what is good or perfect idle speed

[VicBoost]

Hey, i just got my thorottle body cleaned up and the mechanic said he adjusted my thorttle cables as well. But anyways it runs around 1-1200 rpms @ a dead stop but when sometimes my car in a incline and i put it in park it goes around 2rpms. You think the mechanic put the cables too high or is this normal. Becuase i'am thinking of going back and tell him too make it a bit lower becuase at park its around 2rpm's. let me know what you guys think.

 

[02BLUR]

I like mine at about 1000rpm. I think 700rpm is what is stock, but I think its too low.

 

[femmeDSM]

Stock is 750, I believe -- at least it is on a 1g. Yours is definitely high -- I would alert the mechanic, or check it out myself if I was in your place.

 

[stars]

Yeah 2K is way too high. A heavily modified turbo vehicle needs around 850-1K idle it will probably vary according to which mods you have done. Just the air can hack will increase air flow so you have to bump up the idle a little to keep her from stalling. The mechanic probably binded the cables or adjusted them too much but you need to back that RPM down according to your mods. Once when you start changing factory settings its almost impossible to reset them back to specs unless you have a DRB scan tool or equivelant so watch how far he adjusts the BISS. Hopefully the mechanic removed the ICS before he sprayed TB cleaner. One only makes that costly mistake once =)

 

[VicBoost]

okay kool imma get it checked out.. btw it jumps really high when it on incline but when its level just 1200 rpm which i heard is good for cold weather like here.... but yea imma lower it too 1000. could i do this by myself and if i can how? any tutorials around here.

 

[stars]

Look for adjusting the BISS. Basic Idle Set Screw. You have to ground out the ECU then adjust the BISS to desired idle. Disconnect the ground you just made and restart the vehicle. You should now be set at your desired idle. Having a scan tool helps you put the idle on the right numbers. Just do a search there's tons of info.

 

[1LE]

750, +/- 50 is stock (for US spec, CA spec might be 50 higher IIRC?). Unless you've really gone crazy on the car, that's still fine. If you've got something like HKS 272/272 or VPC with 264/264 (or bigger), then 850 would be nice, but 750 is still OK. I can't imagine needing to go up to 1k unless you've got a fully built 9 second drag only car though

 

[VicBoost]

well now its back too normal guess it just took time too get use too i guess..

 

[tbob2985]

mine used to idle at around 700 i turned it up to 1-1200 also and it runs alot smoother when at a stop

 

[VicBoost]

same i think 750 too low i think should be over 1000 most other cars as well and the stop is much better.

 

[steve]

i think 750 too low

If the car is maintained and well tuned 750 RPM is fine. The only time you would need to raise it is if you have big cams.

Assuming you have a working ISC, changing the idle speed requires changing the ECU software. Normally the ECU will position the ISC to maintain 750. Getting it to idle higher requires driving the ISC fully closed before it will go up. Once you do that the ISC can't control the idle, can't emulate a dashpot, and can't hold the coasting idle up.

Steve

 

[VicBoost]

is it a bad thing if its around 1000-1200?

 

[knighteclipse1]

I have mine at 1000 rpm. Anything lower for me is too low and has alot of vibration since I had poly motor mounts and 3 inch exhaust installed at the same time. 750 rpm is factory setting.

 

[1LE]

If the car is maintained and well tuned 750 RPM is fine. The only time you would need to raise it is if you have big cams.

Just for a point of reference, my highly ported, no balance shaft, HKS cam'd, VPC motor purrs away very nicely at 750. I'd take an extra 100 though if I could get it because it will die if the rpms go under 550... And letting off the gas anywhere over the injector cut off point (which seems to be right around 1200 on mine) lets the rpms drop right to the borderline there before it recovers. Hence, the car will occasionally stall if I push the clutch in too early/while still moving too fast. It would only take 50-100 more rpms to eliminate that problem though, even with the VPC... With anything modern for fuel/air control I could probably get away with 750 with no problems whatsoever. What kind of setup are you guys running to need to bump all the way up to 1000rpms?

 

[bwhughey]

1G heads tend to flow more, and I have no experience with 2G equipment.

That said, my 1G has a ported head, 1mm oversize valves, HKS 264-I/272-E cams, and an aluminum flywheel. It will idle fine at 750, but lift-throttle stalling is a problem. So, I set the idle at 1000, which does help.

Regards,

Brad

 

[1LE]

1G heads tend to flow more, and I have no experience with 2G equipment.

That said, my 1G has a ported head, 1mm oversize valves, HKS 264-I/272-E cams, and an aluminum flywheel. It will idle fine at 750, but lift-throttle stalling is a problem. So, I set the idle at 1000, which does help.

I've got a 1g head too. JUN flywheel. Sounds like we're pretty close other than you've got a bigger cam on the E side, and I've got a huge hole in my intake called a VPC ;-)

What I'm curious about is when you added the flywheel. I'm wondering if a heavy flywheel prevents the lift-throttle stall due to more time to recover. The current flywheel on my car is really too light, revs drop faster than the gearbox is ready to accept the next gear under most conditions.