FAST Dual Sync Distributor with Accel DFI Gen 7

[Bobby Fazio]

Has anyone run the FAST distributor with Accel DFI computer? My car has been running rich as hell since that last test run. Have been trying to diagnose for over a week. Plugs are black. Checked timing and it is still firing at 34 advanced so that would rule out any cam or timing chain failure? Checked ignition box and coil and I have plenty of spark. Looked for vacuum leaks but didn't find any. I reloaded the saved tune back into the ECU to make sure something weird didn't happen in there. o2 sensor and wiring is still in place but since I run in open loop, there is no correction anyway. My TPS is still showing correct voltages. The injectors fire in sequential which requires the cam signal so the only other thing I can think of is the cam sensor failing on the Accel Dual Sync dizzy. My first accel dual sync broke on the dyno so that is why I think these things might be junk. The FAST unit looks to be built better so I want to switch and see if that fixes anything.

And this was supposed to be the low maintenance "fun" car...!

[Ed Wright]

Bobby, if your just using it for cam sync, (with a crank trigger) just unplug it to force it into batch fire mode off the crank trigger. If that doesn't fix it, then it won't be the dist.
Might check your coolat temps and manifold air temps showing on your laptop to eliminate a lot temp indication causing it to run rich. Unplug one of those temp sensors and they show -40 deg.

[buzzinhalfdozen]

What Ed said, also if you've got any logs try looking at your pulse width or pounds per hour and see if they increased, if it's the same it should eliminate sensor input as the issue, if they have then you have an input the ECU is responding to in a negative way. Have you made any fuel pressure changes? Again looking closely at your logs may give you your answer. Good luck. Joe

[Bobby Fazio]

I can't access any stored runs, I recorded each run and it says there are no stored runs which is also frustrating. My sensors seem to be showing accurate temperatures. I don't know anything about fuel settings or what they should be. Had it tuned by a pro and saved it to a file. I reloaded that to see if it would fix the problem but it didn't.

[buzzinhalfdozen]

Ok well it looks like you'll require some assistance from someone with Accel experience. I'll assume speed density tune? If so what's your MAP sensor reading (possible vacuum connection or restriction in hose) maybe take a look at that since it's a big input for fuel strategy and you're saying IAT ECT sensors read normally. Is your TPS zeroed ? A quick check for the MAP is see if it reads same as BARO sensor (should be close with engine not running). Best bet in my opinion is to get to your logs and retrieve them your issue will almost certainly show up. Good luck. Joe

[Sean Cour]

Bobby, have you looked at the fuel side of it? Regulator? Pressure seems to be where it's suppose to be? Even on the run?

[Bobby Fazio]

I have good fuel pressure about 38-39 lbs and when I take vacuum away from regulator no fuel comes out. I think the injectors are just staying open too long and I'm trying to figure out why. Also, does anyone know about what number the Map sensor should be reading?

[buzzinhalfdozen]

As i stated MAP should be same as BARO (assuming you have a BARO sensor) engine not running most MAP sensors read approx. 99-100 KPA. Engine running will vary quite a bit due to intake and cam design, I would expect around 45-65 KPA at idle decreasing as you rev engine to maybe 35-45 KPA. Off idle your vacuum will stabilize a bit and provide a better signal. WOT you'll likely see 90-100KPA essentially BARO pressure. Good luck. Joe BTW your baro reading may be higher or lower than I listed depending on your location ie in the mountains or at sea level.

[buzzinhalfdozen]

Bobby, you find anything?

[Bobby Fazio]

Not quite.. I am wondering if my ECU is having internal issues. Could you check out my other thread with the screenshots and let me know what you think? Thanks for your help.