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Hello all, I have a 1992 FD3S (JDM) 85k miles. I just installed a Rotary Run Racing Intercooler and after the install, it started idling really high, and surging from 1400-1800rpm as well as get boost spike up to 12psi. It normally idles at 750-800rpm smooth and always boosts up to 10psi, never more. I have checked the TPS Voltage and it is perfectly within Spec. I had to relocate the AST but I dont think that would cause any problems with surging Idle. I also relocated the Blitz BOV and shortened the vacuum line on top that runs to the Upper Intake Manifold. Havent gotten a CEL or any warning lights. I also have a "Poor Mans Sequential" vacuum line setup as well as changed all the vacuum lines in the Rats Nest about 3 months ago.
Mods: Stock ECU, HKS Twin Power, Blitz BOV, HKS Pod Filters, Rotary Run Racing Intercooler.
Any ideas what could be causing Hunting after just changing the Intercooler and relocating some things?
Common problem, more so with a PFC tho (there quite a few threads on the subject). Since you checked your TPS, i'd start with checking for vacuum leaks, esp around where you worked.
You may want to look into upgrading your ECU and getting a tune. And a duct for the IC
Common problem, more so with a PFC tho (there quite a few threads on the subject). Since you checked your TPS, i'd start with checking for vacuum leaks, esp around where you worked.
You may want to look into upgrading your ECU and getting a tune. And a duct for the IC
Thank you! I was on the hunt all day for a vacuum leak yesterday and found a cracked hose going to the upper intake manifold, fixed it but still hunts for idle. I searched even more and found nothing. It was only that one. It was still hunting/surging but now its hunting between 1400 and 1600 really slowly. Any other ideas? Could it be ignition related? Bad plugs/coils?
Common problem, more so with a PFC tho (there quite a few threads on the subject). Since you checked your TPS, i'd start with checking for vacuum leaks, esp around where you worked.
You may want to look into upgrading your ECU and getting a tune. And a duct for the IC
I had a Power FC for S6 before I ended up realizing this is a S8 Motor. The pinout on the ECU is different with multiple extra pins on the S8 ECU(N3F1).
So, I have officially exhausted my knowledge of how to fix/diagnose the issue. I have checked the alternator and battery for voltage problems and replaced all the fuses, I have smoke tested the vacuum system, wasted countless cans of starting fluid as well, checked the TPS again and again, ran a diagnostics check for codes and no codes were being thrown... I also noticed that when the AC and/or the headlights are on, it drastically changes the idle from 1400-1600 to 1800-2200. That's about as far as I've gotten... New S8 Power FC is on the way though...
