I couldnt find anything on missfiring or anything similar to my problem in any forum so here goes. I have a stock D16 in my 89 Si. The head gasket was just repaced with the heaad resurfaced. Im not sure if the was an exsisting problem on if it started after the head gasket was replaced. During ilde it wil idle normal but ever couple seconds theres a miss or stumble or hicup or something, the tach drops about a 100RPM but then goes back to normal idle. Then another hickup and so on. If i give it a small amout a gas just to raise the RPM i can still notice the hicup. Any ideas?? Timing, Injectors, something cloged?? Im gonna put up a video hopfully today to show whats up. Theres nothing else about missfiring here so any help would be apreceated! Thanks!

 

You could have a voltage problem, vacuum leak or your iacv could be going out. Check into those then let us know where you're at.

 

My tach goes all screwy when I accelerate and take the tach needle ove 3k. It sounds like geers slipping or water flowing behind my dash when the needle bounces. Do you think this and something to do with it also? If im getting a bad single from the ignition coil to the tach and with the missing could that be contributing to the same problem? Manbey it needs a new Ignition coil and distributor if it hase something to to with voltage. -40 with the windchill in Winnipeg today. Ill check thoes things you sugested tomorrow when i can get some heaters goin in the garage. Thanks

 

holy crap! is that -40F or -40C? had to ask, either way that's f-in COLD!

let us know how the initial diag goes!

 

sounds like the ignitor. when mine went out it made the tach go crazy and wouldnt start sometimes

 

-40c dude. extreem raisin pouch conditions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gvis420 &raquo;</TD></TR><TR><TD CLASS="quote"> water flowing behind my dash when the needle bounces. </TD></TR></TABLE>

Keep an eye on your coolant level. Make sure there is no air in there.

There is a possibly, the HG didn't seal 100% thus your losing compression into the cooling system. This would cause the bubbling noise behind the dash when you have your heater on and misfire.