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microsquirt 940 crank angle settings

Melisa

New member
Joined
Jun 17, 2023
Im sure this has been posted before, but my search fu is lacking. I have a 93 940d with a microsquirt and 2nd hand yoshifab harness. I keep seeing where ignition is set to 90* after tooth #1. I keep getting no starts and back fires. Im running all stock b230ft except for a ipd cam and waste spark thru 4 ls coil, using the crank vr sensor. What am i doing wrong???
 
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Make sure your plug wires are in the correct order. Cyls 1 3 4 2 when the distributor rotor turns clockwise. If your disti has been removed since it was last running, make sure that it's aligned/installed on the correct tooth. With engine and cam at TDC #1 (both cam lobes up through oil cap hole), the tip of the disti rotor should be roughly over the notch/scribe line in the edge of the disti housing. This is #1 tower/plug.
Cam Lobes at TDC.jpgdisti alignment at #1 TDC.jpg
 
OK, go into MS Testmodes and test SparkA (you'll probably need to turn on the fuel pump first). Check that plugs 1&4 are firing. Repeat for SparkB, plugs 2&3. If these are backwards, change the A/B wiring on you quad coil.
 
Can you post a picture of your MS Ignition Settings? (Spark Output should be "Going High", Dwell of ~3.5ms, and Tooth #1 Angle of ~90deg.) How about a Tooth log during cranking?
 
Here's my settings.. my dwell is off I see that now.
 

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I don't have a timing light, that will have to wait till payday. I'm thinking somthings not hooked up right.. so I'm going to go back thru and double check my mess.
 
When I was setting up my speeduino and searched for what to use for the trigger angle, I found the answer to be 84 degrees and have tuned using this figure.
Am I to assume from the above that it should be 90 degrees?
My spark table does seem more advanced than others.
If I correct the trigger angle to 90 degrees, should I reduce the whole spark table by 6 degrees and start tuning again from there?
Will it make any difference if the overall effect is the same?
Tim
 
Every car/build is going to have the potential to be different. Set your trigger angle to your engine, not someone else’s.

Stop at a parts house and rent/borrow a timing light.

Use a timing light. Lock ignition timing using the ecu at 10 or 15*, adjust trigger angle until crank pulley/timing marks match. No need to guess, just do it correctly in the first place.
 
Every car/build is going to have the potential to be different. Set your trigger angle to your engine, not someone else’s.

Stop at a parts house and rent/borrow a timing light.

Use a timing light. Lock ignition timing using the ecu at 10 or 15*, adjust trigger angle until crank pulley/timing marks match. No need to guess, just do it correctly in the first place.
True, but I need to get it close enught to crank first.
 
Has the flywheel/flexplate been re-installed since the engine ran last?
Has the engine run since the cam was replaced? Have you double checked the timing belt? Beware, the crank pulley can shift on the rubber vibration damper and not read right. You can check that the cam alignment marks are good and a chopstick through #1 plug hole is at TDC.

I only said 90deg because that's close enough to start. The next step is a timing light to get exact timing - might shift a bit due to VR +/- connections and trigger edge selection.
 
If the 60-2 FW is installed correctly, the crank offset is 83-86° every single time.
To me it’s just one of those things, if you’re going to be setting up things like and ignition timing table, you should probably have a the knowledge, process and understanding of what is going on. It’s not like setting timing up by ear with a fixed curve dizzy. Not to mention that you never know what the last person did in there, and if you’re trying to be sure, go through the process.
 
To me it’s just one of those things, if you’re going to be setting up things like and ignition timing table, you should probably have a the knowledge, process and understanding of what is going on. It’s not like setting timing up by ear with a fixed curve dizzy. Not to mention that you never know what the last person did in there, and if you’re trying to be sure, go through the process.
Oh for sure, but if you don’t have a timing light and can’t verify the FW position the least I can do is say what is should be when everything is set up correctly :)
 
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