Intermitent misfires

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442olds
MegaSquirt Newbie
Posts: 5
Joined: Sat Jul 03, 2004 4:02 pm

Intermitent misfires

Post by 442olds »

Currently I am just running the ignition side of the ms2 on my engine. I have an msd distributor feeding a vr signal right into the ms2 v3 and then it fires a msd 6a and the hvc2 coil.

Today I have been working on my timing maps trying to get something that will allow the engine to rev past 6000 r's. So far so good, but I'm still not past that point. :( But that's not really an issue right now.

This morning i was running with a laptop hooked up and logging. This evening I'm running without the laptop. And every so often in a very intermitent pattern I will feel the engine cut out for a split second and then go along it merry way. This seems to only happen when crusining at a constant speed. highway speeds which tach out around or above 2500 seem to not be affected either. Or at least i don't feel the cutout as bad there.

Any suggestions?

The other problem I'm having is hot restart, with a short period between shut down and restarts (approximately 10minutes or less). Sometimes it will fire and start running but it feels like the computer isn't putting any timing into the engine. other times it just backfires, pops out the exhaust or makes the magic white smoke come out of the carb. I currently have my intial timing set to 0 degrees, and watching the logs I'm thinking that this is not a very wise decision. I'm thinking about setting it to 10 degrees advanced that way there is already some timing for the motor to start with rather than the interpolation between 0deg@r's and 15 deg@600r's. On a side note, with the engine setup with the mechaical distributor, I couldn't have any less than 10 degrees intial, or the motor wouldn't start. Which is why I think I should have at least 10 built in, it was just easier to do all zeros intially.

Any help would be greatly appreciated.

http://www.et-motorsports.cc/project_ca ... /index.htm
Clifton
MegaSquirt Newbie
Posts: 33
Joined: Tue Aug 02, 2005 7:25 am

Post by Clifton »

I have both problems. The hot start. I crank for a couple of seconds and then WOT (past 70%) to clear. Only way mine will start hot.

As for the miss, exact same thing. Mines a pulse width spike. I have a post here. http://www.msefi.com/viewtopic.php?p=138429#138429
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