FAST XFI, no start

[hemi8]

New engine, will not start. Cal installed tune.
I'm following factory service manual "Engine cranks but won't start", step-by-step.
- Verified injector test light is functional.
- Fuel injector test light plugged into fuel injector harness and it does not blink during cranking
- I have 12V at the pink/black wire coil connector terminal "P"
- Coil connector removed, injector light plugged in, key-on, applied/touched 12V to coil connector terminal "C" and got no injector light.
- Circuit 430 is fine, I did a continuity check from the coil connector to the ECM connector and its Ok.
- I checked the voltage at ECU connector B5 and get 4.51V with key-on, which is within spec.

So according to the factory manual the ECU injector driver circuit is bad, anyone else run into this problem with Casper's box and/or FAST XFI?

Mike

 

[boostjunkie]

Does it fire and stall ?

 

[hemi8]

No, its trying to start but no, it won't start and then stall, just cranks.

Mike

 

[Pronto]

How about the lights on the Caspers box?

 

[hemi8]

No, will not fire.....no injector so no gas.

 

[boostjunkie]

there's two windows in the crank sensor if you have it installed in the wrong window it will not fire it needs to be installed in the first window farthest away from the plug of the sensor

 

[hemi8]

How about the lights on the Caspers box?

Yes, standby is on, 12v when cranking.

Mike

 

[hemi8]

there's two windows in the crank sensor if you have it installed in the wrong window it will not fire it needs to be installed in the first window farthest away from the plug of the sensor

Its installed correctly, plugged in and the gap is perfect.
Mike

 

[TurboBob]

if the injector lights on the fast are blinking, and you are not getting fuel, then find a stock ECM, put in whatever chip you can find for large injectors, and see if it will fire the engine.

this presumes that the FAST is getting proper sensor signals, so that it can deliver a reasonable pulse. But you said you had Cal looking at this stuff so I would presume the FAST stuff is verified

 

[hemi8]

I'm pulling out FAST and the Casper's box and sending it Cal, something is screwed in one or both of those boxes.

Mike

 

[TurboBob]

it seems possible. post back what you find. try the stock ECM trick, just as a point of data.

B

 

[hemi8]

it seems possible. post back what you find. try the stock ECM trick, just as a point of data.

B

Woluld like to try this but all I have is the stock computer. In order to try this I think I would need to have the drivers modified for large injectors and have a chip that does not use a MAF since I can't run one.

Mike

 

[Chuck Leeper]

It doesn't have to be drivable, just see if it fires up.

 

[TurboBob]

idle and part throttle is ok with a stock ECM, you don't need a MAF to see if it will fire, but a chip set up for large injectors would be preferable

 

[hemi8]

So any TurboTweak chip for 120lb injectors would work ok for this test?

Mike

 

[TurboBob]

yes

 

[hemi8]

Tried it, no go, narrowed it down to this:
https://turbobuick.com/threads/stage-1-block-with-stock-front-cover.99747/#post-682135

Mike