Reco on injection and ignition


My Fortus (347 SBF in a Lotus Esprit) project is making progress. I have the engine/transaxle mounts fabricated and the drivetrain is essentially mounted. Now comes the tough part - axle shafts, hooking up the ancillaries, oiling, cooling mods, etc. etc....

I have a basic Holley double pumper on there for fueling, and a basic ignition system with a regular HEI electronic dizzy and integrated coil (see pic) and vacuum advance.

I would like to add direct port injection ("8 stack"?) system to replace the Holley. What I'm hoping to find is super duper simple and dead reliable. I've looked at the FAST EZ 2.0 injection management system with a decent looking manifold and throttles/butterflies. Is there a better/easier system? What injectors are recommended for a 347?

I would also like to add a more sophisticated ignition system. Similarly, something simple and dead reliable is desirable. Multi-coil is fine, with the ability to change timing and advance curves easily....with a selector or dials or a laptop. Would be nice to lose the big tall dizzy if possible.

Any recommendations appreciated. Thanks.


It won't look as fancy as the 8-Stack systems, but I'm planning of using a FiTech EFI system on my build. Single unit EFI Carb with built in ECU and most of the sensors. Self mapping. Most will do basic timing control with the correct distributor, either a locked out MSD or a TSP Pro Billet small cap. I’m aiming for simple, reliable systems with minimal tuning. Hence liking a self tuning system, and avoiding complex multi throttle body linkages, separate ECUs etc.

Forgot to add: the small cap is quite a bit smaller than the HEI dizzys which should hopefully help you.
If you want to go 8 stack, you really can't beat the design and reliability built into the Borla systems (Roush uses it....was TWM). There is a vacuum plenum built into the underside of the manifold (hidden) so the GM MAP sensor samples all 8 throttle bodies. There is an Idle Air Control system also built-in using a dead reliable GM stepper IAC motor. The throttle bodies are mechanically connected using flex couplings which help eliminate any binding (and wear) between throttle plates from the heat expansion/contraction of all the components. They're easy to sync, then forget.

Speaking of vacuum, you need at least 10" of vacuum at idle for these EZ-EFI systems to work, they don't always tell you that. Throttle bodies can flow a lot of air, instantly, so you need to have a more capable ECU that can handle the instantaneous changes in airflow/load, and a wilder cam.

Now, I know they (FAST/Borla) try to push the EZ-EFI 2.0 with these systems, but I don't recommend doing so (I had a good long talk with them about this at SEMA 2016...). If you do, you will eventually end up spending more money to get what you should have in the first place....that being the more advanced ECUs such as FAST XFI Sportsman or the XFI 2.0. The EZ-EFI systems hook you then you realize you need more control once you better understand EFI and what your motor needs. Now, don't get me wrong, I've had great success with EZ-EFI 1.0 on my Borla 8 stack paired with a programmable MSD ignition box, and it's ran great on the track, but you really DO need to have better control of your ignition system (EZ-EFI controls fuel only!) vs trying to control it with a standalone ignition box or god forbid, timing advance springs.

You can remove the distributor, place a cam sensor in place of, or leave it in and lock it at a pre-determined BTDC setting (usually 50 deg), your choice. If you see yourself eventually going to individual coils (COP), individual cylinder tuning, etc, then go XFI 2.0. Do it right and dispel some of those myths you hear about stack injection.

Injectors....what is your planned HP number? All the above mentioned systems will support 550 hp and beyond. You can calculate your injector needs off that or when you place the order with Borla.

You didn't mention anything about exhaust system....simply put, crap in...crap out. If your exhaust system has leaks, the O2 sensor can't do it's job and won't know what the difference is between lean cylinder and air leaking in and around a collector, joint, gaskets, so you'll end up with a turd. A little reversion from a megaphone/short pipe is OK and can be tuned out in that rpm/load spot....or not. You have control now!

Bottom line....don't take shortcuts, spend the money to do it right, intake to exhaust.
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Randy V

Staff member
Lifetime Supporter
We just threw in the towl on an EZ-EFI Fast 2.0 system.
It was flakey at best and many times would come up with communication errors and just shut off. The tech support line was absolutely NO help whatsoever, insisting that the problem was noise related etc etc... I re-wired the unit to hot/grounds precisely the way they recommended on 3 different occassions - none of which produced any different results.
The system we bought was complete with their fuel system and distributor. They refuse to replace the ECU (it is still within warranty) and at this point - even if they DO agree to replace the ECU, the customer has lost so much money ($3500 in parts alone) and confidence in the system that we just removed it and installed a Holley carburetor and aftermarket distributor.
My thought is - if the system is so doggoned "touchey" in terms of noise / RF interference - it has absolutely NO place in a car...
I would post pictures but unfortunately the website seems to be refusing uploads right now...
Suffice to say - this is a 6 figure street rod build and no expense has been spared in its creation.
Hey Randy,
Nice Rod....

