Aloha all,

Wondering for those who may have the classic FAST EFI. Looking for advice on you may have done your initial timing for your engines. Some posts I have found state set the initial timing at zero, then found another post that states to place timing about 30 degrees before TDC.

The installation manual states: “The EZ-EFI™ system does not control ignition timing. Along with air/fuel ratio, timing also plays a large role in how an engine runs. Be sure your ignition system has an appropriate timing curve. Don’t forget to consider factors like mechanical and vacuum advance. For example, if the engine has a surging idle, it might want a richer (lower number) Idle Air/Fuel target. Or it might want less timing. Or, the cause could be oscillating timing caused by overly light springs in the distributor. Another example would be if idle speed often dips and threatens to stall. The engine may prefer a different Idle Air/Fuel target. Or, it could be that more base timing or more vacuum advance would give the engine a more robust idle. These examples happen to be about idle, but of course, timing affects all modes of engine operation –tip-in, acceleration, cruise, etc. The point is that air/fuel ratio and timing both need to be optimized for the engine to run at its best.”

What did you guys do on your EFI system? There doesn’t seem to be a lot of information for the classic FAST system, most I found is for the 2.0, thanks for any input.

 

You set timing and curve just as you would with a carburetor. But as with a carb....the timing needs to be optimized and set before any tuning can begin with the EFI system.
Personally.....I do not like these EFI units with no timing control for a lot of reasons but mainly because a real time fuel system needs real time timing to boot......and the A/F and Timing work together in any car built after 1990......this is not a new thing.......leaving the distributor mechanical defeats the whole purpose of having an EFI in the first place....just tune the carb it had on it. Only real benefit is being able to let it sit and fire back up after a year......which is a big benefit.

So here is why I do not like them......my friend and I picked up a ratty 71' LeMans GTO "Judge" clone with a real bona fide 455HO in it, a blown rearend....and a FiTech EFI unit that the previous owner said ran like ****.......it had an ancient Edelbrock SP2P intake( which you could not go through history and pick a shittier intake to put on a 455.....not possible....even a 2bbl intake flows more air.).....of course it had a divider. The distributor was a unknown HEI.....my friend asked me to get it running and tuned. We got it fired up and it ran like flat dogshit......the EFI controller would not tune out a rich issue down low....erratic idle....etc.....but could not drive it until the rearend was setup.
We bought the rearend **** and I set up a 3.55 Locker for it.....and attempted to drive it.....it ran poorly, no power....etc......
I set total timing to 38 degrees (big bore Po-nac) and disabled Vac Advance as the vacuum was too erratic anyway at that point to have it connected. Of course it responded....and we could now drive the car down the road.....but way too fat at idle jumping to a lean pop condition on any load requirement. I went in to the FiTec controller and tried to tune it out and no bueno......nothing I did would make the idle lean out.......
I slept on it and it occurred to me to heed my own advice (which eludes me some days).....and get rid of the **** small runner oil embargo 1977 BS intake and find an old Torker single plane. New units were like $600 so no way.....Marketplace had one potential candidate.....and I bought it....two guys even delivered it from out in the country (Between the two guys they had about seven teeth....were driving an 86' Nissan Hardbody mini truck with at least two different colors of primer....the purchase was worth it for these two throwbacks to show up!).
I blasted it, squared the mating faces, put heli-coils in the carb pad and painted it blue......on it went. Now here is the part you have been waiting for......at startup....with no other changes.....the idle jumped to 16:1 and setting it to 14.0 made it idle nice.....but it would barely free rev.....I added 45% more fuel in the FiTec controller to tune out the lean......it would boil the hides and make kids cry for Mom after that.....but trying to use the vac advance was futile....it hated it....I also needed more initial timing (I was at 13) and could not do that without a whole distributor revamp......if it had timing control, push four buttons and done. You can get the distributor sorted....but now you spent $1000+ dollars on an EFI and still have to do the distributor.....which 75% of people swear they know how to do and really have no clue.
Point is that no one should ever use these EFI units without knowing a few things first:
-These things DO NOT like dual plane intakes and that is what everybody has and what every car in the world had in the carb days.......and no matter what I say....folks just bolt them on because the old "Well Holley said it was fine...." scenario.....and I simply will not work on them as it is poison....the customer will not agree that it needs a single plane intake, and if you cannot tune it with the dual plane then you do not know what you are doing. The other thing about these dual plane intakes is that 75% of them have the heat riser port still functioning.....so after two hours of driving around town the engine runs sluggish and idle response is **** because the air/fuel is so hot going into the engine......this isn't a problem with a carb as the the atomizing fuel supercools and counter acts the hot intake.....so why would anyone in their right mind pull an intake to block this and not switch it out? Because the seven pages on Facebook and the 25 year old at FAST told you it has nothing to do with it. Absolute poison.

So.....to the OP.....what are you working on?

Jebby

 

Initial timing is not related to what fuel system you have,. It is more a function of your compression and cam. For a stock engine, first look at a service manual to see what the initial timing should be. Usually you can advance a few degrees beyond that for better driveability. Be sure when setting initial timing you do this with the vacuum advance hose off and plugged.

Once you get the timing right, the FAST system should self tune to the desired AFR.

 

I guess Jebby sure doesn't like stand alone EFI systems.
That's OK. I run one anyway. And I like it.
Bottom line here is your question about ignition timing.
Your EFI system really has little to do with your timing settings. As mentioned above, your compression and cam specifications will dictate how to set up your timing curve.

 

Here is a thread that talks about modifying an HEI distributor to be controlled by a FAST system.

 

Wow Jebbysan, 4-vettes, & RocketJSquirrel great input, lots of information. Here are some more specs on my engine yet your posts did give me many great things to think about.

As most, I bought a C3 project in boxes, so many items were there just not put together and nothing in this car is original. Technically, it’s a 1968 C3, that looks like a 72 and the parts are more like from thar Johnny Cash song “One piece at a time”. (But I love it)

The engine is a Dart 4-bolt main 415Cu block (3.875 stroker, 550 - 580 hp range – gkull), Comp Cams, Xtreme Energy 242/248 Hydraulic Roller Cam and Lifters, Forged Eagle crank, Weiand Team G Intake Manifold, Brodix heads, FAST EFI - Self Tuning EZ-EFI (Classic Ver), MSD Ignition 6AL module, and an MSD Pro Billet distributor PN 8360.

I was told it was fired up on a carb initially, yet that carb didn’t come with the car. I installed the EFI system and finally fired up the engine a few weeks ago and it sounded great. I started thinking, I should check the initial timing before putting some revs behind it.

I’m in no hurry as I only get to work on it for a few hours once a week and I have a motive brake bleeder on order to double check the Wilwood brakes. With winter approaching, I will finish the brakes and work on building interior panels to get it ready to drive next summer. (I have the dash, carpet, seats & center console but nothing past the seats)

My C3 won’t be a showroom or car show winner, I just want it to be a street machine.


As always thanks for all the input.
V/r,
Karp