UPDATED 11/03/05 at 9:20AM EST

 

After having the throttle body cleaned by my mechanic to correct a hesitation and low idle issue, my 99 legacy 2.2L almost immediately threw the CEL Check engine light. At this point the hesitation did go away but the low idle did not. For the next 600 miles, the CEL came on 3 times. There were no driving problems until the last CEL. It stalled and when I started it, it was shaking the crazy, it drove home at 40 mph but with a huge lack of power. So I took it back to the mechanics. The only code in there was P1507 Idle control system malfunction (fail safe). The car has 68k. When I say low idle, its only when its warm and at 500rpm or below.

 

To correct the issue my mechanic:

Cleaned EGR

Cleaned mass air flow sensor

Reset ECU

Seafoam, half in engine, half in fuel

New OEM PVC valve

Checking the electrical contact on the idle control vale and applyed di-electric grease

 

Other maintenance within the last year:

Fram Air Hog air filter

Fuel filter (not OEM, its prob a piece of ****)

Trans filter/fluid change

Bosch platinum plugs even though I hear NGK is preferred

Running Mobile 1 for the past 50k or so

 

Heres the problem:

At this point I have picked the car up and drove it 10 miles. The engine and acceleration is much smoother but the idle is still low, in fact now it is more consistent with being low. Seems to be 500 and below. Sometimes its only 1 line above 0. This causes a very rough idle and nearly stalls out.

 

What do I do?

The idle control valve is $300, clean it maybe? Is there a way to adject the idle slightly higher to about 750 where is should be?

It takes time to get answers, We all dont know everything, and we may be doing somthing else to jump on a thread too fast.

Also the site has been acting odd of late. not every posting has answeres.

 

 

nipper

SO from what ive seen nothing major here aside from cleaning the MAF sensor and the throttle body cleaning. Whats is your complaint right now? a rough idle? Lok around and make sure there are nor loose or cracked vacume hoses.

There is no fail safe, there is closed lop and open loop operation. Open lop means that some of the sensors that tell the computer everythig is of is not in its proper tempertiutre or postion. These are if im corect are the 02 sensors, the TPS sensor and engine temp sensor.

You can get an IAC malfunction due to a bad vacume line. Its not unheard of for even the best mechanic or best of us to leave off a vacum hose. MAF sensors are delicate things and sometimes dont take well to cleaning.

 

nipper

some problems are so complex that people hesitate to even try to guess,and thats most likely your lack of opinions,hang in there. ed

Posting here as well as the new thread you started. Probably one reason you have not gotten replies is that you have already covered most of the things that we would have recomended. You have cleaned the IAC, but have you checked it for function? It may have simply failed, and is in need of replacement.

I see I wasnt exactly clear what the problem I am complaining of exactly is. Well its 2 things - the low idle, and CEL. I know the CEL is just a light but when its on I dont feel like im i n a reliable car that is properly maintained. The last time the CEL came on the car started shaking horribly and was almost undrivable - I wasnt sure if I was going to make it home when it did this.

 

The mechanic did check for vaccum leaks - finding none

 

I will be picking the car up today and will post an update

 

Thanks for the feedback!

I just got my car back. Its smoother than its ever been. Especially when accellerating. The idle is still very low in my opinion. It is on th line above 0 or a hair above it. This is def too low. Is this normal when the car is warmed up?

 

I would appriciate any help

I think your idle is fine. Don't quote me on this but I think the idle is supposed to be somewhere around 700 rpm's. The tach. probably isn't terribly acuurate at the lower end of the gauge so if the car idles steady it is probably good.

 

Did the mechanic check to see what the CEL was all about?

Did you ask the shop what they did to fix this? It would be nice to know what they did.

 

If you are saying that the idle is between 0 and 1000 rpm it is a little low. As was mentioned, 700 RPM would be about right.