Here are my 2 questions - the rest is what I've done so far.

1. I sent my used box into FAST HQ before I installed it to get it converted from trigger ignition to TFI. Do they check everything else out for the $50, or do they just pop it open, work their magic on the ignition circuit and close it back up? I don't know.

2. Besides everything I've listed below, is there something I'm missing? Could I have fried the injector drivers?

I've got it narrowed down to the injectors not firing at all. But why? This is an old FAST B2B w/ TFI. I had it converted by FAST from a trigger to TFI ignition.

- Relays are functional. C-Com comes up and jives with the computer, no sweat.
- Both the 3A and 30A harness fuses are good
- 19# injectors (for now), configured for 1.0ms opening time
- 3 Bar MAP, configured for 3 Bar in software, tested and works so far (97 kPa @ atmosphere, ~43 kPa at 15" vacuum, aka 1/2 atmosphere: ok)
- 40# of fuel pressure
- Spark is good, firing order good, timing set at 10* BTDC with SPOUT out.
- During all attempts to start, I've had either a strong battery or a jumper car hooked to the battery

- The kicker is that it's in a BB Chrysler, which spins the distributor CCW and not CW. This doesn't seem to matter, because I tested the distributor with everything plugged in and turned on - forward and backward with a hand-held drill register the same RPM. Drill spins to 1000RPM; FAST says ~1950 both ways, so that's believable.

- When cranking, the VE table "bubble" moves around predictably.

- Yesterday, while testing the distributor by hand, (again, with everything plugged in), every time I touched it I heard the fuel pump whirring and the coil clicking. I put my ear to a screwdriver touching the injectors and heard no ticking.

- After many minutes of cranking, the manifold does not smell like gas at all.

- When a cup of gas is poured down the TB, I get 3 or 4 relatively clean revolutions before it sputters and dies.

- I've forced my VE table to 60, 80, 100, as well as jacked the cranking pulsewidth vs. coolant map to the roof, all with the same results.

I am pulling my hair out here. Help!!

 

Re: FAST B2B trouble - please help (long)

What is your TPS reading during cranking? If it's over 80, the injectors won't fire.

Set crank to run mode RPM to 300 RPM.

Make sure FAST is reading RPM during cranking.

Verify +12V on the red wires of injectors.

Your injector drivers are fine, guaranteed.

 

Re: FAST B2B trouble - please help (long)

Woah, awesome, thank you. Great info.

TPS value is 26 closed - but I did not know that about the "above 80" rule. I'll be more careful when feathering the throttle. (the TPS works too....floored = 90+)

I will make sure I have the crank to run RPM at 300.

I believe it's reading RPM during cranking - the bubble moves down and to the right a bit, and it displays 150RPM in the box at the bottom.

I will verify +12 at the injectors. (I didn't check that - sometimes it's hard to think of the easy stuff when you're really pissed, hahaha)

 

Re: FAST B2B trouble - please help (long)

double check you grounds

 

Re: FAST B2B trouble - please help (long)

Make sure the injector wiring is getting 12 volts not just with key on, but also while cranking. some circuits go dead in crank mode, depending how you sourced your relays.

 

Re: FAST B2B trouble - please help (long)

Yea. on the Mopar that would be exactly right ( going dead on crank mode if not wired right)....


Also you meantioned it showed 150rpm when you was cranking? that sounds like a problem. If the crank to run is set to 300rpm, doesnt the engine have to crank over atleast that rpm before it ingauges any fuel,ect,ect.

Jess

 

Re: FAST B2B trouble - please help (long)

+2! I am an idiot. And, a freaking amateur. I missed the ground for - get this - the injector power relay.

But, my crank-to-run was set at 200 or something, so I set that back to 300 (thanks for that tip, Craig).

Futzed with it for 10 minutes and thumped the neighborhood pretty good with my open "zoomie" turbo headers, hahaha. It now starts right up and has a very stable idle. Yeah!! Waiting on brake lines and downpipes so I can tweak the rest of the map!