Trouble setting BISS

[TurboT91]

I have a very modifed '91 Talon TSi AWD 5spd. I am experiencing a weird problem when I ground out the plug behind the battery and the diagnostic port terminal so I can set my BISS. Any time I do this...I get idle surge and can not set the BISS to a steady RPM. Normally...I do not have idle surge. As a side note ...my blinkers recently went out. My flashers work...but the blinkers do not. I know there are a few things to check for this (bad wires...hazards switch) but any other suggestions are appreciated. I'm not sure if these two problems are related or not. It's weird...like when I gorund both locations for my BISS adj. it works in reverse.

Any suggestions...?

Thanks

 

[DJYoshaBYD]

1.. for your blinkers.. check the relay or the combo switch.. use a manual to test the pins on the switch, cause it may have gone bad...

2.. I would try to do a boost leak test.. you may have a small leak in the TB where it meets the IM... that is a common leak spot... a boost leak test will pretty much tell you if you are leaking any air..

next, check your IGN timing with the connectors grounded out... you may find that your IGN and your TPS is not adjusted right.. if you look in any manual, you have to adjust the TPS and the dizzy at the same time, then set the BISS...

and just for the hell of it, give the car a quick glance under the dash and hood, looking for broken/disconnected wires...

but it sounds like a small vac leak in the IM.. just try the boost leak test, just to make DOUBLY sure.. plus, even if its not the prob, you can still fix any leaks that you got...

 

[TurboT91]

I have done a boost leak test...no leaks. My TPS reads 10.5v at closed throttle per my logger. My base timing is set to 7* now but I also had the problem with the base timing at 5*. Like I said..it's weird. No idle (but car will die when coming off throttle to idle) surge untill I ground out the two locations to set my BISS screw. It's opposite of how it should be.

I thought about opening the dash/center console area and seeing if any wires got screwed up also....

 

[DJYoshaBYD]

that would be a good bet.. also, I believe there is an O-ring of some sort on the iacv... pull the idle motor off and check it for cracks, bad rings, etc... that might be the prob..

but how can you set your IGN timing correctly (you HAVE to set the base timing with the pins grounded) with the motor surging.. it would seem to me, that with the motor jumping rpms, you wouldnt be able to set the base timing right...

if your motor is surging with the connectors grounded, then there is no way you could see your correct base timing because the motors not idling steady enough for you to be able to set it where it needs to be..

start checking for wires..

 

[TurboT91]

I'm still able to set the timing because I only have to ground the plug behind the battery. I only get idle surge when both plugs (timing and diagnostic) are grounded together.