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

Can you just fit -8/-10 to -6 AN adapters? That will effectively reduce the whole shaboom to 3/8" flow rates tho'.

 

I can do the inlet with a fitting to do -8 no problem. That is a standard carb inlet. I think on the return line I can just get a male/male -10/-6 reducer and run a short -6 line. Since FiTech is set up with -6 standard should be no problem with the lines I have.

 

There are people dyno'ing 800HP and running 8's in the 1/4 on 3/8th fuel line with EFI. It's more than adequate for 99.9% of any Buick's running EFI. I'd consider this a non-issue.

 

Thank you for posting that. I just bought the 600 power adder unit with thoughts of getting nitrous in the future, and planned to vent the fuel command center using the charcoal canister line. According to the chassis manual I just looked at, I should have a return line, but when I replaced the pump with the Robb MC unit a while ago, there wasn't a return line hooked up. Hopefully it's still there (and capped).

Are you using the timing control feature?

 

Agree. I went with the -8/-10 on the recommendations of the pump manufacturer. SX Performance (now Edelbrock) seems to like overkill on their specifications.

 

I am not using timing control. I run an MSD 6al2 programmable box. I would consider switching over, but no start retard on the FI tech control.....and I need it.

If your car doesn't require start retard I would suggest looking at using it.

I also ran a data log today for the first time.....went to download it and what do you know, programming software for the tables the unit uses. Have to looked at it in detail yet, but some folks said they wanted to be able to program their own inputs rather than relying on only the self learning. Apparently you may be able to.

I am still very happy with the performance. Driving experience continues to be great. I did find I had an issue with hot starts.....sometimes I could not get it to fire without cranking for awhile if I tried to start a few minutes after I shut it off and the engine was close to full temp. (It did this, of course, while I was at the engine builders shop showing off the car and FI Tech unit). A quick call to FI tech support.....they advised to adjust my idle/throttle blades at temp until my IAC count is between between 5-10. Once I did this, problem is solved. Has started fine each time since adjustment.

I have one more issue I need to try and fix....but it is a minor one. If I am cruising at low rpm (1400 ish?) with the throttle cracked open just slightly and the car shifts from first to second, there is a momentary drop in rpm after the shift has finished and the car hesitates very slightly. It recovers quickly and then goes on fine. I need to call tech support and see what they advise.

 

It sounds like you are having a good experience. For as new as this system is you have had very few problems and good tech support. I will probably order my system next week.

 

I'd be curious to see their timing control tuning options. On my two EFI'd cars I control cranking timing two ways, and really only one way is needed, but if it's in a table format (typically RPM vs MAP), then setting the fields of 500rpm and high kPa (>~85kPa) to somewhere around 5-10 of timing, will effectively act as a starting retard and as soon as the engine is up to running rpm (600+) it will be at "normal" commanded timing. Alternatively, they may have a fixed cranking value, at which you simply program in the timing you want for cranking (IMO 5-10) and the FItech unit should utilize this value during cranking rpm (which it should know the difference between cranking and idle). Typically cranking at 10 or less of timing usually allows the engine to spin up faster on the starter.

 

I have also been looking into getting a TBI system.
Then recently I came across this FITech system and it looks promising. :TU:
My only concern is the CFM rating of the throttle bodies.
I have recently e-mailed them to get these figures. :Comp:
All of them, except for the MPFI unit (900 CFM), are rated at 835 CFM. :eek2:
This seems a little low for a unit that is rated up to 1200 horsepower. uzzled:
Our Buicks tend to like a lot of CFM.

 

Can you compare how a carb flows with how the TBI system flows? Don't know.

 

Have we addressed whether the FI unit will work equally well with a spreadbore intake (Qjet)?
I know it will fit and function but do you suppose there might be a performance downside?

 

Good question.o No:

CFM is CFM ?? uzzled:

This is the main thing that has me a little hesitant with any of the TBI systems.

Standard models say that a 463 that runs up to 6000rpm doesn't need more than about 802 CFM.
...we know that even mild performance Buicks like more CFM than that.

 

I would think it would depend on the application. o No:
If you use a spacer/adapter then, I think, it would work as well or better...again depending on the application. o No:
Maybe not if you use a flat adapter. o No: Depends on your application and what it will like. :TU:
It should work just fine either way. ray:

 

Yes'ish. CFM flowing through a carb will be loaded with fuel and air, versus a multi-port injected engine that the CFM flowing through the throttle body will be straight air, and thus support more HP on technically the same CFM because the fuel is introduced later. The TBI's, I'd guess it matter's where they introduce fuel, as it appears some of the new style TBI's introduce the fuel below the bottle neck (throttle blades) and some introduce fuel after the bottle neck. So is it wet CFM or dry?

