to adjust the TPI spark tables (lower spark advance) and I had to add some fuel to the idle and mid-range as well. IMO - it is not hard to literally make changes (i.e. datalog, read your stock chip, make changes to the binary file, and burn a new flash chip). Learning how to tune is the hard part.

Click here to see how I did it.

All the hardware and software I show on my webpage will work for you.

The first thing you should do is set your physical base timing (with the EST connector unplugged) to 6* BTDC. Your stock chip is set to 6* and your physical should match. Then if you need more timing, add it in the spark tables. You should also set your fuel pressure to 43.5 psi with no vacuum.

Best of luck. I almost forgot, don't forget to search the DIY-PROM section at TGO. This is where I learned how to everything that you are asking. Ed