Its a 2000 gt
It idles at 750, the. Jumps up to 1100 everyone in ahwhile.. is this normal? It has always done this. I do t feel any power loss or anything...

 

My 96 cobra had the same problem. I can't remember what the problem was lol. I'm thinking it was my heads

 

Uhohh....

 

Check your cold air intake mine did that last week when I changed the filters. Make sure all the hoses are tight and pushed all the way in.

 

Im almost sure it was my head gasket had a leak

 

Nothing I can do about that...

 

Head gasket or intake gasket? Generally a head gasket will produce coolant and/or oil leaks.

An Intake gasket will cause surging and its not to hard to diagnose, just spray some brake cleaner or something similar down around the mating surface of the intake and heads. If the idle changes while you are spraying then that will indicate a small vacuum leak in the gasket.

You can also do this for the throttlebody, plenum and any vacuum hoses.

Also check your MAF, if you've run a cotton gauze air filter with filtration oil that isn't MAF compatible it might have glazed the sensor.

 

There isn't any coolant or oil leaking... so ill check the intake gasket.. I have had the air filter changed since I've owned the car. Its just the jiffy lube brand though.

 

when is the last time your throttle body had a good cleaning?

 

Alright now that I am on my computer and can type a bit..
About 3 weeks ago, i took off the air intake and cleaned that out really good and also the MAF. I did that because of the odd idle.. When I originally posted this thread i went out and took a look to see if i can locate the source.. And low and behold the plastic tube thingy that conects to the heads (idk proper term. its a 2k gt) wasnt fully secured and had a slight leak. tightened that up and snugged up the groments. The rough idle still continued, I reset the battery, idk if that would help.. The weird thing is that if i start the car and dont move it or drive it, just simply start it, it will idle smooth as butter, no fluctuations.. it seemd to be when i really get onto it.. or even drive slightly aggresively. The thing is, its not crazy fluctuations, its like it idles at 750 then jumps to 1100 and stays there for a couple of seconds... I havent had the opportunity to use the carb cleaner to check for bad gaskets but will this weekend. I will also clean the throttle body/ plenum. kinda hopping for an easy fix/ or it be something that isnt hurting the engine... do not have the money on a 16yr olds budget for anything serious..

 

Take the TB off to clean it

 

Any tips? lol

 

there is a you tube vid out there as well as one at brenspeed.com at least I'm pretty sure theres one at brenspeed

 

Does your speedometer work correctly?

 

Yes sirrr. All guages read normally.

 

Ok. Whenever this happens what is the tempurature gauge at?

Vacuum leak is very possible.

Carb cleaner trick doesn't work as well as it used to anymore. The computers are tuned real finely when it comes to air fuel ratio. As soon as it sees the Carb cleaner at the o2 sensor it cuts the injectors back. Leaving almost no noticeable idle change... you need an obd2 reader that can monitor long term fuel trims to get a more noticeable reading with the Carb cleaner.

 

All guages are normal. I'm going yo clean the throttle body this weekend. Hopefully that does the trick.

 

It wont.

 

-_____- then what?

 

Well the best thing you can do is let me do a smoke test on your engine and look for leaks.

The reason it wont work: your vehicle is not equipped with an electronic throttle body. Therefore the engine idle is not controlled by it and it doesn't matter if its dirty