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Old 09-25-2009, 09:21 AM
GEE TEE GEE TEE is offline
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Join Date: Aug 2009
Cobra Make, Engine: Superformance 427R
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Quote:
Originally Posted by Got the Bug View Post
How long have you owned the motor? My recommendation would be to go back to the dealer that you bought the engine from and ask them to be your advocate in getting the issue resolved. This was a known problem on some motors several years ago and Roush ended up swapping out the carbs.
My engine is #180, built in 2005, it now has 13,500 miles. Since I'm the third owner of the car/engine I doubt Roush will help me out with the performance issues. In fact, I've contacted them twice asking for carb tuning specs (jets, power valves, diaphram springs) so I could verify my carb is as it came from Roush. So far, no response. There are lots of things I'd like to know about this engine (recommended plugs/gaps, timing, advance curve) but Roush is keeping quiet. I have eliminated my tip-in stumble through a coordinated attack on initial timing, advance curve, idle speed, idle mixture, and diaphram spring change. The jets and power valves should be OK based on the AFR plot on a recent dyno sheet I received with the car. The car is much more driveable now although it still won't idle below 1100RPM, and it bucks and complains if I ask it to cruise below 1800RPM. Maybe I'm just asking too much from an engine with a big (how big is Roush proprietary info) cam.
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