Ignition Knock at start up
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Ignition Knock at start up
A good 95% of the time a have a Preignition Knock at start up on a warm engine. It occurs only at the transition from crank to run. I can see the resulted RPM and Ignition timing drop in the attached MSLs. I have attached two MSLs and one MSQ. MSL 5.1 121109 has the cranking trigger set to trigger rise (still knocks). MSL 5.1 calculated 121209 has the cranking trigger set to calculated which also gives a knock at the crank to run transition. I have researched what I can to solve this problem - any guidance/recommendations?
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48 Chev Pick Up, 455 Olds Motor, MSII V3, MSD Ign, TunerStudio MS, Emb Code V2.920, LC1 WB, VR with 36-1 Wheel
Re: Ignition Knock at start up
You can try decreasing table spark advance in the rpm, map region where the knock occurs. You could also try richening the after start enrichment.