updates and helpful info to anyone using fitech ultimate Ls for swaps. It takes time to get to know a system, playing with it, and familiarizing yourself with all the options and features, here’s some of the things I learned in the last 2 years of having it.
Issue 1- map sensor was reading 113 key on engine off, tried 3 different sensors and brands, all worked fine just something in the calibration or ecu was wrong, I had to go into pro tuning settings>basic> map offset and increase that number from 45 to about 85 to make the default reading about 99kpa for a hair above sea level.
2. Multiple bad sensors, the current software update is 1.53, before I updated it, the tps kept jumping to 33-77, after the update, it was fine. Until after, hard parts starting becoming problematic, I tried fast, standard, Bosch and they were all junk, ended up using 2 different acdelcos and one finally worked and had no dead spots. Iac reset and tps learn is your number one standard for tuning this system and getting it to run correct, use quality sensors, I wouldn’t even bother installing the supplied map/tps and iac. The cts and iat seem to be ok so far.
3. Like 64 nailhead said, DITCH THE C5 REGULATOR/FILTER.
I cannot stress this enough, it is not strong enough to hold fuel pressure with any kind of upgraded pump, even the Walbro 255 I’m using, I went through 2 of them, straight from the dealer and aftermarket wix as well. do yourself a favor and run 2 lines, get an adjustable regulator, (I don’t suggest a Holley) it was constantly leaking and problematic, I can’t speak for the billet one, but I’m going to assume it will seal better. The c5 ffpr would go to 70-75 lbs after a few months. Now rock solid at set 59psi.
4. Ditch the supplied intake manifold. The sniper style knock off intake manifold looks great, and that’s the extent of the pros. It’s terrible for power, has a whistling noise from the metal frequencies, and this thing gets HOT! I’m currently swapping it for the nnbs truck intake manifold, new gaskets, map sensor will need to be fitted with either an adaptor or a remote mount with hose, I’m going to just trim the edge, and use the newer style orange seal, fitech uses ls3 style injectors so I got the adaptors as well and spacers for the truck manifold, you need to replace the rails as well since the injectors are angled in the nnbs manifold, as well as the 92 to 102 mm tb adaptor in my case. You’ll also need to drill a hole in the side for the IAT sensor, get a factory pcv line with the elbow molded into it, twists in, cut the end off, I’m using a sealed catch can so it goes in between from pcv valve to upper fitting on intake manifold, and fresh air supply is going from passenger side valve cover, to throttle body nipple
5. Highly suggest running a fuel pump Hotwire/relay kit. I would Not use the single thin orange wire to power the fuel pump, run it as a trigger for the relay with heavier gauge wires from the battery.
6. Similar to 5, but for the fans, get a relay kit and let the ecu wires activate the fan relays, fyi they run on ground.
7. Make sure your brake switch is wired correctly for tcc lockup. Thankfully in g bodies they come with the 2 sets of pins, one for open, one for closed.
8. Cam profile selection- select the profile based off engine vacume Cam selection is based on vacuum load of the engine. “Cam 1 is for 15Hg or above, Cam 2 is for 10Hg to 15hg, Cam 3 is 8Hg to 10Hg, Cam 4 is 8Hg to 6Hg. These are estimates and you may need to switch between them if the vacuum load is between two different cam settings to get the engine to run better for your application” as well as
Monitoring fuel trim and learn.
9. Fuel trims and learn- ideally they should be in the under 10 range. In my case since my map sensor is offset, I’m running learns in the 20-25 range but the trims are ok.
10. The obvious, vacume and exhaust leaks.
The self learning/tuning software is going to adapt to your engine. If you have vacume leaks or exhaust leaks before the 02 sensor it’s going to constantly adjust and compensate for it just like any other, but it’s going to change the tables and cause problems in performance/drivability/ fuel mileage.
hopefully this helps anyone trouble shooting or having issues with the system, and you can learn from the issues I’ve had, with hours of learning and calls and research to remedy them.
Issue 1- map sensor was reading 113 key on engine off, tried 3 different sensors and brands, all worked fine just something in the calibration or ecu was wrong, I had to go into pro tuning settings>basic> map offset and increase that number from 45 to about 85 to make the default reading about 99kpa for a hair above sea level.
2. Multiple bad sensors, the current software update is 1.53, before I updated it, the tps kept jumping to 33-77, after the update, it was fine. Until after, hard parts starting becoming problematic, I tried fast, standard, Bosch and they were all junk, ended up using 2 different acdelcos and one finally worked and had no dead spots. Iac reset and tps learn is your number one standard for tuning this system and getting it to run correct, use quality sensors, I wouldn’t even bother installing the supplied map/tps and iac. The cts and iat seem to be ok so far.
3. Like 64 nailhead said, DITCH THE C5 REGULATOR/FILTER.
I cannot stress this enough, it is not strong enough to hold fuel pressure with any kind of upgraded pump, even the Walbro 255 I’m using, I went through 2 of them, straight from the dealer and aftermarket wix as well. do yourself a favor and run 2 lines, get an adjustable regulator, (I don’t suggest a Holley) it was constantly leaking and problematic, I can’t speak for the billet one, but I’m going to assume it will seal better. The c5 ffpr would go to 70-75 lbs after a few months. Now rock solid at set 59psi.
4. Ditch the supplied intake manifold. The sniper style knock off intake manifold looks great, and that’s the extent of the pros. It’s terrible for power, has a whistling noise from the metal frequencies, and this thing gets HOT! I’m currently swapping it for the nnbs truck intake manifold, new gaskets, map sensor will need to be fitted with either an adaptor or a remote mount with hose, I’m going to just trim the edge, and use the newer style orange seal, fitech uses ls3 style injectors so I got the adaptors as well and spacers for the truck manifold, you need to replace the rails as well since the injectors are angled in the nnbs manifold, as well as the 92 to 102 mm tb adaptor in my case. You’ll also need to drill a hole in the side for the IAT sensor, get a factory pcv line with the elbow molded into it, twists in, cut the end off, I’m using a sealed catch can so it goes in between from pcv valve to upper fitting on intake manifold, and fresh air supply is going from passenger side valve cover, to throttle body nipple
5. Highly suggest running a fuel pump Hotwire/relay kit. I would Not use the single thin orange wire to power the fuel pump, run it as a trigger for the relay with heavier gauge wires from the battery.
6. Similar to 5, but for the fans, get a relay kit and let the ecu wires activate the fan relays, fyi they run on ground.
7. Make sure your brake switch is wired correctly for tcc lockup. Thankfully in g bodies they come with the 2 sets of pins, one for open, one for closed.
8. Cam profile selection- select the profile based off engine vacume Cam selection is based on vacuum load of the engine. “Cam 1 is for 15Hg or above, Cam 2 is for 10Hg to 15hg, Cam 3 is 8Hg to 10Hg, Cam 4 is 8Hg to 6Hg. These are estimates and you may need to switch between them if the vacuum load is between two different cam settings to get the engine to run better for your application” as well as
Monitoring fuel trim and learn.
9. Fuel trims and learn- ideally they should be in the under 10 range. In my case since my map sensor is offset, I’m running learns in the 20-25 range but the trims are ok.
10. The obvious, vacume and exhaust leaks.
The self learning/tuning software is going to adapt to your engine. If you have vacume leaks or exhaust leaks before the 02 sensor it’s going to constantly adjust and compensate for it just like any other, but it’s going to change the tables and cause problems in performance/drivability/ fuel mileage.
hopefully this helps anyone trouble shooting or having issues with the system, and you can learn from the issues I’ve had, with hours of learning and calls and research to remedy them.
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