very Frustrating cold stalling problem

[Crazyjoker77]

hopefully some of you dsmers can help me with my very annoying problem.

First off ill go threw what i have checked

-plugs are new and properly gapped at .28
-no boost leaks
-cleaned throttle body and ISC
-Tested ISC coils all are 30ohms
-tested TPM sensor its properly calibrated
-confirmed 5degrees timing

Now on to the story.

My throttle body shaft seals were leaking pretty badly (they where non existent) so i removed the throttle body and completely cleaned it and installed new shaft seals. As well i removed the ISC and tested its coils as well as cleaned it up also while i was in there i put a new Oring on the BISS but i never took note on its original position so this may be my problem?? Now when i removed the throttle body i lost quite a bit of coolant and didnt bother to replace it and accounted my problems to having insufficient coolant. But today i drained the coolant out(via popping off the lower rad hose) and filled it up with brand new mixed coolant.

Now when i start it up (coolant cap is off as im trying to bleed out any air in the system) I set the idle to 1800 right away (since i didn't know where it was previously and know it should idle at that on cold startup) the idle stays steady at that and the motor sounds healthy getting about 17-18"hg vacuum but after about 30sec to a min the car will just shut off like i turned the key off. if i turn the key it will fire right back up again but stall out again in another 30-1min. Also if i give it any gas over 3k it will stall as the rpms fall.

Now before when i was on the old coolant all problems would go away once i got it up to operating temperature (and believe it will be the same way now)

Also i have a logger and nothing looks out of the ordinary and no codes are popping up or stored in the ecu.

I never had stalling issues before i took the throttle body off only a few backfires and a loss in vacuum caused by the leak from the shaft seals.

All my mods are in my profile and i would greatly appreciate any comments or feedback on my situation as i would like to get this issue resolved.

Also if you would like me to perform any other tests or require any more info please feel free to ask.

 

[tbonitz301]

Sounds to me like the isc isnt lined up properly. You might try a couple different positions until you fix your problem.Try this first though http://www.dsmtuners.com/forums/newbie-forum/235871-need-help-adjusting-biss-screw.html

 

[Crazyjoker77]

Sounds to me like the isc isnt lined up properly. You might try a couple different positions until you fix your problem.Try this first though http://www.dsmtuners.com/forums/newbie-forum/235871-need-help-adjusting-biss-screw.html

what do you mean by "not lined up properly" are you talking about it not being at the correct step?

 

[tbonitz301]

Yes that is what im saying.

 

[Crazyjoker77]

but if that was the case would it not cause symptoms such as idle surge? My car idles very steady but just shuts down after a certain period of time and once warmed up the problem goes away.

 

[tbonitz301]

When the throttle is closed the isc is controlling your idle by letting air through. Im thinking that its off a step, and instead of idling cold around 1500 and dropping to 750 like normal it is closing completely after warm-up. Does that make senseWTF

 

[Crazyjoker77]

When the throttle is closed the isc is controlling your idle by letting air through. Im thinking that its off a step, and instead of idling cold around 1500 and dropping to 750 like normal it is closing completely after warm-up. Does that make senseWTF

but the thing is the coolant hasnt even hit 120degrees(as per my logger) yet opertaing temp is 195 and even if the ISC shut completly air is still bypassing the throttle plate via the BISS and prevent it from stalling.(also the fiav is not completly closed yet as the rpms still continues to drop as the car reaches operating temp)

Tommorow im gonna sit with it and keep starting it after it dies till it get up to operating temp and then play with the BISS some more.

 

[tbonitz301]

I see what your saying. Good idea. Any luck

 

[Crazyjoker77]

well folks i think i resolved the problem and had nothing to do with the throttlebody at all.

FOr my setup I'm running my Maf-t to compensate for my 680cc injectors and the SAFC for fine tuning. Therefor the setting on my safc should all be around 0.

Well since my shaft seals where leaking(badly) alot of extra unmetered air was being drawn in and not measured by the MAS causing a lean condition in vacuum(aka idle) and a rich condition in positive pressure(aka boost) Now when i was initially setting up my safc i noticed my fuel trims where way positive with the safc zeroed out (the ecu adding fuel because of lean condition caused by the extra unmetered air) I not knowing i had a vacuum leak compensated for this by adding fuel via the SAFC to get the proper fuel trims and O2 reading.

Now when i fixed the leaking seals i never thought of adjusting the safc and was adding alot of extra fuel eventually causing it to become so rich that it would stall out.

Now this is only my theory but it managed to idle all the way to operating temp and a quick 4 block cruise without any issues.

Looks like im spending the next week tuning again....