high idle when cold then settles

[mistagst]

ok guys so my friend bought his 1st dsm the only thing wrong with it that i can tell is that when you start it when cold it starts at 1500 then jumps to 2k and slowly goes down to 800 where it should be what could be the problem?

 

[XiKeiyaZI]

When the engine is first started and, especially when it is cold, it will sometimes increase the idle into the 1500-2000 range in order to achieve operating temperature quicker as well as help calculate and determine the needs of the denser, cooler air. This is common.

 

[AG 305]

When the engine is first started and, especially when it is cold, it will sometimes increase the idle into the 1500-2000 range in order to achieve operating temperature quicker as well as help calculate and determine the needs of the denser, cooler air. This is common.

THIS. but now if its bouncing from 1500 to 2k back to 1500 back and fourth it could be idle surge

 

[XiKeiyaZI]

THIS. but now if its bouncing from 1500 to 2k back to 1500 back and fourth it could be idle surge

Good catch. If it never settles and it bounces up and down, this is called Idle Surge, a fairly common issue and sadly one that plagues most DSMs.

 

[mistagst]

thanks guys! just thought it was a little weird the highest mine goes when cold is around 1300 but goes down to normal pretty quickly. his stays at 2000 for a while then slowly drops

 

[AG 305]

no prob! if the problem IS idle surge then check this out. it helped me alot with my issue also

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[galantlvr34]

It could also be a possible iac(idle air control valve) issue too.You can try taking it out and cleaning it.Do Not Use carb cleaner on it that is a common mistake people do.Take a dry clean rag and wipe the carbon build up off of it and wipe inside the throttle body where it sits.When is the last time the throttle body was cleaned out sometimes cleaning it will help.If that doesnt do anything it is normal and just the fiav warming the car up.

 

[mistagst]

dont know the last time it was cleaned its raining out now i will check asap tho thanks

 

[Tyeler18]

Does he have the A/C on or defrost on when he starts it? My MAF on my 3g is going out so if the motors cold and I start it with the A/C or defroster on it will idle really high and slow settle back down the 700.

 

[CrawlinZX14]

I have a similar issue. Mine will fire and sit about 2k on a cold start, then it sounds like a miss and drops to about 1500 for a few seconds as it builds back up to 2k. It will cycle like that until I hit minimal operating temp, then it will hold steady about 800r's. It started that after I adjusted the biss to bring the idle up from about 550rpm to 750-800rpm so it would not stall at a light in my auto talon. Any input as to what is causing my surge? Sorry to jack the OP thread about it, but similar in issue to mine.

And I have no def or ac on. AC has no belt on it for draw off the compressor, and I seldom use the heat yet..


OP your like 20 min from me too. I live near algonquin commons.

 

[Bouche Dag]

You should block off your FIAV. The plate is like 20 bucks or less.

When I start my car, I idle at 750 within 3 seconds.

 

[mistagst]

crawlin we should meet up sometime!

 

[CrawlinZX14]

crawlin we should meet up sometime!

Im normally around on weekends. If you have seen a fat guy on a retardedly loud blue ZX-14 around thats ###### me. HAHAHA PM me and we can set something up when I will be around.

You should block off your FIAV. The plate is like 20 bucks or less.

When I start my car, I idle at 750 within 3 seconds.

I just found the link earlier about this, so I am going to look into doing that next weekend more than likely. Going to run the car tonight for a bit and see how it does on my way to work before I really dig into it to deep.

 

[Bouche Dag]

I love having my FIAV blocked off.

Cold starting with a full 3in and having my car idle at 2k for ~2 minutes was embarrassing!!!

Should also note that there is a free FIAV block off mod you can do. It's floating around tuners somewhere.