players 91

Hey guys. I'm trying to get my 408 swap starting easier. Usually I have to make 3 to 4 attempts before it starts. When I spray a little gas through the throttle blade it will fire right up. Should increasing the cranking ve numbers give me a little more fuel while cranking, or am I missing the point of the function of this table?

tech@WS6store

iTrader: (2)

That is prob the easiest way to yes. If you still have an issue you can try working with the startup spark table also. Sometimes its due to not having enough volume at the rail at key on sometimes due to a bad fuel pump check valve.
Try the ve first and see what happens!

dw456post

Increase you prime time to about 6 seconds. Then turn the key to "on" for 3 seconds, then start. Maybe there is no residual pressure valve in the fuel pump and it takes a few seconds to get the fuel up to pressure. Normal prime is 2 seconds. Just a guess since you didn't post any details. If you have a big cam, or different MAF, or different TB, then it is probably in the tune somewhere else.

JoeNova

I usually have it dump fuel lots of fuel while cranking.
Every swap I've done, I've added 30% while cranking and they start up much faster. My Nova barely even bumps before its running.

players 91

Thanks for the reply guys. Some info on what I'm working on, it's a lq4 408 with a bar stage 3 turbo cam, 230 duration 600ish lift. 317 heads, and all the free mods I could find on these forums. Pocket ported the heads, ported tb. Tb and intake are truck pieces and it has 80 lb siemens injectors. 2 in tank aeromotive 340 fuel pumps, and 2 turbonetics 66mm turbos. 411 ecm, converted to 3 bar sd.I compared one of denmah 3 bar 6 liter files and copied over the spark, ve tables, and injector info.

JakeFusion

iTrader: (7)

You really shouldn't have to touch it. Even when I had a big cam in this car (8" of vacuum), it'd bump once and fire. But only after I chased my tail with falling pressure at the rail. Put a mechanical gauge on it and make sure that it's not bleeding off pressure as soon as you turn the key off. Otherwise, it's usually some tweaks to spark and airflow friction and decay before moving to cranking fueling...

Also, one thing to note - add fuel at the 100-105 400RPM cell in your VE table. That works too.

players 91

Well I just got a chance to put a Guage in my fpr. As soon as the computer stops the fuel pump the presure drops from 60 lbs to nothing. I don't seem to have any external fuel leaks. Where could the fuel be bleeding off?

tech@WS6store

iTrader: (2)

Either the fuel pump check valve, the fuel pressure reg, fuel hose in the tank from pump to module or around the fpr itself. the housing can have issues sometimes.