 

Good point about the wet v. dry CFM...definitely some difference there. :Smarty:

I think the Holly "Terminator" and FAST 2.0 systems both inject the fuel below the throttle blades (maybe others too).
But this FITech adds the fuel just above the throttle blades. Check the third video down here http://fitechefi.com/default.asp.pg-MediaVideos

Have been trying to find some back to back performance comparisons of any of the TBI systems vs. a good carb - on an air thirsty Big Block...haven't had much luck. uzzled:

 

I think you can get too wrapped up in CFM ratings. If it is over 800 CFM then you should be good for most 455's, even some pretty stout ones. The best Holley I ever had was an 830 I got used from an oval track racer. Sold it to get a custom 950 that was good but not better. So if the Fitech is running around 840, then it should handle 99% of what most of us are running. Have to think it is also a pretty clean air flow with no boosters involved.

 

You're probably right. :Smarty:
Its just really easy to worry that you're missing out on power if you don't have enough CFM. ou:

Might miss-out on a few, top-end ponies - but probably will work better all around. :3gears:

 

Update:

Since install I have had intermittent stuttering issues at 4000+ rpm. I called FI Tech back in January and they insisted it could not be their TB unit or fuel command center. Even when I said I thought I observed fuel delivery issues with the fuel command center, they said not possible....."it either works or it doesn't". So, believing what they said, I then thought it may be an ignition issue. I then thought that my fuel supply system had an issue. I am not even going to go into all the things I did to try to troubleshoot the problem but it was a giant pain in the butt and fairly expensive. In short, I tested or replaced every aspect of my original fuel system up to their fuel command center and also tested my entire ignition system, including swapping distributors and coils.

Because it was intermittent it was very hard to troubleshoot.

Finally, about three weeks ago it became constant above 4000 RPM. I called FI tech and they had me send them some data logs. It was very clear from the data logs that the car was going very lean. As lean as 18:1 at 5000+ rpm under WOT! Even then, after I explained everything I had den, they would not admit that the problem was theirs and insisted the problem had to be on my mechanical pump side or that I had some kind of blockage in the fuel line going to the Throttle body. I had recently replaced my gas tank, fuel pick up, and had my Robb MC pump checked and rebuilt by Robb MC while trying to fix this issue.......I knew there was not an issue on the low pressure side. I replaced my high pressure side supply line and verified no blockage. Once I reported this back, FI Tech escalated to next level support. He then started trying to help, had me ground the unit directly to my battery, but continued to insist the issue was either an obstruction or some type of pre sump problem on the low pressure side. I did not want to mess with running a high pressure line and gauge to someplace I could monitor while driving. I finally ended up taping a phone to the underside of my hood and took a video of their fuel command center pressure gauges during a wide-open throttle run. https://youtu.be/TcrKeua5ipM That video clearly showed my low side pressure holding rock solid steady at 6 pounds and their high side pressure dropping to zero. Clearly, the problem is on their command center high side pressure fuel delivery......a problem with fuel level, flow, or pump pressure under load in the fuel command center.

After seeing the video they agreed to issue an RMA and repair the unit. They could not send me a new command center because they don't have any and are back ordered.

Sent the unit back and told it was usually "a 1-2 day turnaround". On day 5 after they had received it I hadn't heard anything. I called multiple times and sent emails requesting a status update. Nothing. Talked to my support person and explained this was a difficult problem to troubleshoot, could be inermittent, and requested he make sure they put a NEW fuel pump in his fuel command center. Got no follow up or feedback after 2 more inquiries......

I finally got the fuel command center back yesterday. Installed in car. First run was fine. Second run and third run WENT LEAN AGAIN. Same intermittent performance. Unbelievable.

I called FI Tech today and they could not confirm what had been done to "repair" the unit. Said that if the Command center tested ok on their bench 454 motor that the fuel pump probably was not changed! They just sent it back to me........

Frankly, I am pretty disappointed in their recent customer service and sick of dealing with this. I suspect they are victims of their own success. They have grown very fast, are in summit, Jegs, etc. still getting proper support in place I guess.

Every time I test this I am very worried about damaging my engine. 18:1 AFR at 5500rpm WOT is not good! They are supposed to call me back tomorrow with next steps or suggestions.

If they can't resolve this, I think I am likely going to order either the RobbMC powersurge unit or maybe a new Tanks EFI gas tank with internal pump. I will probably try the power surge unit first. I called the guy at RobbMC and he said he actually runs the FI Tech TB with the powersurge on his personal vehicle. Easy hookup....in addition to what I have, since they are internally regulated, I just need to run a return line from the TB back to the powersurge. I am still a fan of the FI tech throttle body unit, but am definitely questioning the fuel command center capability.

 

Read everything could find on FITECH installs before I bought mine last week and the ratio of complaints goes from near zero to probably 50% or more when the fuel command center thing gets installed with the system. It seems like a great idea on paper but It looks like there are some bugs to be worked out in the real world.

 

And now I am pissed. Found this thread on a chevelle site. Almost the same issues I am having.....yet FI Tech is acting like this is the first time they have seen this.........http://www.chevelles.com/forums/89-...ter-review-install-w-pics-53.html#post8748929