FITech Fuel Injection Hesitation

jjmacswt

jjmacswt

n00b
Nov 1, 2019
4
3
1987 Monte Carlo SS

I transplanted a new 350 crate motor, added a new gas tank, fuel pump, FITech Fuel Command Center 2 and FITech Go Street EFI 400 hp throttle body. When driving the following issues surface:
  • Letting of the accelerator and coasting, the engine will shut off and then turn back on between 850-1000 RPM's. Sometimes it flat out stalls and I'll restart it on the fly.
  • If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation.
FITech hasn't been knowledgeable when my mechanic tried to deal with the hesitation and frankly, it sounds like they just don't know. The self learning doesn't seem to work with this system unless I need to go drive 200 miles nonstop. My mechanic tried programming via leaning out the fuel delivery and it helped a little but it left him stumped as well.

Has anyone had any success tuning one of these systems and would consider sharing their programmer settings? I'm not a mechanic but I think I can muddle through the programmer and change the settings.
 
fleming442

fleming442

Geezer
Dec 26, 2013
9,276
113
Play with the TPS adjustment steps. I forget where in the menu it was. Get it hooked to a laptop, and tuning is much easier than the handheld.
Also, in the initial set up, there is a selection for the generic cam profile. try playing with that some.
 
Wageslave

Wageslave

Royal Smart Person
Jan 25, 2017
1,045
113
1987 Monte Carlo SS

I transplanted a new 350 crate motor, added a new gas tank, fuel pump, FITech Fuel Command Center 2 and FITech Go Street EFI 400 hp throttle body. When driving the following issues surface:
  • Letting of the accelerator and coasting, the engine will shut off and then turn back on between 850-1000 RPM's. Sometimes it flat out stalls and I'll restart it on the fly.
  • If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation.
FITech hasn't been knowledgeable when my mechanic tried to deal with the hesitation and frankly, it sounds like they just don't know. The self learning doesn't seem to work with this system unless I need to go drive 200 miles nonstop. My mechanic tried programming via leaning out the fuel delivery and it helped a little but it left him stumped as well.

Has anyone had any success tuning one of these systems and would consider sharing their programmer settings? I'm not a mechanic but I think I can muddle through the programmer and change the settings.
When it the engine shuts off while coasting down, there should be a setting called Overrun Fuel Cut or something similar. You can either disable it or set the value to 1200-1300 to get away from the stalling. If it still wants to stall on coastdown, try richening up the the idle-no load part of the fuel table as it is probably running lean.
 
CopperNick

CopperNick

Greasemonkey
Feb 20, 2018
206
43
Canada
You mentioned a new gas tank and fuel pump. By any chance did you happen to go with the booster pump that FI-Tech offered as a fuel delivery upgrade alternative for those who didn't want to go with an in-tank pump? Reason I ask is that the earlier versions of those booster pumps came unbaffled internally. That means that when your vehicle stops or slows suddenlt, like when you are trying to deal with idiots ahead of you who can't figure out where they are going or what lane to be in, the absence of the baffles causes the fuel to move away from the pickup in the booster. it momentarily starves and the motor cuts out. Had that issue the first summer I drove my FI-Tech and I almost went nuts trying to figure it out. Fully warm, the IAC reading on the micro-monitor ought to read between 4 and 10. Don't try anything with it while the mill is warming up, the reading bounces all over the place. By way of interest, if I am coasting, the engine does not shut down, but you have to feed in acc pedal gently or it will bog. FI-Tech says I ought to lighten up the return springs so the butterflies will open more easily and less abruptly. I do most of my own driving on the street; would not want to risk and interstate run due to concerns about having stop abruptly and having the engine lose fire until the booster caught up. My own plan is to either convert the tank to take an electric pump, or go in-line electric. Tank is supposed to be better but my tank is both new and about half full which is a bad combination to take an drill-driven hole saw to. FI-Tech has mentioned that it has upgraded its boosters by adding baffles but for the price of a new booster you can also get the tank pump and have a better system.
 
S

Supercharged111

Master Mechanic
Oct 25, 2019
427
93
The self learning likely only applies to VE. There is A LOT of other stuff to tune to make it right, you need a tuner not a mechanic. As indicated, transients are where you need to start.
 
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TURNA

TURNA

Rocket Powered Basset Hound
Jul 24, 2009
10,459
113
Socialist NY
Take it off and put it in the garbage where they belong!!

Nothing but problems and there tech help suxxxxxx


 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
5,597
113
Melville,Saskatchewan
Yah, I was hoping these standalone TBI's would be better than they are. What is the point of them if they run like this and gain 0 mpg over a properly tuned carb? Even guys who like the swap have said 0 mpg gained. Isn't that the point of EFI, better mileage and drivability? I saw an AMC 6 build because FItech was their sponser, clearly the issue was their intake modification. Funny when they put on a 750 carb on, the 6 made the power they wanted, which wasn't much to begin with 242 hp, the FItech definitely could not learn fast enough on the dyno, didn't break 200 hp. Too bad, I had hope for these EFI setups, just shows, you get what you pay for.
 
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