FI Tech "Go EFI 4" Self Tuning Throttle Body Injection Install Thread

Discussion in 'High Tech for Old Iron' started by real82it, Nov 2, 2015.

  1. Ken Warner

    Ken Warner Stand-up Philosopher

    Well, if I were to venture a couple of things to try.

    1. make sure you have full 12+ volts to the ignition at all times. As mentioned before you may have an ignition problem you assume is fuel related. Also depending on what version of Pertronix it may be causing some grief. There was a version that tried to do multi spark at low RPM. That would probably cause some interesting problems. The Crane is a favorite conversion around here but I'm not sure how sensitive it is about operating voltage.

    2. Really need to know you timing setup. Larry's timing setup sticky in the wrenchin' section is really helpful. You really should have at least 14-16+ deg of initial advance with about 34 total. For racing the no vac advance thing is great but for around town the vac advance will help a with drivability and fuel economy. I've been running it on ported vacuum with a limit of about 10 deg additional advance.

    For reference I'm running right at 10in HG at 850RPM idle in my car. Currently using cam setting 3 but 2 seemed to run about the same.
  2. bdschuch

    bdschuch bdschuch

    Thank Ken and Eric!
    1) Tach: for my tech signal i spliced into my existing lead for my hood tach (soldered connection) very near to the TB. is there a good way to test the signal?

    2) cam: maybe I should try cam setting 3 just to see what happens. Will that negate all of the things I've changed already? not a huge deal i guess. the biggest changes I've made were to accel pump and fuel at crank.

    3) ignition: I was having hard start problems a couple years ago and traced it back to the pertronix needing a full 12v to fire off. I found that if I turn the key forward for 5 sec. before cranking, it started better. I then ran a 12 ga wire from the batt to a fused switch under the dash and then back to the coil to provide full 12v for startup (this setup sux). I just don't want to spend another hundred bucks on a conversion and have the same outcome. I sure wish the GM HEI distributor would fit beneath my GS air cleaner, simple and reliable.

    4) Distributor: Has anyone heard any good or bad about DUI HEI distributors? or if they fit with GS air cleaner? I've reaed some about it and they seem to have a good following and reliability record.

    5) timing: I'll try to check timing this week. I could check my engine build sheet but would rather check it.
    thanks again guys.
  3. real82it

    real82it Silver Level contributor

    Got my first chance to test pure highway mpg with the FiTech yesterday. 13mpg. Previous with carb was 11mpg. Good stuff.
  4. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    That's actually pretty awesome, that is tick over an 18% increase! A lot better than 2 mpg sounds. This means if you could of went 250 miles on one tank, now you can go 295 miles on one tank of fuel! 18 more miles per 100 that you drive, not to shabby, the FITech will pay for its self in no time.

  5. sailbrd

    sailbrd Well-Known Member

    I have a new/old issue about the temperature measurement with the FiTech unit. Last week I had a head crack :af:(nothing to do with the FiTEch) and the motor overheated. My mechanical gauge showed the overheating and the Fitech did not. Gauge was at 230 and rising, controller was showing 175. Have heard others saying the FiTech reads 20 degrees low. This is much worse.
  6. bdschuch

    bdschuch bdschuch

    That REALLY sucks, I'll have to watch mine closer because mine reads way lower than the mechanical as well. When i first noticed the difference between the 2 I checked the intake temp at the sensors with my IR gun and the fitech temp was very close to that reading so I assumed that my mechanical was reading high. I'll check more places on the engine just to compare.
  7. bdschuch

    bdschuch bdschuch

    We had a car cruise last weekend with a few buddies. with a fair amount of back road cruising at 40-60mph a few burnouts and about 7-8 miles of very spirited corner to corner action in the 100+ MPH range, I flled up the tank and averaged 15 MPG. I had never gotten 10 before.
  8. Robs455

    Robs455 Well-Known Member

    The efi system seem to be a good thing and I'm very interested.

    But one question is not clear, the throttle body size. The meanstreet supports 800 hp with 8 injectors and is rated at 850 cfm.
    But an 850 cfm carb is right for a mild 455 but never enough to feed a 600+ hp engine, why are these EFI units rated @ 800 hp with just 850cfm :confused: On their homepage the say just the injector size is the limiting factor.
  9. sailbrd

    sailbrd Well-Known Member

    cfm ratings are way over rated. It all depends on how the rating was determined. There is no consistent standard for doing this. When I was running Holley carbs I tried an 830, 850, and two 950's. On of the 950's was worked on a bit. The 830 was a circle track carb. Not enough difference in them to spit at. The two best were the 830 and worked on 950. Both pulled the same 112 mph trap speeds.

