Okay so, I just recently picked up an 88 GXL. it wouldnt start before, so i popped in some fresh gas and a new battery and BAM. powered up. it ram super shitty and had no power so i drove it around more and floored it and it did something happened and all of a sudden it had power like my other car!

So, after that things seemed to have settled. i did a steam clean, didnt change much so i changed the oil as everyone says. so now im stuck with a crazy *** idle, BUT! it runs!

here is a video of it running, maybe by the way its running you guys can tell me what it may be.

http://www.youtube.com/watch?v=nnE2G3XYlfw

 

Try to set your Tps.

 

that screw u used to rev it back it out my car was doing that also. on the top of the intake manifold that screw thats in the middle use that to adjust the idle that other 1 seems to make it do what urs is doing

 

the lowest idle i can get is if it is allllll of the way in. not anywhere near my other car. just keeps going up. and the idle screw is all of the way down.

 

u need to back them out then just use the top 1 it also sounds like ur car is awfully loud upfront maybe ur o2 sensor is dicked or ur tps is bad

 

Are all the accessory items in the off position when this occurs. Set the TPS to one volt. Also, place a piece of tape on your Variable Resistor and place a mark on the tape that corresponds with how the screw is currently set and then jumper the initial set coupler and start the car and slowly adjust the Resistor until it stops reving if at all. If this adjustment process does not work then adjust it back to how you had it set previously and remember to remove the jumper wire.

 

i adjusted the TPS all the way out and it did nothing really. it went higher for the most part, but if i take the whole assembly and move it by hand as if i were closing the intake it goes down considerably, not quite an idle though. what are the odds of it being the BAC valve? i know that thing can cause some crazyness to happen.

OH! the other weird thing is if you push the clutch in the RPMs go up. let it out and they go back down to its "current idle"

 

You're supposed to adjust the TPS to 1 volt when engine is fully warmed up as doing otherwise is self defeating. If you pulled the plug off of the BAC when idling and the RPM drops that would tell you something or taking a pair of needle nosed pliers and gently squeezing the air tube connected to the BAC while the car is idling and if it were to drop the RPM that again would tell you something. Did you try adjusting the air adjust screw on top of the throttle body w/the initial set coupler jumpered and engine idling and fully warmed up?

 

not sure what you mean by the initial set coupler jumper thing. i have tried adjusting the idle air screw on top of the TB and i have to keep it alllll the way in to get it as low as possible.

 

It's a two wire green plug located by the leading coil which is required to be jumpered to adjust the air adjust screw on top of the throttle body in addition to setting the Variable resistor. Not doing so will cause the BAC to offset any adjustment you try to make and make adjusting the idle a futile attempt.

 

Really? Because my other car I can adjust my idle and it goes up and down by the screw. How do I set the tps to one volt? Unplug it and hook it up to a volt meter and spin it until it's 1?

 

I'm familiar with S4's. I'm sure the BAC will interfere w/adjusting the idle when the air adjust screw is taken into account if the coupler is not jumpered and the reason for jumpering the coupler is it cuts the duty cycle of the BAC to where it doesn't factor into offsetting changes made to the air adjust screw. To adjust the TPS the car needs to be fully warmed up. A multimeter set to DC volts is used along with a screwdriver. The TPS plug has a Green/Red wire which is where the red meter terminal is inserted and the black meter terminal is applied to a known ground like the negative battery terminal (do not disconnect the TPS plug when setting it). This could be done w/the car running and all accessories turned off, but again, the car needs to be fully warmed up. There is a screw located in the throttle linkage by the TPS which is surrounded by a spring and this screw is adjusted to where the meter reads 1 volt. Careful of applying any downward pressure to the screw when adjusting as it will affect the voltage output reading. Then jumper the initial set coupler to adjust the screw on top of the throttle body and remove jumper wire after adjustment and then go back to reading the TPS one more time to make sure it is still one volt and if not fine tune one more time.

If your idle is still too high/bumpy either the Variable resistor is in need of adjustment, thermowax is not fully disengaging from the roller cam, there is a vacuum leak, throttle cable is too tight, or primary throttle plates are opened too much and in need of adjustment or a combination of the above.

 

your secondary throttle plates are cracked open mine did the same thing it comes lose and opens the secondary plate a little

 

So I cleaned my BAC valve today. Got it back in the car and had a bit of an issue. The car wont stay running at all now. The only thing I can think of is the fact that there is air in those coolant hoses and its choking it for some reason..besides that i'm stumped...

Actually I just had a thought! cleaning the BAC valve may have fixed my issue...I need to readjust my TPS now to keep it running. Is that plausible? I currently have the TPS screwed pretty far in.

 

Air in the coolant hose doesn't affect the BAC, and as far as out friend the TPS, it needs to be set to 1 volt. There are no exceptions.

 

How do I set it to 1v?

-Warm up engine
-Shut down?
-Unplug and plug in ohm meter?
-Screw in or out till 1v?

 

TPS is to be plugged in when setting to 1 volt. Green/Red wire gets the red volt meter terminal with the black terminal going to ground such as the alternator housing or negative battery terminal. When you look at the voltage reading of the meter and turn the screw you'll know whether you're going in the right direction or not. When it's set to one volt as you move the throttle linkage to where it doesn't come in contact with the TPS any more the voltage should be 5 volts (TPS is fully extended).

 

Do I need to splice the wire casing to get to the green/red wire then? just making sure i'm doing this properly..

 

The plug to the TPS is less than a foot from the sensor so just back probe the plug to the TPS. Shove the red meter lead firmly into the back of G/R.

 

ohhhhh....thank you! I still feel somewhat new to the car. I appreciate your help, and speedy responses!

 

**** wrong thread....

(note to self don't drink and forum browse)