TRURX7

I have tried adjusting this puppy at the extremes and I still get boost cut. Do I need to reset the computer every time I adjust it? I recently installed a fluidyne custom radiator and had to relocate the battery. This leads me to my next question, How important is the ground to the block from the battery? Could this be causing my fuel cut? I see my Phantom boost gauge go fast to 8-9lbs then immediate fuel cut. Should I run some more grounds or is this problem not related to the fuel cut? Should I move the HKS FCD near the sensor or should I keep it next to the ECU? Please help me, I am getting spanked by 00 Mustang GTs (never happened before, I used to run 13.9 @ 101mph)

Please give me suggestions if you have the HKS FCD.
Thanks
TRU

Scott 89t2

as for the grounds. what I did is you need to run one from the battery in the back to the frame. 2 feet max, no need to be longer. 0 or 2 gauge.

I took the old ground wire that was on the battery, and grounded that to the body in the front. I also added an 8 gauge ground from the intake mani to the firewall.

for the FCD. you sure it's in right?

TRURX7

I will re-check the FCD wiring tommorow. Perhaps even relocating it. I am also gonna run some welding cable from one of my side posts on my battery directly to the block. I had the 3800rpm stumble before on my NA and running grounds seemed to help quite a bit. I appreciate the responce.

Scott 89t2

oh where is the battery??

TRURX7

On the rear left compartment. Behind my drivers seat The (+) wire is pretty huge, I have the advantage of a battery with top and side mounts so I will run an extra ground from the side post and if I can afford an extra power wire for the (+). I was also considering running an extra wire from the alternator to the battery fuse I installed.

HAILERS

You really need to see if the fcd is clamping the voltage. All it takes is a MITTYVAC or other source to apply pressure to the boost sensor, and a dvm tapped into the brown/red wire at the sensor as it heads for the ECU. Just apply pressure to the sensor and see if the output from the pressure sensor/fcd to the ECU clamps at around 3.65 to 3.7 volts. If the output rises over those figures, then it ain't a workin. If it does clamp, then the problem lies elsewhere. Takes about fifteen minutes to check out in the driveway.

Or, if you don't have a source of pressure, you could tap into the output from the unit and monitor the voltage as you boost the car. Not as accurate, but workable.

TRURX7

OMFG,

I built a FCD that lasted me 4 days because of water, I remember exactly what you mean. My question to myself is, WHY THE F$%^ did I not think of this before!!!

Thanks for reminding me. Damn I feel stupid now.

HAILERS

I've a RB fcd that I bought from Rotary Performance a couple of months ago. Used it for two weeks, then built my own. If your interested in buying the RB one, I'd let it go for fifty bucks. Half price. I like my home made one. Just a thought. Its for a 87 TurboII. Works fine. Just personal preferences.

NZConvertible

That's why DIY FCD's are best wired in at the ECU instead of the boost sensor...