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FCC2 and pwm setting

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Quote from Austin DeHaas on January 12, 2020, 9:14 pm
Quote from whollsee on November 13, 2019, 5:02 am
Quote from Austin DeHaas on November 13, 2019, 12:03 am
Quote from whollsee on November 7, 2019, 5:18 pm
Quote from 1972Mach1 on September 23, 2019, 1:11 pm

Just got off the phone with Hyperfuel after I emailed them 1/2 hour ago (imagine that, a company that promptly gets back to you!), and he told me I need to have the PWM set at the 74.5 that comes from the factory.  Setting the PWM at 40 is for the original FCC, but the FCC2 requires 100% pump run time.  Neither one of us is positive that this is the issue as it should have affected it at more rpm/throttle positions and not just low settings, but I'm going to try it anyway.  Hopefully that works.  But, anyway, good info for those with the FCC2 to keep your PWM set at factory spec of 74.5.

How is this working out for you now '72? Did it sort your issue?

I did wonder about that PWM setting at install/set-up. Instructions seemed to be referring to the original FCC. Fitech neglects to sufficiently update guides and tech info generally. Glad you got confirmation. I've flicked my setting back to 74.5 as I had the odd stall and/or threat of a stall when coasting to a stop and IAC steps were dropping slowly to zero. I'll wait and see if it helps.

Yes, the fcc2 should be at 74.5.  The information provided was for the original FCC.

Try disabling your DFCO to remedy the stalling problem when coming to a stop.  Raise enable temp to maximum, essentially disabling it.

Thanks Austin. Yes saw your DFCO recommendations elsewhere on forum. Will maybe get a chance to test proper this coming weekend.

So here’s a hypothetical for you...I have the GS 400 which apparently has a 43 psi reg due to the injectors and the FCC2 has a 58 psi reg. Could one swap the regs on the units thus having the fcc2 provide the preferred fuel pressure to the GS 400? The 58 psi reg now on the TB of course is disabled by the closed off return port there. Worth a crack or a big waste of time? I know you are not a huge fan of the sump pump units generally but humour me!



Not sure why I hadn't seen this post.  My apologies.  58psi will not hurt the unit.  You can try your theory, but not necessary.

No need to apologise. Yeah I’m more interested in driving it than playing with the moment anyway.

I have pretty much the same set-up on my 78 Bronco. Runs great until I have been on the road for 30 minutes or more and then take my foot of the gas and go below 10% throttle. Goes wildly rich then lean then stalls. My hyperfuel is tucked away in a corner of the engine bay and doesn't get air. I heard mention of heat soak as a major problem. Is that something I should just put a heat shield of some sort on? Would that fix it? Have had a series of issues with this fuel system, it seems.

Do not use 74.5 PWM on FCC2 it boils the fuel inside the cell and causes vapor lock. Drop it down to 40. This is the case at least with stock tune engine. I did reset my Fitech this May and got stalling issues ever since. I forgot to drop the PWM to 40. After dropping it back no issues.

1963 Imperial Crown 413 dual quad Fitech
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