I have a 350, Comp 260 cam, 193 truck heads, Performer TBI, ExtremeFI TB, and headers. I was running a 7747 and had it working ok but not great, engine was sensitive to air temperature and would knock when weather was hot - played with spark compensation vs cts table but never solved the problem. Had a Comp Cams plastic distributor gear fail (teeth stripped off) so I replaced the distributor, figured I'd upgrade to an 8746 at the same time (including adding an IAT sensor). Have an Ostrich with socket booster installed, tuning with Tunerpro. I'm also running 20 psi thru stock 55# injectors.

My problem now is that I can't get the engine to start. I have spark and fuel but best I can do is get a backfire thru the throttle body if I hold the throttle open while cranking. I get 6 degrees at the crank while cranking (with bypass connector connected, using timing light). I've tried dialing down the fuel while cranking since I figure it's way too rich, accomplished this by increasing values in cranking AFR vs. coolant table. Have also zeroed out choke adder fuel tables with no luck. Changing the BPW seems to have no visible effect during cranking.

I've read Grumpy's "Initial firings" and "Start Routine" from the PROM Tuning Guidebook and I tried to keep changes simple just to get things started.

Is any of my tuning from 7747 applicable? Lots of similarities and I know they are same ecu family. I also tried to use as much startup numbers from 7747 in the 8746 but still nothing. Getting the 7747 going the first time was painful for me - thanks to Craig for his help! I'm afraid I'm in the same boat again.

Any advice is much appreciated!

 

Oh yeah - started with ANLU bin.

 

Q: Had a Comp Cams plastic distributor gear fail (teeth stripped off) so I replaced the distributor,

double check placement of dizzy? 180 deg out? Are you getting DRP in logs?

 

Got it running!

Thanks for the reply Ronny - distributor was 180 out like you suggested. Rather embarrassed about that but happy to have wheels again. So far the 7747 fuel values work ok in the 8746.