ra_guy
Probationary Member
- 26
- 0
- Dec 12, 2013
-
San Antonio,
Texas
For a while now, I've been having some strange issues at idle. The car seems to fluctuate AFRs more than I've seen previously, and the idle sometimes moves around simultaneously (rich - idle up, Lean - idle down between 900 and 1300 rpm), other times it stays rock steady.
This isn't typical idle surge. I'm on SD and have boost leak tested the entire intake tract to 30psi, no issues. ISC is functioning properly. Fuel pressure stays rock steady. STFT is not the cause. TPS is logging properly 0-100. Checking the "ground timing" box in ecmlink causes the idle to fluctuate pretty drastically(nearly stalling then shooting to about 1400rpm) , which I find odd. Base timing is dead on 5*.
Any thoughts on any of this? I'm running out of things to "fix". I'm on an evo 3 ecu currently, but it's essentially the same as the dsm.
*I should add, I was previously on an evo 8 ecu and was having the same issues, among others (namely isc control which link did fix), so it is not an ecu problem.
**PS: There's a video attached, toward the end there's a knocking sound. I don't think this is related, but any ideas? Keeping in mind this engine has ~900 miles on the build. Sounds like it's in the head, but lifters, cams, valves look great "from above".
This isn't typical idle surge. I'm on SD and have boost leak tested the entire intake tract to 30psi, no issues. ISC is functioning properly. Fuel pressure stays rock steady. STFT is not the cause. TPS is logging properly 0-100. Checking the "ground timing" box in ecmlink causes the idle to fluctuate pretty drastically(nearly stalling then shooting to about 1400rpm) , which I find odd. Base timing is dead on 5*.
Any thoughts on any of this? I'm running out of things to "fix". I'm on an evo 3 ecu currently, but it's essentially the same as the dsm.
*I should add, I was previously on an evo 8 ecu and was having the same issues, among others (namely isc control which link did fix), so it is not an ecu problem.
**PS: There's a video attached, toward the end there's a knocking sound. I don't think this is related, but any ideas? Keeping in mind this engine has ~900 miles on the build. Sounds like it's in the head, but lifters, cams, valves look great "from above".
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