- Apr 29, 2010
- 2
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I have a '98 Cobra with a 4.6L with a vortech V1 and built motor. I'm having issues with the idle sticking around 1,500-2,000rpm but it will seemingly randomly return to a normal idle sometimes. If I turn the car off and on it will idle normally when re-started and always idles normally when first started. This is also affecting off throttle deceleration (compression braking). It sometimes will compression brake until about 2,500rpm but then stop. Other times it will have compression braking at all rpm which is when it seems to idle normally when in neutral.
I adjusted the TPS from .8-1V and even swapped the TPS with another car but had the same issue. The IMRC has been removed and I cannot find any obvious vacuum leaks.
One possible problem could be that only 1 of the 2 discharge valves off the aftercooler go back to the intake while the other vents to the atmosphere since there is not a place for both on the intake. I have also heard the discharge valves can stick which could push boost back through the intake.
If anyone can help me I would truly appreciate it. I'm sure I left out some crucial information so please let me know what else you want to know. Thank you!
I adjusted the TPS from .8-1V and even swapped the TPS with another car but had the same issue. The IMRC has been removed and I cannot find any obvious vacuum leaks.
One possible problem could be that only 1 of the 2 discharge valves off the aftercooler go back to the intake while the other vents to the atmosphere since there is not a place for both on the intake. I have also heard the discharge valves can stick which could push boost back through the intake.
If anyone can help me I would truly appreciate it. I'm sure I left out some crucial information so please let me know what else you want to know. Thank you!