Is my idle too low

[MadsHilde]

Hey guys.

I had a problem with my car going very low in idle and wasn't very stable. I cleaned the, argh, don't know what it is called, the thing which you attach the CAI to, before the VAF. Part of the engine kinda. You spray the cleanser in the hole and use a toothbrush to clean. Guess you know what I mean. Anyways, it helped ALOT and my idle is again stable.
But I don't really know if it's still too low, this is a picture of my idle, what do you guys say, does it look normal?


http://img706.imageshack.us/img706/9328/01062011644.jpg

[PATDIESEL]

Stock idle for a manual K series motor is 750-1000 RPM (when the motor is warm, would be a tad higher when cold) so you are a tad low. Those revs keep the oil pressure decent so there is still some oil flow at idle.

[MadsHilde]

Hmm, so is it something I should look further into or will I do alright if I leave it be? I mean, I have no idea what the problem could be for the low idle, I'm a kinda newbie when it comes to the engine and pretty much everything else carstuff related, but I want to learn for sure.

[davmac]

If your idle is steady at what might be 600 - 700 rpm (from your pic) then I wouldn't touch a thing. The dashboard tach is a little hard to read at idle speeds. To really know your idle you'd have to hook up a tachometer to the diagnostic box under the hood (usually a tune up tachometer connects to battery for power and to ignition terminal on the diagnostic box). But, again - if you cleaned the throttle body and now your engine idles smoothly then let it be.

[mitmaks]

Stock idle for a manual K series motor is 750-1000 RPM (when the motor is warm, would be a tad higher when cold) so you are a tad low. Those revs keep the oil pressure decent so there is still some oil flow at idle.

It its right at that 650rpm mark then it's PERFECT. Stock should be 650 +/-100 rpm.

[MadsHilde]

Yeah, but mine is only taking around 450rpms as you can see on the picture, so I guess it is a bit low. But at least it is stable. Before, it could easily drop under the 250 mark. But I would like a couple of more rpms, don't know why it is a bit low.

[Daninski]

Set your TPS as well. In limp mode (TEN and Grd jumped) you set the idle to 650rpm then when you remove the jumper it will settle in at about 700. You can't go by the tach on the dash you need to use an external tach. When adjusting your idle turn the screw, top of TB in untill the car starts to stumble then out untill it hits 650. Don't adjust past this or your initial acceleration will suffer.

[MadsHilde]

Hey Daninski

Sorry, but this is kinda Latin to me: Set your TPS as well. In limp mode (TEN and Grd jumped) Would you car to explain, I very green.

Isn't it kinda cheating to just adjust my idle on the screw, what if it is something else that's at fault and causes my low idle?

[Inodoro Pereyra]

If your idle is stable, you don't have a CEL, and your car is responsive, everything is ok. You just need to adjust the idle.
First, start the car and get it up to operating temperature. Then turn it off.
There's a small diagnostic box in the engine compartment. Inside the box lid, you will see what each of the contacts is for. One of the contacts is labeled "TEn" (as in Test Engine). You need to connect that contact with a contact labeled "GND" (for GrouND), with a piece of wire, or a paper clip.
Then, connect a tachometer (do not trust the dashboard tach) as per its instructions.
Start the car again. Now, looking at the tach, adjust the idle speed screw, until you get the idle right. Adjust the screw no more than 1/4 turn at a time, and wait a moment for the idle to stabilize, before readjusting as needed. Make sure the cooling fan is off.
Then, turn the engine off, and take the jumper wire off the diagnostics box.
For testing the TPS (throttle position sensor), you will need a small socket (I think it's a 7mm, but I'm not sure), a multimeter, and 2 clothes pins.
Get the clothes pins, and stick one on the signal wire on the TPS (pink/green. 3rd from the left), and one on the ground wire (black/blue. First one on the left). Connect the multimeter between the 2 pins.
Turn the key to the "ON" position. You don't need to turn the car on.
With the throttle fully closed, you should read between 0.5V and 1V between the 2 pins. Then open the throttle completely. You should now have between 3.5V and 5V. If the voltages are out of those ranges, loosen the TPS, and adjust it, until you get the voltages right. Then, tighten the TPS, take the pins out, and you're done.

[MadsHilde]

Thanks a lot, Inodoro. I have got to try this out. I may not do it myself, afraid to do something wrong somehow. I'm not very good with electricity. But I may find someone who can help me.
Again, thanks for the post.

[Inodoro Pereyra]

Glad I could help.