Help setting up FAST

[Razor]

Ok, I'm in the process of helping out a friend that is experiencing a no start condition.

The vehicle in question is a SBC 421 ci, .700 roller, ATI D1 blower, 83 lb injectors, etc... The FAST is a bank to bank.

The plugs when pulled were all black on all cylinders. After replacing plugs, the car would sputter after started. And now doesnt start. Pulled all the plugs and theyre saturated with gasoline. Upon inspection of the distibutor, found the module to be rotted due to a hole on top of the cap, and water that had seeped in. Got a new MSD distributor, swapped shafts since the reluctor was special on it, dropped it in, now it wont start. It makes sounds like its missing, pops, has smoke coming from the back while cranking, and plugs are drenched in gas.

Pulled the plugs cleaned them with brake cleaner, aired the cylinders out by spinning the motor over, plugs back in.. same.

So this is my question, which I cant find anywhere.

One, the setup on the crank trigger is suppossed to be .050 thou. It was 110 thou. So I corrected that. And its at 50 BTDC in relation to the timing mark on the balancer being at zero. Tho according to him, was suppossed to be set up at 70 per the original guy who set it up.

So heres my quagmire. the distributor. The reluctor appears to be at 25 degrees from the the rotor tip. It was setup like this. When you set the distributor, is it done with the motor on "0" and then the tip pointing torwards cylinder one? Or put the balancer on 50 and then point the rotor to 1.. I dont get exactly how to setup the distributor. Ive tried moving it around, an no change in the way it responds. Tried at 50, at zero, in between, etc.

On the dash display, the timing was set at 56 degrees. The MAP sensor is reading 1.5volts so its good. While trying to start it will drop voltage a little so its working. TPS is working. RPM is working. i'm missing something..cant put my finger on the problem. I dont know if the MSD 6a box could be bad? There is spark, so coil should be ok.

Lastly, if I unhook the pickup connector from the distributor, the plugs are still firing. Is this normal. Appears the crank trigger is doing this.

I have spark, tons of fuel, doesnt start. trying to figure out.

Any help would be appreciated. Thanks guys, sorry for the lengthy post, just trying to give some background.

Lastly, fuel pressure is set at 58 lbs. Its not boost/vacuum referenced.. yeah yeah I know. This was the way it was setup.

Ohh boy ..

 

[bobc455]

Have you put a timing light on it? Where is the actual timing?

Why do you have timing set at 56 degrees?

-Bob Cunningham

 

[NoSlix]

If this is a bank to bank unit and you've got a crank trigger, all you should care about on the distributor is if the rotor is pointed at #1 when the motor is at tdc. If it were a sequential unit and you were using the cam sync signal out of the distributor, then yes we'd have to worry about rotor phasing. But with the ct, it's signaling the FAST where tdc of each cylinder is. You're just using the distributor to distribute the spark, not signal anything. You don't even need the pickup on the distributor connected to anything with B2B. So here's how I set em up:

1. Turn the motor over until it's at 50 degrees on the timing pointer.
2. Set the crank trigger up so that it's on top of one of the magnets .
3. Set the air gap on the sensor to .060.
4. Set your crank offset to 50.
5. Turn the motor to TDC.
6. Turn your distributor body until the rotor points at 1 when the motors at tdc.

The car should start. Then increase the air gap on the ct sensor .005 at a time until the car won't start. Narrow the gap .005 and you have the optimum air gap. This is usually in the neighborhood of .070 to .075 with the FAST as opposed to the .050 that MSD tells you. Hope this helps.

 

[Razor]

bobc455.. maybe hookup the light and confirm it flashes when the balancer is at TDC? I'm use to using lights on motors that are running. I didnt set the timing at 56 degrees. I'm just reading info off of the dashboard display. Actually was told it was suppossed to have been setup at 70 degrees.

Shane, car is setup as you describe, and wont start. Hence my post. I was wondering if I was doing something wrong. Yes I put the car on TDC and put the center of the rotor on cylinder one.. No fires. The air gap was .110 and I dropped it to .050 in hopes that was the problem. Plugs are fouled big time in a hurry. You crank it 4-5 times and makes a want to start sound.. but doesnt.

Maybe time to do a compression test? Coil is firing, whether its firing at the rite sequence..dunno.

What is the mag pickup in the distributor do? I would assume even if I was off 5-10 degree it would still start. Am almost out of ideas..

 

[Craig Smith]

Shane, your instructions would lead to the rotor being phased at TDC if I read them correctly. I would not recommend doing this. After setting the crank trigger at 50, roll the motor to wherever you run your timing at peak torque (25 degrees or so, not TDC) and line the rotor up there. Phasing the rotor at TDC would present a big opportunity for crossfire in the cap.

I would disconnect the injector harness and verify that the timing light matches what the FAST tells you the timing should be. This will prevent you from blacking the plugs out while you make sure all is well with the ignition timing.

I agree with all the other advice posted here. The crank trigger is what give the ECU its RPM signal here, and the B2B system does not require a cam sensor input, which it sounds like the distributor has been modified to provide by offsetting the reluctor and the rotor tip. You may leave the sensor in the distributor disconnected as it serves no purpose in this application.

I'm guessing that this problem is mostly related to getting the timing set up correctly. Keep us posted and good luck!

 

[NoSlix]

Oops. You're right, Craig. It's been so long since I've done one that I forgot about that.