Whats the SITC?

 

I'v been having a prob kind of like that for awhile now. But when i start to loose vac my car starts to misfire but at idle only. And i got a p0300 random/multiple cyl misfire. The car drives fine but just a goofy misfire. Sometimes it does it and sometimes it doesn't. At idle it will be at 20hg and then it might rise to 15 and then run bad. latley it's just been dropping to 17hg which for some cars is normal. I'v changed plugs,coil packs,maf the list goes on. It's also a lean misfire at idle. It got really bad and it would idle at 10inches of vac. So i did a boost leak test and found a few big leaks and it's helped out alot. Im going to do another test to se if i missed any. If any of your sensors were faulty you would most likely get a cel. If you were starving for fuel you would prob get alittle hesitation during accel/cruising. When your driving and you push in the clutch does your vac drop below 20hg to like 23/25hg and then level out at 20hg. Because if it isn't check for a vac or a boost leak because obvously those won't throw a code. When i had my big leak my boost really didn't come on much slower then normal. I don't if you wrote this or not but get a fuel press gauge (B@M are pretty cheap but good enough) and see what if your pressure changes when you loose vac or just see if it is were it's supposed to be. I did a comp test just to make sure i wasn't loosing vac due bad valves or anything internal. But yours doesn't sound like that. Also the oil from your airfilter can get in the maf and wreck the honeycomb part. But if you mess with that be very careful. Because if that got gunked up it can mess up your air fuel ratio bad. Well just suggestions, if you fix it make sure to comment.

 

Older unit. Apex'i Super Ignition Timing Controller.... essentially a manual timing controller, that looks like the old old old Super AFCs.