Why is my idle erratic and the car sometimes die?

[85_305]

I am gonna try and put a LONG story short. My car stopped starting. I had to use ether to start it. It was a B*TCH to cold-start. But once the car was started in the morning, it only needed one small spray of ether everytime after to start. I thought the fuel pump was shot. Typical GM problem; fuel pump starts going, need ether to cold-start. Fuel SYSTEM is brand new. Take to mechanic, not the problem. Crank Position Sensor is shot. I have it replaced. They say that I still need ether to start, or need to disconnect TPS. They say TPS is shot. Car will never start on it's own. Well, one day it magically started starting on its own. Only problem is, until car is warm, then shut down and restarted right away, car idles at 3k RPM. Then, once warm car idles ok. Occaionally R's drop SUPER low, and car will randomly die when at redlight. Also, on occasion when you depress gas peddle (ALWAYS when cold, SOMETIMES when warm) the car will stutter, almost die, then take off. WTF is going on w/ my 3.1??
Thanks all, if you need further clarification please ask
Matt

EDIT: And if this makes one ounce of difference, the air box is NOT hooked up tight onto the intake. The clamp is missing, allowing a small air-leak.

[bszopi]

I'd check your IAC valve.

[85_305]

Where is the idle air control valve located on my GP? I am not very familiar with working on them..

[bszopi]

It is on top and to the right (?) on the TB. It is the valve that goes into the same place as all of the vacuum lines. Round can looking sensor.

[85_305]

Ok looks like a can an is located on the TB. What should i be checking for? How can I tell if it's shot or not?

[IsaacHayes]

Take it out and try cleaning it. It may be stuck/sticking. See if that helps first.

[85_305]

Ok. I will try this then let ya know what happened. Thanks!

[sil]

check the end of the pintle for wear, you will see a groove in it
if its worn, its bad, and chances are so is your tb

before you put it back in, check the distances, measure from the ears to the end of the pintle
if it exceeds 1 1/8 inch you can push down to get to 1 1/8 or 1 inch

reset your ecu, pull fuse or disconnect battery for 10 sec
do a idle relearn, http://60degreev6.com/showthread.php?t=25023

[85_305]

Is it possible this is my TPS that the mechanic "said" was shot?

[sil]

dunno, you can check it though, there are three wires going tot he tps
with the ingition in run(not starting the motor)
probe two of the wires(sorry cant remember colors)
check your manual for the specific car/engine
with tps closed should be somewheres around .5 volts
with tps fully open should be close to 5 volts
probe the wires, smoothly and slowly open the tps and check with your multi meter, make sure the voltage doesnt stop rising or doesnt spike out oddly

your manual will tell you the range your tps should read at closed
some cars its .47 some .78 is max
some manuals dont say shit
but if you have a tps with adjustable slots you can adjsut it, or elongate teh holes

i wouldnt piss around with adjusting the idle stop to adjsut the tps reading

[CNCguy]

How about the CTS (coolant temrature sensor)? A faulty CTS might signal that it's already warm and doesn't need the extra fuel for cold start and run. Isn't there a resistance test for the CTS?

[85_305]

dunno, you can check it though, there are three wires going tot he tps
with the ingition in run(not starting the motor)
probe two of the wires(sorry cant remember colors)
check your manual for the specific car/engine
with tps closed should be somewheres around .5 volts
with tps fully open should be close to 5 volts
probe the wires, smoothly and slowly open the tps and check with your multi meter, make sure the voltage doesnt stop rising or doesnt spike out oddly

your manual will tell you the range your tps should read at closed
some cars its .47 some .78 is max
some manuals dont say shit
but if you have a tps with adjustable slots you can adjsut it, or elongate teh holes

i wouldnt piss around with adjusting the idle stop to adjsut the tps reading

Well if it makes a difference, the day I picked the car up after having the CPS fixed and the mech. told me that the TPS is shot, the only way to start the car was to either disconnect the tps (then after it started plug it back in) or shoot ether into it. Then magically after a few days the car would start on it's own (wow what a Godsend lol). I dont have a multimeter; I will ask the Fiance's dad though. Thanks!

How about the CTS (coolant temrature sensor)? A faulty CTS might signal that it's already warm and doesn't need the extra fuel for cold start and run. Isn't there a resistance test for the CTS?

Now heres more fuel to add to the fire. Again, I dont know if this matters or not.. but ever since I had the CPS fixed the temp gauge reads, even when fully warmed, only slightly over 100* (dont remember exactly, but it's for DAMN sure not almost half way up the temp. gauge where it used to read!). I recently had the quick disconnect upper manifold coolant return line repaired, and wonder if something is going on??

The car DOES start by itself now, but it idles at 3k R's

[bszopi]

I think Marc might be on to something with the CTS. If you get ahold of that multimeter, check the resistance of it.

http://60degreev6.com/showthread.php?t=25015

If the temp outside is around 68ºF, then the resistance of the CTS (given that the engine hasn't been run for awhile) should be around 3.5Kohms.

[85_305]

I think Marc might be on to something with the CTS.

Ya think so? I am gonna call my Fiance's dad right now to see if he has one, though I'm sure he does. He's a MAJOR DYI'er and has vast knowledge. It's more like 0* here, but I will go by 32* and it should read about 9.5k-ohms. I will follow Sil's way of testing it. Thanks guys I will update you tomorrow probably.