Idle not staying where i left it...BISS adjustment didnt cure-all

flubyux2 · Feb 17, 2002

ok, so after i got most of my other bugs worked out, i tried to re-set the idle.

lately its been idling high, in the range of 1400-1600 rpm, anytime, cold or hot.

cold start, for the first time of the day, will net me between 2000-2200 till she warms up a little, then itll go down to around 1500.

so, i grounded the ECU connector and the Idle Adj. connector near the battery, and the idle DROPS to 1000....wtf?

ok, so i wanted it a little lower, i go to turn the BISS in, and no resistance...wtf?

well i turned it in till the idle was set (i used this term loosely) at 850. i had a deep exhaust note, and the Pop in the exhaust (which i havent solved yet).

i checked, and the idle wasnt rock solid at 850, it was fluctuating +or - 50rpm.

alright, now im done. i disconnected the clip on the Idle adj. conn. behind the battery. the idle goes back UP, only to 1200 this time...wtf?

i take the grounding clip off the ECU conn. no change...wtf?

im befuddled, i was hoping it would stay at 850. but it didnt...wtf?

im guessing i need a new O-ring on my BISS and perhaps a new ISC, but id like a second opinion.

any input would be helpful,

thanks
chris

Edit: btw, should my O2 sensor be closed loop, and cycling between lean and rich, or should it be open loop and reading full lean?

yes, the MAF is fully hacked, no the BOV isnt vented, and there Are no vacc lines except bov,fpr, and boost guage.

flubyux2 · Feb 17, 2002

...just to clarify

the idle isnt SURGING, as explained in the VFAQ. its not surging between 1200 and 1500 2x per second.

its like it Surged, and wont come back down.

Before the BISS adjustment, it was at ~1500 closed loop

During the BISS adjustment, it was at ~850 open loop, full lean.

AFTER the BISS adjustment, it was UP at ~1200, closed loop (cycling)

tsi91at · Feb 17, 2002

Things I would check or try.

Biss o-ring: Put some vaseline around the o ring or grease. See if that temporarily seals it. It will dissolve from the heat so do that and that will tell you whether or not it's the ring before it melts. Just a little will do. If it's that go to my web page and the number of the o ring is on there. About 80 cents or so from hardware store. http://www.plymouthlaser.com/biss.htm

To check the ISC. Remove the 2 screws, the ISC and leave it plugged to the car. Set it in sight and turn the key on (don't crank). You should clearly see it go in and out with the key on and off. Screw doing it the Hayne's way. I have tried with a 6 volt battery on 3 different ISCs and doesn;t seem to work.

Check the cable slack to the throttle arm. That can be acting up. Nothing else give it some slack to make sure.

A leak down test of the turbo system may show a leak somewhere. It is tough to do if you do not have a compressor.

My page has some throttle body repairs on it.

Charles
http://www.plymouthlaser.com

flubyux2 · Feb 18, 2002

Thanks charles, now i just have to find some vaseline.

i do have a spare ISC, which has been tested. all the coils read 39 ohms, and the servo clicks in and out when i apply power to the coils and release it. ill just try to swap this one w/ the suspect coil thats on the car now.

i wont be able to do a leak test of the intake system for a while yet, i wont have the car home near a heated garage or power tools or air compressor for at least a weak. so that test will have to wait.

i read Terry's page and the VFAQ on the surging and ISC's, and Biss's and all that good stuff. i just like to go about things w/ a plan of attack rather than jumping headlong into it and throwin money and parts around, know what i mean?

thanks
chris

tsi91at · Feb 18, 2002

Hey,

A heated garage is nice to have. I have a space heater that I use but is small. Also, I get in a crank upthe car (if I can) take a spin. Get it good and hot, then pull in, open hood and shut the doors. I of course shut it off first

. Those engines generate gooooood heat.

The compressor was a great investment. 300 bucks from Sears. 160 PSI 30 gallon. Should last a few years (hopefully). I love being able to fill the tires w/o lines or freezing outside. :snowman:

A plan of attack is anything related to the intake system....The ohmeter is great to check everything TBody related and all sensors. It stinks to have to do but is part of owning these cars. I have to say most of what's on my page I did to the FWD AT and it will smoke a lot of cars even with the 13G (it is ported)... The Key factor is the tuning (and some money)

I would go ahead and get the O-Ring when you get a chance. Small investment and they are at Home Depot, Lowes, Sears and so on.....

Good luck
Charles
http://www.plymouthlaser.com

flubyux2 · Feb 18, 2002

yea, my friend who has a Talon, has a heated garage. an ACTUAL furnace in it w/ a thermostat, lucky punk.

i have a 1 car garage w/ a space heater too. bareley enough room for the car cuz tehres soo many tools, spare parts, supplies and shelves.

my problem is being away at college! it sucks to know that you have ALL the right tools waiting at home and you are Not there. i dont even know how much $$$ i have saved by doing all my own work, starting when i was 15, and now im 20.

anyhow, ill see about switing my ISC when i am in the same town as the car. hopefully that will drop the idle down.

what does the Talon use for a Cold start circuit? could this be sticking and causing it to run fast all the time?

thanks
chris

btw, i might have a ported and clipped 14b up for sale in the future, interested?

tsi91at · Feb 18, 2002

Good question.

I have yet figure out the cold start circuit. I figured it was controlled by the ECU or something???... I know the coolant lines pass through to help warm it, but many agree this is unecessary.

I have a 14B in the 93 that WILL get switched out (dont know what yet , but big). When I do I may or may not put it in the FWD. The spool on the 13G is unbelievable and not too bad high end either. I also have extra injectors (450cc) and a manual ECU if I do decide to upgrade it. So far, there is no need (67K miles on car). Clipped would not be good on an automatic do to lag.

My garge is one car also. I feel your pain. I trip over stuff and squeeze through it. I guess better than nothing.....Once I get married (june) we are house shopping. I need a 2 car garage (at least).

Charles
http://www.plymouthlaser.com

flubyux2 · Feb 18, 2002

you think the coolant lines going to the TB have anything to do w/ the FIAV?

my car is very hacked, im still discovering new mods every time i work on it. yesterday, i found out that i have 95+ pistons... go figure.

anyhow, i wouldnt be surprised to see the FIAV blocked off w/ RTV and the coolant lines gone.

i didnt NOTICE any coolant lines, per se. but i wasnt looking either. ill look when i change the ISC and O ring. what should i look for?

chris

tsi91at · Feb 18, 2002

Hey,

There should be two coolant lines that go into the bottom of the TB by the ISC.... I have some pics here http://www.plymouthlaser.com/tbor.htm

Hard to make out but may give you an idea. I left mine alone. I did change the hoses though. One of them (closest to the intake) always gets bad first and starts leaking.

I may block 'em eventually.

Charles
http://www.plymouthlaser.com

Idle not staying where i left it...BISS adjustment didnt cure-all

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