High idle when cold.

[nessy357]

I recently had to clean my throttle body due to a build up of gunk.Throttle is nice and smooth again, but when I start up when it's cold the revs go to 2000, and it hunts between 1200 and above till the engine gets to operating temp.

Any thoughts on what could be causing this.

Thanks Bob.

[94extreme]

any error codes? (ses light on?) maybe check and clean MAF.. all info can be found in the garage how-to section.

[mws]

Hmm... hunting only at idle when cold.

 

The first thing I would try is re-setting the ECU. Maybe it had been so gunky the ECU had modified its base map?

 

Disconnect the battery for 10 minutes to reset. This will set everything back to base maps.

[nessy357]

Thanks, no error codes come on.I disconnected the battery for 10 mins.

I noticed today that the revs stick momentarily after I shift. I also cleaned the throttle body with brake cleaner, I wonder if that's part of the problem?

Also checked the MAF, sparkling clean. Ireplaced the K&N filter with a paper one, thinking that might have caused the dirty throttle body.

[Slick]

i've been running K & N's for years and love them. try adjusting your throttle cable. my pathy revs at 1200 when cold. but after 5 mins she settles down.

if the revs hang up for a moment even after shifting then i would look more closely at throttle adjustment fer sure

[mattd123]

the ecu make the engine rev high when its cold to prevent it from stalling i have a 97 its done that since the day it was bought new in 97

[QuismO]

I also cleaned the throttle body with brake cleaner, I wonder if that's part of the problem?

very possible...you never know =P

[KILLVOX]

if the revs hang up for a moment even after shifting then i would look more closely at throttle adjustment fer sure 

 

What is involved with adjusting the throttle. I think im haveing a problem with the throttle. Or maybe its the tach. cable. Has any body had their tach. cable go bad.

[88pathoffroad]

No such thing as a tach cable, it's electrically driven.

[KILLVOX]

Thanks 88

[94extreme]

the ecu make the engine rev high when its cold to prevent it from stalling i have a 97 its done that since the day it was bought new in 97

but not 2000rpms. something ain't kosher for sure..

[The Drift]

I have this issue too. I actually get a bad squeal for about a 5 seconds though at startup everyonce in a while as well.

[94extreme]

I have this issue too. I actually get a bad squeal for about a 5 seconds though at startup everyonce in a while as well.

^^^ loose accessory belts.

[unccpathfinder]

my 87 when it had TBI and i believe my 95 does it but not as bad...but on cold mornings it has a warm up type code in the ecu or possibly something with that warm up flapper on the TBI engines (coming from a couple of mechanics i've talked to) i would crank up and idle at about 2500...and if i drove a lil bit and pulled up to a light shed go up and donw between 1500 and 2500 and then either i drove or it reached operating temp and it would drop back off to my 700 regular idle...

 

so if its doing what mine was/still do i believe thats normal...i'll find out in the AM if my 95 does it b/c its going to be kinda chilly

 

 

and doesnt nissan take a punch and hit the throttle adjustment screw so it cant be adjusted or should i say "shouldnt be adjusted" but i could be mistaken

Edited September 21, 2006 by unccpathfinder

[Electrifyliak]

My pathy has always revved high when starting in the cold, don't know the rpms because my tach's been out for quite a while. It always seemed pretty normal to me. Although cold here is like 0 degrees down to negative insane!

[unccpathfinder]

checked mine the past 2 days and at about 50 degrees which isnt really cold on my 95 she ran at 1500 for a while till it hit running temp then dropped back off to 700