the ancient idle problem question

[300hpbound]

I know this is something that comes up a lot, but I hope that You all can help me a little.

If I come to a hard stop, it almost dies, then comes back up a floats around a little, then goes back to normal.

I read through the whole "Terry's Talon Troubleshooting" about 10 times.I have cleaned the Throttle Body and the EGR valve. I have checked the ISC, all four coils reading 32 Ohms (at cold).As far as I know, the O2 is fine, otherwise it would throw a check engine light (correct?). I've also checked all vacuum lines and haven't found anything. I was told that it could be the Idle Air Control Valve. could one of ya'll point it out to me, ### I can't find the damn thing. Or should I just replace the throttle body suspecting its the FIAV?

It's an auto 93 Talon Es

I checked around the other similar threads and none of them have the same info and problem

 

[Gstclipse69]

The o2 sensor wont throw a code.
You could just take the lower portion of the throttle body off and block the fiav passages. Its not that difficult to do and it would narrow the problem down.

 

[tbonitz301]

The idle air control is also known as the ISC. Really not sure what your problem could be though. How many miles are on it? Uhhh? The o2 sensor will throw a code. O2 sensor malfunction (bank1) (sensor1or2). The code looks like that, but im not saying that they always throw a code

 

[300hpbound]

I'm about to roll over to 112,000 miles. As far as blocking off the fiav, I don't know which passages that is. Plus wouldn't that mess with the idle more? It's got a pretty rough idle as it is

 

[tbonitz301]

Blocking the fiav is risky business if your searching for a good idle. Do a compression check for fun

 

[300hpbound]

Where do I rent out a compression check guage and hose? Autozone sells that kinda stuff right? The normal compression for a n/t 2.0L is around like 140-150 correct?

If there isn't any compression leak, any other suggestions?

 

[Gstclipse69]

The fiav helps keep the idle higher in cold temperatures to warm the car up quicker. Its also a cause of idle surge. If blocked, the idle in cold weather may be a little low at startup but should steady itself within moments.
I see that the o2 sensor does have a code now. Mine front o2 had 0.02v at wot with no cel. I guess you would need a logger of some sort to see the voltage to tell.

 

[tbonitz301]

It will be more than that. Our 2g turbo motors run 180psi. Thats low compression.N/A will surely be more. Do a search. im sure youll find something

 

[300hpbound]

I definitely don't have any access to a logger. There isn't any other way to test that bastard either when at wot huh? As far as I know, I can test it when it's just running though.

And as far as blocking off that passage, I don't think I want to do that. Just because i really don't want to take the throttle body off, nor do I want to screw with those passges just because aren't there smaller passages through them that take the coolant through em. And if any coolant goes where it shouldn't go, it's probably screwed. And i have no other means of transportation

I just looked in the book too and it says 2.0L non turbo is 192 psi (between 250-400 rpm). doesn't that mean it should be higher at my current idle?

 

[tbonitz301]

Not neccasarily. You do the compression check at cranking speed with the throttle wide open. You will need a friend to help so you can watch the gauge.Also watch how each cylinder builds pressure on each compression stroke.

 

[300hpbound]

I need to clearify a few things for myself. I thought that when you did a compression check, it was only cranking over the engine because the plugs are takin out.

i guess I'm just confused as to how to do a compression check. Obviously I need two people and a guage. I need to unplug something from the ignition so that it doesn't fire off and then I check each cylinder as its cranking right?

If it's only cranking then it can't be at wot otherwise it would flood wouldn't it?

 

[tbonitz301]

When you do the test take off the plug wires. remove one spark plug at a time and screw in the compression tester. Make sure your engine is at operating temp, and crank over the engine with the throttle wide open until the gauge no longer builds pressure. Also watch how each cylinder builds pressure.Hope that helps. It will not flood your engine

 

[300hpbound]

thanks Man, I'll definitely give that a try. if I do have a compression problem, how would that effect the idle? Also, If my timing is off, how would I go about checking that? I've been told that if the timing is off a couple teeth, it would mess it up

 

[tbonitz301]

Honestly man the most informative thing i could ever tell you is search,search,and search some more. You will find everything you could imagine. I like to call it the dsm encyclopedia