JeffTsai

iTrader: (1)

Actually, it's a common problem that FIC users have if the unit is not setup properly. If your cam/crank sensor signal & grounds are not 100% and are noisy, it will cause the FIC to pick up a bad signal at higher RPM. Your symptoms will be difficulty revving past 3500-4500rpm and it's a common issue. The easy fix is to install a 2.2K(just a baseline, you might have to go higher or lower) ohm resistor parallel to the cam and crank sensor inputs and tie them into their respective grounds with the resistors. The good test for this is to run the engine NA (just undo the intercooler piping so the turbo can't build boost), and free rev the engine. It should go up to the 6500rpm stock redline no problem with just the stock ECU connected. If you hook up the AEM and do the same, but it cuts at 3000-4500rpm range, then you have the common faulty ground. Make sure all of the settings in the tuning cells are all set to 0 while you perform this test(this ensures that the FIC is not screwing with the signals).

Personally, I have never had this issue on any of the cars I've setup with FIC because I am extremely adamant about getting the best possible ground to the unit and sensors grounds. I check the sensor grounds and ECU grounds to make sure the resistance is as low as possible. I even add extra ground straps in some cases to assist grounding. Many people go with the easy resistor fix, but it can cause some other issues such as a slight timing drift.

LexCafe

Ok I did a few tests in the last few days.

First, I disconnected the intercooler and put the engine back to NA. Running stock ECU with nothing else hook up. The car had problem idle. Turn out, I had a bad MAF sensor. Replaced the sensor and it ran perfect. Rev all the way to redline with no hick up.

Second, I installed the extension harness with the by pass plug. It rev to redline with no hick up (still in NA). This means the wiring is correct.

Third, I installed the FI/C with everything set at 0. It started to hick ups above 3500 rpm and will not rev pass 4500rpm.

Jeff, I believe I'm having the problem you mention above. I have the 2.2k resistors but not sure how to install them.

LexCafe

Just an update.

After a quick call with Jeff to confirm the installation of the resistors, I bridged the CAMI+ and CAMI- with 1 resistor, CRKI+ and CRKI- with another resistor and the problem was solved. Thanks to Jeff for the good info.

Feeling boost for the first time was awsome. 4000rpm to 6500 rpm was just crazy. Thanks for all of your inputs guys. Now on to tunning.

JeffTsai

iTrader: (1)

Good to hear that fixed your problem.

Vroomin350

iTrader: (28)

Nice to see fellow members able to come on here and find solutions to their problems. Personally I have never owned a boosted car but it doesn't mean it'll always be that way. Till then, I'll read these and learn


Aside from pump and the above mentioned what else are you upgrading?
Will you 1/4 the car?

LexCafe

Internals are stock. I just replaced head studs, main studs and rod bolts with ARP. I also replaced the head gasket with 1.3mm Commetic HG. The whole motor was torn down and every seals and gaskets were replaced.

I'm planning to take the car to Dallas to have Jeff tune it this Labor Day weekend. Onced it is tuned than yes I WILL take it to the track and get a few runs.

tryitonce

iTrader: (1)

Hello @ Burton......do you still have the harness...if so please message me so that I can get that from you....my fic is in the glove box...is it long enough to reach from there to the ecu ? Please let me know asap...thanks in advance.

tryitonce

iTrader: (1)

Hello @ Jeff.....if I get the harness from boomslang will I still have to use the resistors....as I am having this same issue with my 98 gs.....Thanks

Burton

The resistors are already in the harness from boomslang.

Ben

tryitonce

iTrader: (1)

Hey Ben....I didn't hear back from you and ordered the Harness from Boomslang...thanks anyway...and thanks for the info...i appreciate you and the forums.

tryitonce

iTrader: (1)

I have a 98 leus GS300 with a gte supra block and ge head. I Ihave 850cc injectors and 62-1 turbonetics turbo,44mm wastegate and am using the AEM fic and the boomslang harness..I can't pull fuel from the car without it running poorly.(idle 12.9-13.1 runs perfect). I have noticed that the fic is reading voltage of 12.6 to 13 while the voltage on the alt is at 14-14-1.My car breaks up at 5200 rpm (on the tach in the car) like it's at redline and the fic was reading 6200. I need help in the worst way.I believe that you are the person knowledgeable enough to help me out. Thanks

JeffTsai

iTrader: (1)

The 850cc injectors are too big for the FIC to drive correctly. It will drive them ok during driving and boost, but at idle the FIC can't pulse them low enough. I've tuned a car on the FIC with 800cc injectors and the lowest I could get a stable AFR to idle smoothly at was around 12.5-13:1. The biggest injectors I would recommend on a FIC are 600-700cc or so. The eManage Ultimate has a different injector driving strategy so it can idle up to around 850cc injectors ok.

Did you check if your tune is ok in that spot? If you're running pig rich up top then it will cause a really bad misfire which could be like what you are experiencing. What are your plugs gapped down to, and how old are they? And also how much boost are you running?

ksu1998

iTrader: (1)

Good to hear you are making progress hey Jeff move to Kansas CIty so I can have you tune my car

Is there still a 1/4mile track in Joplin??

tryitonce

iTrader: (1)

The plugs are pretty new...not sure of the gap...what would you recommend...boost is at 12 pds......So I need smaller injectors also ? I know it's running pig rich up top. Thanks for taking the time to help me out....if no one else appreciates you....I do....lol