    The best way to find out if the throttle body has enough flow is with a vacuum gauge. If you are seeing 0 inches of vac at WOT the body is flow all that it can.

    My point would be that the cfm number is very rough guide to the airflow your motor needs.
  10. Ken Warner

    Ken Warner Stand-up Philosopher

    FiTech facebook page linked above is quickly becoming the best source of info on these systems.

    Word of warning, you will have to wade through a bunch of the same questions over and over and OVER again to find whatever you are looking for.
  11. sailbrd

    sailbrd Well-Known Member

    Just the nature of facebook. What is really needed is a web site. Harder to get started but would be so much better. Someone could make a few bucks on this.
  12. Tomahawk

    Tomahawk Gold Level Contributor

    I installed the FI Tech unit last year, and it ran well enough at first. Then, as others have described, it would act like the fuel feed was being cut off when I tried to stomp on it, whether from a dead stop or at highway speed. Nobody makes gas tanks for a '72 Riviera so getting the EFI one from Tanks, Inc isn't an option.

    Is my understanding that replacing the FCC with the PowerSurge from RobbMc should solve the problem correct?
  13. Ken Warner

    Ken Warner Stand-up Philosopher

    Based on what I have read, the FiTech FCC can be made to work. You may have to do a BUNCH of reading over at the chevelles site or the Facebook page though.

    Things I've seen people doing...
    1. Depending on what you have going on you may need to open up the can and replace the needle and seat.
    2. I've seen people turning the PWM way way down on the electric pump inside the FCC to reduce heat.
    3. Run a dedicated vent line BACK to the tank.
    4. You have to keep the FCC away from sources of heat.
    5. Watch inlet pressures from the mechanical pump

    All that being said I have not read anyone post anything negative about the RobbMC fuel system. But if you already have the FiTech unit I think you can probably make it work for less money that you would spend on a new RobbMC unit.
  14. Tomahawk

    Tomahawk Gold Level Contributor

    Is the stock fuel return line pressurized? I'm wondering if I screwed up by plumbing the vent line from the FCC to the return line.
  15. Ken Warner

    Ken Warner Stand-up Philosopher

    Not sure what you are saying here?.. He about some pictures?
  16. Tomahawk

    Tomahawk Gold Level Contributor

    On the 1972 Riviera (with A/C), the fuel sender has a 3/8" fuel feed line and a 1/4" return line. Normally, the mechanical pump would have a rubber hose to connect to the steel return line; however, I plugged it on the mechanical pump, and routed the vent line from the FCC to this steel line.

    By pressurized, I meant is the return line trying to suck gas from the FCC?

  17. Juze86

    Juze86 Well-Known Member

    Hi, I'm planning to go efi, is there a distributor for Buick 350 which works with FiTech's timing control feature? Now I have HEI and that does not work with it right?

    edit: I made some research and If I understood right I can bypass my ICM and use only magnetic trigger signal to control my timing with Fitech. Is anyone done this?
    Last edited: Jul 25, 2017

    MT BUICKNUT Well-Known Member

    So after having this on the car for a while, what is your opinion of the system?
    Thanks Rick
  19. Ken Warner

    Ken Warner Stand-up Philosopher

    Still really pleased with my FiTech Meanstreet 800 system. Spend time reading here at about the various fuel injected installs from the various people and you will avoid most of the problems people encounter with these sorts of systems. Research is easier and cheaper than throwing parts at the car hoping to get it running right after the fact.
    300sbb_overkill likes this.
  20. NOTNSS

    NOTNSS Gold Level Contributor

    Without reading the entire thread for the 3rd time (or so) can anyone tell me if there's a definitive answer on how the Mean Street 800 or other FITech works with spread bore intakes (Edlebrock B4B)? Last I heard it could go either way, good or not, and of course FITech says they work with "any manifold". Don't want to make a long-term headache out of this since I might road trip through Montana, etc. for the summer now that I'm RETIRED!
    If I had to change the intake to a TA SP1 or such I'd have to get it machined to match the deck height (zero deck currently) and ports to match correct? That's the part I'm hesitant about. I guess I hand the B4B to the machine shop with the new intake and let them do the measurements to match it all up? Sounds easy enough if that's the case.
    Plan would be to do a complete tank to EFI unit fuel system (Tanks) to avoid the problems with the underhood unit.

    Thanks gang!

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