High Impd to Low Impd injectors via resistors..WOT..sputter x3..then fast, fast, FAST
 

I just recently swapped all my factory injectors with 720cc low impedence. I ended up using the Radio Shack 10 watt 10 ohm ceramic/fireproof resistors. I wired them in the engine bay right before the injector connectors since they have a performance rating in heat up to -55 degree C to +275 degree C. They are soldered and vey clean. I am running an HKS F-con with the GCC. The circular rotary switch in the F-Con is turned up three clicks for improved fuel delivery and I have the GCC turned to the max in richness in all 6 rpm ranges. My AFR is a healthy 11.0 all the way to redline at 13 psi.

Here is the problem: Full throttle at ANY rpm range I get a hesitation, 3 little sputters to be exact and then the cars pulls hard to redline. No matter where, 2900, 5500, 4125 rpm. Now I fixed my 3800 hesitation problem with grounds a few months back and they are all still very clean. My TPS is within limits via FSM. The car only started doing this after resistor install.

My friend says those are pretty high wattage resistors to be installing just for injectors. I am a noob at some electrical stuff and have heard countless people here on this forum say those are the type you use. Their results have been fine too.

the only thing still factory on my fuel system is my regulator and my rails. Pump, injectors, fuel electronics all upgraded. Engine is street ported with a hybrid S5 TO4B 60.AR. I jusy recently did the throttle body upgrade and at first thought the problem was the expected hesitation when you hit the gas too soon. But the sputter happens also when easing into the gas to full throttle. Almost as soon as the secondaries come online or when I am building boost . Intercooler couplings are ALL good and tight.

?

By the way, the search feature found me nothing. Same old 3800 hesitation shit.

What kinda fuel pump?
What is the TPS max resistance?


-Ted

I'm not an expert on the F-Con since I've never even seen one, but it sounds like the map is too rich. Does the F-Con control the accellerator "pump"? The ECU could be dumping way too much fuel into the engine since that function sort of assumes a fixed injector size.

Don't listen to this person, he has no clue.

My pump is a 480 lph pump from RX7.com, an my TPS reads 4.96 ohms at WOT.

I suspected it might be the F-con since it is programmed for only 550cc injectors. I am going with the RTek 2.0 very soon.

The problem is just very odd but what do I expect for running incompatable hardware with the fuel computer.

"480"?
Was that a typo???

What kinda FPR?
What is your base pressure set at?


-Ted

40 psi base pressure. 480 lbs per hour. My regulator is factory.

40 psi under boost. sorry :)

Unless you have had something done to that FCON they were chipped to run the 550's.So adding 720's for primarys/secondarys is going to make it run pig rich.They ran pig rich even with just the 550's off boost/low boost.That dial on the FCON scales the whole map if I'm not mistaken ,so if you up the dial you are adding fuel everywhere.The GCC isn't going to do much for you since it only has like 5 or 6 "fixed" rpm adjustment points and probably not where you need them.If you wanted to run larger then stock injectors with a piggy back computer your best bet is the greddy emanage "blue" which has 16x16 maps and ignition control(well ,allows timing retard at least) and also has a built in additional injector controller to boot.

480 lbs / hour translates to roughly 300 lph.
That's an aweful amount of fuel for the stock FPR...
On top of that, you're jacking the F-CON adjustment up - try bringing it down or even back to zero?


-Ted

I'll try it but when I recieved it, the setting was at 3 and with the GCC maxed in all ranges, the fuel system was pushing 12.5-12.9 on my wideband around 6500rpm. When I set it at 5 on the f-con AFR is safe. I think with my turbo and my big street ports I am just maxing out my fuel managment system. Even with 720's all around I think they are getting to the max point on the duty cycle. I am pushing around 320 at the flywheel(just a guess though, no dyno yet until further proper tuning).

What does your o2 read when it sputters? Lean? What brand/type of sensor are you using?

Do you know what trim the compressor wheel is?


-Ted