Help with FAST XFI Startup

[mike67cam]

Well, after 3 years, I am finally trying to start my 67 Camaro but am having some problems. It will crank, start to catch/fire-up, but then just cranks some more. It is getting spark and fuel pressure is constant at 45 psi. The engine combo is as follows:

509 ci BBC
D1R Procharger
FAST XFI
1000 CFM Throttle body
FAST XFI Dual Sync Dist.
85 lb/hr Delphi Low Z injectors
Solid Roller .644/.644 264/[email protected] 114 Lobe Sep
Merlin Single Plane Intake (like Victor Jr.)
AFR 335 Heads

I have the timing set at 25 degrees in the cranking area of the table and have adjusted the cranking pulse width from 11.5 to 6 ms. The lower values, around 8, seemed closer. Below 8 seemed worse. Voltage is about 11.5 V while cranking. TPS position has been adjusted to 4%, max TPS for idle set at 5%. All initial setup parameters (engine size, 2 BAR MAP, injector size, etc.) have been set and rechecked.


Any input, advice, or startup file would be appreciated.

Thanks,
Mike

[camcojb]

Check your iac starting position, make sure it's open enough. Sounds like the throttle body may need the blade(s) opened up a bit. It's a guessing game at first, but most all tb's I've bought new needed to be opened up. Once you get it up and running you'll need to properly set the minimum tb setting; fully warmed up, turn off all idle timing compensation, set all the idle timing areas to whatever number you run for idle timing. Command a very low idle speed (this shuts the iac down), like 500 rpms and set the tb to your normal idle rpm, like say 850 rpms. This allows the tb to be at the proper setting to idle without using the iac, so you get full benefit of the iac and timing compensation. Remember to reset your tps and max tps for idle in config, and turn the idle timing compensation back on.

Jody

[mike67cam]

Thanks, Jody! I will give it a try. I was commanding the IAC full open but thought it may require more TB opening as well.

Is there a rule of thumb for ball parking the cranking pulse width?


Mike

[camcojb]

Thanks, Jody! I will give it a try. I was commanding the IAC full open but thought it may require more TB opening as well.

Is there a rule of thumb for ball parking the cranking pulse width?


Mike

not really, I usually start with the default setting and work from there. For me, a little too much seems to start better than too little.

Jody

[Fuelie Nova]

I tried to delete my post but cannot... I was curious about your voltage while cranking... sorry.
Tg

[mike67cam]

I just wanted to post a quick update. I opened up the blades as recommended and reset the TPS idle position. I got the car to fire and then run with some additional after start enrichment and more CTS enrichment.



Unfortunately, I noticed strange readings from the O2 when the car warmed up. The A/F was constant at 8.5:1, no matter what I did to the VE table. After some troubleshooting and a discussion with a tech at FAST, we determined the Wide Band circuit in the box is dead. I pulled it out and it is on its way to FAST for repair.


Once I get the ECU back I can finish tuning the idle and then work on drivability. I'm a little bummed about the ECU having an issue, but hearing the engine run after a three year project build got me over it pretty quick.

[camcojb]

I just wanted to post a quick update. I opened up the blades as recommended and reset the TPS idle position. I got the car to fire and then run with some additional after start enrichment and more CTS enrichment.



Unfortunately, I noticed strange readings from the O2 when the car warmed up. The A/F was constant at 8.5:1, no matter what I did to the VE table. After some troubleshooting and a discussion with a tech at FAST, we determined the Wide Band circuit in the box is dead. I pulled it out and it is on its way to FAST for repair.


Once I get the ECU back I can finish tuning the idle and then work on drivability. I'm a little bummed about the ECU having an issue, but hearing the engine run after a three year project build got me over it pretty quick.

progress is key, and you're making that. Congrats, and let us know how it's working when you get the ecu back.

Jody