90gst_sean
15+ Year Contributor
- 566
- 10
- Apr 9, 2006
-
Seattle,
Washington
This is an FYI in the hopes that it will help someone else with the same symptoms.
Like the tittle says...
Symptoms: The first thing that happened was an over-boost issue while accelerating onto the freeway one morning (lucky for me I noticed the gauge as this happened and was able to pull my foot off the throttle as the needle was clearing 22psi @ 4000rpm's. The car wasn't fully dialed in and I hadn't yet tuned for anything above 12psi; the tune was no where near ready to be boosting 20+psi. Reviewing the log showed a small knock spike of only 5 degrees. My water injection system truly paid for itself this day!).
A few days later, with the car running great except of coarse for the boost controller issue, out of no where the engine began to hesitate when boosting over 1psi. I immediately figured the problem boost leak related and likely to wined-up somewhere near the boost controller. My only concern at this time was how could a small vacuum hose, like the one's that run between the turbo j-pipe > Boost Controller > and Waste-gate, leak enough to cause the engine hesitation of a major boost leak.
NOTE: the fancy vacuum hose sold at your local auto parts store is garbage! You're better off purchasing the OEM-replacement vacuum hose they stock in the back room -- it'll last longer; I promise.
Solution: In order to fix both problems I replaced all the vacuum hose running between the turbo j-pipe > Boost Controller > and Waste-gate. This has thus far done the trick.
There must have been a small leak in one of the faulty vacuum hose I replaced at the boost controller because my last tune had idle 'air-flow-per-rev' dialed in at 25Hz (+/- 1Hz), and now the car idles around 28-29Hz. -- Looks like it's time for more tuning...
Like the tittle says...
Symptoms: The first thing that happened was an over-boost issue while accelerating onto the freeway one morning (lucky for me I noticed the gauge as this happened and was able to pull my foot off the throttle as the needle was clearing 22psi @ 4000rpm's. The car wasn't fully dialed in and I hadn't yet tuned for anything above 12psi; the tune was no where near ready to be boosting 20+psi. Reviewing the log showed a small knock spike of only 5 degrees. My water injection system truly paid for itself this day!).
A few days later, with the car running great except of coarse for the boost controller issue, out of no where the engine began to hesitate when boosting over 1psi. I immediately figured the problem boost leak related and likely to wined-up somewhere near the boost controller. My only concern at this time was how could a small vacuum hose, like the one's that run between the turbo j-pipe > Boost Controller > and Waste-gate, leak enough to cause the engine hesitation of a major boost leak.
NOTE: the fancy vacuum hose sold at your local auto parts store is garbage! You're better off purchasing the OEM-replacement vacuum hose they stock in the back room -- it'll last longer; I promise.
Solution: In order to fix both problems I replaced all the vacuum hose running between the turbo j-pipe > Boost Controller > and Waste-gate. This has thus far done the trick.
There must have been a small leak in one of the faulty vacuum hose I replaced at the boost controller because my last tune had idle 'air-flow-per-rev' dialed in at 25Hz (+/- 1Hz), and now the car idles around 28-29Hz. -- Looks like it's time for more tuning...
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