How fast does your tbi vehicle start?

[brian617]

Distributor Rotation Pulse I believe. Like cam sensor counts?

[PlayingWithTBI]

Distributor Rotation Pulse I believe. Like cam sensor counts?

IIRC Distributor Reference Pulses (from the ICM to the ECM). If it helps, my 88 C1500 5.7L cranks ~2 seconds when cold and almost immediately when warm with the 7747 in it. It's still the same with the EBL Flash-II.

I'm curious what you find to change that length of cranking although, I kinda agree as mentioned earlier, I like it delayed some so oil pressure can build up before firing.

[brian617]

Yep, that, Reference Pulse, dont know where rotation came from lol.

[tayto]

i found even increasing the VE in the crank areas helped with better start ups. found this out by accident when i got carried away smoothing the VE table and discovered the car took longer to start. the other thing is increasing base timing (ex: 10* vs 0*) at the distributor. this will also need to be updated in the calibration. i also am a big fan of the newer pg260 gear reduction starters used on the 96+ gmt400 trucks.

[joegreen]

All interesting observations. Thanks everyone. Today under the choke table for afr vs temperature when cranking i decreased the afr and it started cold in what sounded like 4 engine revolutions. Which i think is better but its hard to tell because it was warmer out today than usual.

[stew86MCSS396]

Don't know if I missed it reading from the beginning but first inclination would be to ensure the fuel pump relay is operating as it should and fuel pump is not solely running off the oil pressure switch.

[joegreen]

Don't know if I missed it reading from the beginning but first inclination would be to ensure the fuel pump relay is operating as it should and fuel pump is not solely running off the oil pressure switch.

Thanks. Fuel pump can be heard running when key is turned on.

[PlayingWithTBI]

All interesting observations. Thanks everyone. Today under the choke table for afr vs temperature when cranking i decreased the afr and it started cold in what sounded like 4 engine revolutions. Which i think is better but its hard to tell because it was warmer out today than usual.

I'm curious, what values do you have now? Here's what mine looks like

[joegreen]

I'm curious, what values do you have now? Here's what mine looks like

Its interesting your is so much different. Maybe we are looking at different tables. Mine is cranking afr but yours just says afr? Maybe they are the same.

Capturewer.PNG

[PlayingWithTBI]

maybe because mine is from the EBL Flash-II instead of your 7747?