idle problems again after change,please help

[94opalgt]

i had the problem figured out and the car was running fine.then,i read on here that we are not supposed to run vc breathers cuz it would make the car run lean cuz of the unmetered air.so i got rid of the breather and put a tfs oil spout on it and ran a hose to the intake tube like it was stock.now i have to rev the car up for a few minutes cuz it wont idle cold,surge and die.now if i rev it up after its warm when the idle drops back down it dies.now im thinkin it might not be getting enough air and i was thinkin about drilling a hole in the tb blade.is this a good idea?and how big of a hole should i drill?tps,iac,iat and maf are all ok.im trying to figure this out before i have to put it up for the winter.

 

[R.J.]

Try adjusting your idle like this:
'94-'95

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.

 

[a50sn95]

These are great instructionss on how to set the idle on our cars. My only issue with it is that I don't think it will SOLVE the problem on a car that has made some big changes to the intake path such as those listed in 94opalgt's signature.
I think he's moving alot more air at idle than stock, yet his computer is making calculations based on stock airflow. Specifically, there are tables for TB airflow, ISC neutral idle airflow, Dashpot Preposition, and so on. I had to make significant changes with my Tweecer to eliminate similar idle nd stalling issues, even after using a procedure similar to your to set idle. It appears to me that the processor is trying to cut down the airflow to the number in the tables, which causes the idle to fall, and then it see's that i's going to die, so it bumps up timing and opens the ISC to keep it running. This is the surging idle we all get. The Dashpot Preposion tell the computer how much air should run through the MAF when you let off the gas, which again is too low for his new setup, so it dies. I think he can eliminate most of it with some adjusting like you've described, but I'm not convinced he'll solve it without some sort of tune.

As far as drilling a hole in the TB blade, you don't need to do it. As R.J. described, our TB's have a provision in them that accomplishes the same thing. The idle bypass screw will do the same as a hole in the TB, and it's adjustable....
Finally, you should probably erase the Computer's memory, as you've changed the airflow through the MAF at idle, and it will take it a while to adjust for the new numbers. By erasing it, you remove the old adjustments, which my be causing issues now, and put the PCM in a "fast" learning mode.
I;d point you to some information on the Tweecer site, but it's down right now, so I can't.
Anyway, hope you find some sucess, it was my most frustrating part of driving my car until I got it worked out...

 

[94opalgt]

ok how do i erase the computers memory?is it just disconnecting the battery for like a half an hour?or is there something else i need to do?thanks for the help guys

 

[a50sn95]

Doh, sorry. I turn on the headlights, disconnect the battery, wait a few minutes (10 at most) and then hook it back up....

 

[94opalgt]

allright a50sn95,i'll give that a try.i hope this works.but can i ask a dumb ? why do i turn on the lights,what difference does it make?just curious.

 

[Methodical]

allright a50sn95,i'll give that a try.i hope this works.but can i ask a dumb ? why do i turn on the lights,what difference does it make?just curious.

Kills the residual power. Peace

 

[a50sn95]

yeah, there's a capacitor that keeps a little charge for the air bags after the keys are shut off (only lasts for a few seconds, I think). It just makes sure it drains it faster....

 

[R.J.]

The first time I used this procedure was on a 94 gt that had just done a TFS H/C/I, 75mm T-body, and 24lb injectors and matching maf. The car would not idle and would stall all the time. We tried every thing, this was the only thing that worked. The car idles like it is stock and never stalls. So I can't be sure it will work but I know for sure it was the only thing that worked on a car flowing more than stock air. good luck

 

[94opalgt]

allright rj and a50sn95,that little trick seems to be the ticket so far it idles fine and it dont stall when the rpm's drop back down after rev it up,thank god.im gonna take the car out tomorrow and see how it does on the street.you guys were a huge help,thanks.now i'll be keeping my fingers crossed and hope i dont get these problems again.thanks guys for all you help.

 

[95Cobra302]

Well i just bought and installed this nice ford racing oil cap breather, are u telling me it's not recommended and could give me problems!!

 

[R.J.]

I have that idle setting procedure saved on my computer and printed copies. It really works, I'm glad we could help.

 

[94opalgt]

well,i guess im gonna have to change what i wrote last night cuz i went to drive the car this morning and its still doing the same thing.the freaking thing will not idle at all,surge and die.that is pissin me off,im tempted to just put the breather back on the vc and run the car lean,at least it ran like that.you know what,im gonna try to pull the cap off the oil spout and start the car and see what happens.if it starts and idles then im putting the breather back on and saying screw it.im really fed up with this car right now.