Are you saying the Comm error is USB related (comm port?) or somewhere else in the system as in the harness and sensors? Did you inspect the 40 pin receptacle and plug? Turn off/disconnect sensors? I doubt it's an RF Noise or even an ECU issue.

Here's the thing, I always avoid using those "universal" harnesses mostly due to the need to hide and clean up the "technology" for a more period correct look. That said I build my own harnesses using proven 'mil-spec' aircraft wiring (unshielded Tefzel) and avoid any plastic corrugated shielding, clamps, or zip ties. I purchased the 40 pin ASM Plug and connectors from Mouser, and crimped my own using the required crimper.

I do recall a wiring/harness conversation at SEMA with FAST where it was briefly mentioned that the stock female connector can sometimes unseat itself inside the plug, thus will not fully seat with the male pin in the ECU. This would cause an error or give intermittent problems.

FWIW, I always treat these cars with the mindset that pulling off to the side of the road is not an option for me, so reliability, redundancy, and a backup, where it can be applied, is first and foremost. Think, aircraft systems reliability... I even use aircraft circuit breakers so I don't have to carry fuses. LOL

Cliff, I just realized that I may have hijacked this thread....feel free to remove the post and we can take it offline.
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Randy V

Staff member
Lifetime Supporter
Tom --
I think these posts are totally relevant to any EFI / Ignition recommendations.
We have another customer that has the FAST 1.0 system and it has been rock solid and a great performer with a pair of DCOE look Stack Injectors on a small block Ford.

The last wiring change I made on this car was a twisted pair home-run for both ground and 12v from the battery in the trunk - which we also replaced because the original battery was only 12.5v and FAST Tech support said we did not have enough juice ((BS)). Being familiar with aircraft systems, you know that the only way to get better than twisted-pair is Shielded Twisted Pair.
The big plug on the ECU had a couple of females that were not totally seated. One was not used, the other was for the high speed fan.
I programmed the system with some pretty basic settings for the displacement and found that it was giving waaaaaay too much fuel for a prime squirt and cold run - so I backed both of those off to -3... Much better starting after I had to replace the spark plugs due to being flooded too many times and was not sure of them even after torching them...
Started and ran good until about the time it went into closed loop mode and then it would die just like you switched off the key. Odd... plugged in the hand held display to watch it. It still died about the same time - no more than 2 minutes into the run it would die. The Hand Held flashed "Comm Error" and then went blank.
From there we went through umpteen different wiring routes, then finally re-wiring. I even tried shielding the wires with HVAC aluminum tape - no difference.
Let me tell you, working inside the console and under the hood of this car is not a lot better than laying on your back under the dash of a GT... Very little space.

In my opinion the ECU is hosed. FAST is not convinced.
I am convinced that given the preponderance of similar evidence I have found on dozens of forums all exhibiting similar issues that the FAST 2.0 was rushed to the market and is buggy..
We have even talked with Brian Macy about this system.
The carb works really well and sure simplifies the electrical system of this car...
I am reading really good reports about the FI-Tech unit... I may pick one up for the next EFI car..

- your wiring should be fine. No need for shielded wiring (maybe for a crank trigger), but it should not be the cause of shutdown at the Closed Loop trigger point...
- going into closed loop within 2 minutes of a cold start, or warm start (usually > 140 deg H2O)?
- running a datalogger at the highest hertz setting so you can observe what happens at the instant closed loop is triggered would most likely give you an answer as to the path the engine took before shutdown. The Sportsman or XFI 2.0 have built-in dataloggers, and so do other advanced ECUs. A standalone O2 sensor will also data log, and I have one on the other collector to "compare notes" during the initial tune.
- Cold Crank/Afterstart fuel settings....usually set at the factory on the conservative, Rich side initially and it improves from there. I hear the EZ 2.0 gives you more cold start (choke) adjustments, which appears you made a positive (negative) change to.
- Comm Error....what path was the O2 sensor taking before "Comm Error"?
- Going back to Carb = Defeated! C'mon you're an IT guy, you can figure it out! It's not Rocket Science, but it's not Model Rocketry either, it's somewhere in between. ;-)
- If you're sure about the ECU, then send it in for warranty(?) repair, give it a good bill of health, then sell it.

Honestly, at this point, it's all irrelevant (you don't need to answer the above questions), since you've pulled the system off already. This is more of a posting to help others decide, lessons learned, etc. As stated earlier, when it comes to a GT-40, stay away from standalone, self-learning systems that only control fuel, unless you know what you're doing. I run XFI Sportsman, and so far I'm happy with the control it gives me for this nostalgic car/motor combo. If I had a more sophisticated car/motor, then I'd move to a COP setup, crank trigger, cam sensor, etc., and XFI 2.0 or another ECU. I have over 3000 miles on mine (road & track) since last August.

I think we scared off Cliff.....he's probably shopping for Webers now.