Husler005 TSi
Probationary Member
- 18
- 1
- Mar 8, 2004
-
West Michigan,
Michigan
Okay guys--I picked up a 1G 92 AWD (6) a few years back and I've been dealing with idle surge issues since. For a while, I just ignored the idle surge, but it will drive you nuts eventually. It surged when cold up until it was at about 11 o'clock on the temp gauge. I live in the Midwest, and the car was purchased with about 130k on the body, with less than 5k on a brand new OEM rebuild.
The car was acquired bone stock and had many new OEM parts installed recently, including a brand new ECU that was put in by the PO because he thought it might fix the surging. After completing the basic maintenance items and installing a 3.5" exhaust, the car was running great but I still had surging issues, so I began to read up on the various tech articles to ID the issue.
Over the course of a year, I cleaned the TB, EGR valve, intake, t-stat housing, and replaced the TB gaskets, ISC motor, BISS screw and o-ring, and temperature sensors (AC and gauge). The car still surged when cold. Fast forward another two months, and I had installed new poly motor mounts to see if this may be the issue. Car still surged when cold. Then, I replaced the FIAV valve with one from another 4G63 (NT) and did the screw mod to tone down the transition from cold to warm idle. This seemed to fix the surging when the car was cold--between nothing on the temp gauge until about 10 o'clock, but the car started surging once you hit the second mark on the temp gauge and did not stop, even when the car was warmed up.
Now I've done pretty much everything in the book to fix idle surge, so I gave up for now and continued to drive the car as a DD. Since the poly motor mounts were very stiff and not even my wife wanted to ride with me any more (the vibrations were exacerbated by the idle surge), I decided to regress back to the stock OEM mounts (four brand new Mitsu "roll stoppers").
Immediately after running the car with the new OEM motor mounts, the idle surge issue went away completely and has not come back after 2k miles.
Thoughts? Anyone else experience idle issues after installing poly motor mounts? The mounts I used that may have caused the idle surge were Prothane mounts. They were replaced by OEM Mitsu mounts.
The car was acquired bone stock and had many new OEM parts installed recently, including a brand new ECU that was put in by the PO because he thought it might fix the surging. After completing the basic maintenance items and installing a 3.5" exhaust, the car was running great but I still had surging issues, so I began to read up on the various tech articles to ID the issue.
Over the course of a year, I cleaned the TB, EGR valve, intake, t-stat housing, and replaced the TB gaskets, ISC motor, BISS screw and o-ring, and temperature sensors (AC and gauge). The car still surged when cold. Fast forward another two months, and I had installed new poly motor mounts to see if this may be the issue. Car still surged when cold. Then, I replaced the FIAV valve with one from another 4G63 (NT) and did the screw mod to tone down the transition from cold to warm idle. This seemed to fix the surging when the car was cold--between nothing on the temp gauge until about 10 o'clock, but the car started surging once you hit the second mark on the temp gauge and did not stop, even when the car was warmed up.
Now I've done pretty much everything in the book to fix idle surge, so I gave up for now and continued to drive the car as a DD. Since the poly motor mounts were very stiff and not even my wife wanted to ride with me any more (the vibrations were exacerbated by the idle surge), I decided to regress back to the stock OEM mounts (four brand new Mitsu "roll stoppers").
Immediately after running the car with the new OEM motor mounts, the idle surge issue went away completely and has not come back after 2k miles.
Thoughts? Anyone else experience idle issues after installing poly motor mounts? The mounts I used that may have caused the idle surge were Prothane mounts. They were replaced by OEM Mitsu mounts.
