HELP PLEASE 97 Cobra wont hold an idle

[THE LIRA]

Hello all my name is Tony and I have a 97 Cobra that will not hold an idle in its own....
Here is the story:
we installed a new built motor and there is a little oil leak that I cannot find or identify. I did not put it on a lift because I have no access to one untill Friday but it is between the motor and tranny. The motor now has about 50 break in miles on it.

Idle problem #1 The car will turn on and then shut off right away. It will do this consistently it will not stay on one time and turn off the next. The idle seems rough and it goes down to about 300-400RPM and then off.

Idle problem #2 The other problem is when I push in the clutch and I am driving the car turns off not right away but it idles down to off. Like at a stoplight I will engage the clutch from second to put the brakes on and the car will shut off.

Here are some facts: it did have a little old gas in the tank that we could not get all the way out of the tank. We did put that Lucas gas treatment and 93 octane in it though. The car did sit for 15 months.

What could be the problem? PLEASE HELP she has been gone for 15 months and I need her running right she is my daily.

 

[98 svt]

Sounds to me like either the IAC or the MAF sensor is unplugged.

 

[THE LIRA]

IAC what is that? I know what MAF is but right now my brain is fried from all the college and putting the motor in the car this weekend.

 

[THE LIRA]

Idle Air control sorry I am am dumbass. I will clean the IAC and check the MAF.

 

[98 svt]

I'm saying that it sounds like one of them are actually UNPLUGGED, not dirty.

 

[STAMPEDE3]

Or the IAC is just FUBAR'ed.

 

[THE LIRA]

OK be right back......I checked both of them and they are plugged. I will check into the IAC thing tomorrow and get back to yall. Thanks for the tips I appreciate it.

 

[THE LIRA]

I cleaned the IAC and nothing I think I am going to replace the whole thing just to be sure. The MAF looked clean.

 

[hollywood43]

My IAC looked good on my '98 Cobra but the idle was very inconsistent. I changed it and all of my idle issues are gone. This was after cleaning my MAF with electrical cleaner, IAC with carb cleaner and checking my TPS voltage.

 

[hollywood43]

Double post. Website's real slow...

 

[96RagTop]

I would suggest cleaning your MAF anyways. Its a good maintinance thing to do. Its possible that it solves your problem too.

 

[98 svt]

Since the IAC or MAF snsor weren't found to be unplugged, my next guess would be a vacuum leak.

 

[THE LIRA]

I will check all the vaccum lines again and I already have a IAC inbound to pick up tomorrow morning. What is electrical cleaner?

 

[50 Proof]

I cleaned the IAC and nothing I think I am going to replace the whole thing just to be sure. The MAF looked clean.

if you IAC is no good and in need of replacing, cleaning it out will not make your car run better.

Try this, when you are sitting in the car at a standstill with the engine running, quickly turn the steering wheel clockwise and counterclockwise and watch what happens to the RPMs. If your IAC is bad, it wont be able to counter act the load from the power steering pump and your engine will either stall or the idle will start going up and down.

 

[THE LIRA]

I went to go try it and it does that. On the way to my barracks I got a check engine light that would be the O2 sensors correct?

 

[Red98CobraStang]

CEL (check engine light) could be anything. get the code read and report back.

My guess is a vaccum leak BTW and the CEL is going to be for a lean condition in both banks

 

[THE LIRA]

Could it just be an O2 sensor that went bad? They have been sitting there for 15 months. The reason that I had the motor rebuilt was because I got some water in the motor and there was some in the exhaust when we took out everything. Could that have fouled them out?

 

[STAMPEDE3]

Not likely, It will most likely be the IAC is bad or a Vacuum leak.

 

[50 Proof]

I went to go try it and it does that. On the way to my barracks I got a check engine light that would be the O2 sensors correct?

If your engine is stalling when you turn the steering wheel at at a standstill, that means your IAC is bad. Your IAC compensates for the engine load from the power steering pump. When your IAC is bad, it can no longer compensate and therefore your idle goes crazy or the engine stalls. If you have a vacuum leak, you'd more than likely hear some sort of hissing noise from under the hood. Go to NAPA, buy a new IAC, and let us know what happens. If you buy a new IAC and it still doesn't fix your problem, clean it out and return it.

 

[STAMPEDE3]

The A/C will also make the IAC idle up the car some.

From what you said about the car not wanting to stay running and when it does it is only 300-400RPMs and the killing when pushing in the clutch I say the IAC is bad.