Where is a good place to start with fuel pressure on my 350? I have the accel 24lb injectors and a TPIS afpr. The afpr instructions recommended 47 or 48lbs (something like that). Assuming this was for stock injectors.

I have already ordered the PROM burner and additional chips which should be here today...just in case the recommendation to make some adjustments to the PROM come up.

Your help is always appreciated.


Marty

 

Are you running 24lb or 26lb injectors? (Your sig says 26lb). Whats your compression ratio? What are you exact cam specs?Running high fuel pressure on stock injectors (22lb) on a combo that needs 24lb's, will make you run rich at idle and lean on the top end. I would recommend running 38-40lbs of fuel pressure (yes, de-tune your fuel pressure) if you are using 24lb injectors. That way you wont run so fat at idle and so lean on the big end. Then do all of your chip tuning from there!

 

All injectors are not created equal. You need to look at the data sheet. It will give you the open to close time intervals (dwell time) based on inlet pressure. In other words, once the injector has been fired, the amount of time required for it to reseal. You can compensate for the amount of fuel on each cycle by adjusting fuel pressure or changing the on/off cycle time in the prom. As 1Bad says, if engine appears to be running rich at idle, reduce fuel pressure until you get you prom burner. You may want to get a UV light to erase your proms (electricity is cheaper than chips). You will probably burn quite a few to get it right. Begin by making minimal changes at first and document what you've done each time.