So after about a month or so of playing with my MS I've tuned the fuel side of things pretty well. My idle is good, my AFR is dead on at all times, and I have the EGO correction to a maximum of 10%. I might even be able to run open loop at all times and I bet the mixture would still be reasonable.

Anyways, after a few hours of messing with the ignition side of things I got it to idle nice and I fixed the 600 to 1400 then back to 600 RPM idle issue. The car will drive around town quite smoothly. I start getting issues if I let it idle for too long, the ignition module will get very hot but when I start moving around it will cool off... Kind of weird, I figured the duty cycle would be higher with RPM's. If the module gets very hot it starts acting funny, and sometimes it will force the MS to reset, I'm not sure why it does this. Lee told me to set the dwell control to "Minimal for HEI4" which is what I'm using right now. By the way, I'm using 022i6 right now for my code.

Also, I'm getting some weird misfiring when I start to put a load on the engine, from around 60-80+ kPa. It's not RPM dependent, I can slowly rev it up to 7000 and it will be good and smooth.

One thing I've thought about doing is using a timing light to check to see if the timing is actually what it says it is, but I'm not quite sure how to go about it. Maybe set the timing to 0 degrees and point the light at the cam gears and watch the TDC notches when the light flashes? Any ideas?

Originally posted by ner947
So after about a month or so of playing with my MS I've tuned the fuel side of things pretty well. My idle is good, my AFR is dead on at all times, and I have the EGO correction to a maximum of 10%. I might even be able to run open loop at all times and I bet the mixture would still be reasonable. Anyways, after a few hours of messing with the ignition side of things I got it to idle nice and I fixed the 600 to 1400 then back to 600 RPM idle issue. The car will drive around town quite smoothly. I start getting issues if I let it idle for too long, the ignition module will get very hot but when I start moving around it will cool off... Kind of weird, I figured the duty cycle would be higher with RPM's. If the module gets very hot it starts acting funny, and sometimes it will force the MS to reset, I'm not sure why it does this. Lee told me to set the dwell control to "Minimal for HEI4" which is what I'm using right now. By the way, I'm using 022i6 right now for my code. Also, I'm getting some weird misfiring when I start to put a load on the engine, from around 60-80+ kPa. It's not RPM dependent, I can slowly rev it up to 7000 and it will be good and smooth. One thing I've thought about doing is using a timing light to check to see if the timing is actually what it says it is, but I'm not quite sure how to go about it. Maybe set the timing to 0 degrees and point the light at the cam gears and watch the TDC notches when the light flashes? Any ideas?

What did you do to resolve the idle rpm issue? Can you adjust your accel enrichment to get rid of the misfire? Maybe its dumping in too much, or not enough fuel. As for the timing, yeah you could set the advance to 0 for idle and then your cam gear marks should be even when the light flashes, but i dont know how well the motor will idle with 0 degrees advance..You can also use an adjustable advance timing light, the ones with a knob on the end of them, to set in a initial advance. So lets say you have your idle advance set to 10 BTDC, then you would set the dial on the timing light to 10 degrees, which will then light up the cam marks evenly, assuming your cam timing is accurate.

Except the cams spin at half crank :+

Yeah, but wouldn't I be able to see the timing marks still lining up half of the time?

Yeah it will still work since spark is firing twice on one complete cycle, but it will still flash on the TDC marks..I really wish we had timing marks on our lower timing belt covers, like the 4g63..I suppose if you had a degree wheel, you could make your own timing marks.

Originally posted by XtremeRS
What did you do to resolve the idle rpm issue? Can you adjust your accel enrichment to get rid of the misfire?

I resolved the ignition related idle issue by playing with my spark table for a while. I eventually came up with this for the idle area:


It still misfires a tad at idle, regardless if I'm using the stock ECU for ignition or not, so it's probably fuel related. If I run closed loop at idle attempting to maintain 14.7:1 it seems to misfire more, sometimes enough to get the CEL flashing. However, if I set it to open loop at idle which is about 14.0-14.7:1 the CEL will stop blinking and it will misfire a lot less. Kind of intersting. Right now I have the EGO correction disabled below 1200 RPM's.