Ok, so out of no where my car developed a miss. Also when you quickly rev it up sounds like afterfiring, and basically running shitty. Things ive noticed, while idling the laptop shows the idle speed jumping around, but its very fast ie: its at 800rpm then it looks like 1800rpm. Also the timing on the screen appears to do the same thing ie: at idle its 8deg but while i stare at it seems to jump around to say 25deg. Ive changed the plugs, didnt do anything, heres the interesting part i put a test light on the neg side of the coil (leading or trailing) and when the engine misses my test light will almost go out. Then i put a inline spart testor, same thing when the engine missed you could see the spark go out. ive check various connections, and tried a new dist. Nothing so far, i tried searching for this problem but couldnt find ****. If anybody has any ideas id love to hear them.

thanks
mike

 

What kinda car?
If this is a Kouki FC, we've had headaches with the CAS plug, if you're still using the stock one.  Clean the pins and make sure they are plugged in snugly - make sure you feel the "click" when it engages.

If it's FD, we've seen the magnetic pick-up's fail for no reason.


-Ted

 

Thanks ted, i checked resistance on either side of the cas connector and its very good. Oh by the way its a FB with 88 turbo engine. Ive noticed the tach reading jumping around and the leading timing moving. When you rev it up at idle and hold it you notice as soon as the timing on the screen jumps the engine stumbles. I had the timing hooked up, but i since dissabled it again and seemed to make things better. Could this maybe related to a ground, if so is there a particular spot that you recommend putting one?

thanks
mike

 

What is your home and trigger sensativity set at?
I would set them at least to 3.
I doubt it's a ground, unless we're talking ECU ground?
The RPM display is dependent on the CAS input only.


-Ted

 

I have it set at 3, i emailed matt from haltech he said its not likely the computer but theyve had their fair share of electrical interferance causing this. He recommended moving everything away from the cas wires. Ill do that today and get back to ya.

mike

 

Good luck!

One last thing is you didn't ground the "front end" of the shielding from the ignition input wire group, right?


-Ted

 

Im confused, do you mean the braided wire that wraps the cas harness, or do you mean the ground on the haltech harness? anyway i tried rerouting the cas harness and drove the car but this time i dataloged, did the same damn thing. scrolling through the datalog out of no where the rpm goes to like 14900 then maybe 12200. Im back to scratching my head.

mike

 

Yeah, the ground that wraps the CAS wires.
Come to think of it, I don't even know how you got the CAS wires connected.
I usually use the stock wiring and tap into them on the back end by the ECU plug.
I have also eliminated all the stock wiring except for the plug and a few inches - this allows me to unplug the CAS very easily.
I have heard of people hardwiring the CAS directly into the Haltech wiring and throwing the plug away.
How did you do it?


-Ted

 

i used a 8inch piece off of the 88turbo harness, the i hard wirded that to the haltech. I did that for the same reason so i kept the factory plug allowing me to unplug the cas. Now that we know what ground were talking about, am i supposed to ground that or not? I currently dont have it grounded.

mike