i have a needswing intake. Just tried new maf sensor to no avail. Idling at around 1900 rpms. My next guess is the used 74mm throttle body I installed a year ago just went bad?

 

Can you install the original throttle body if you still have it?
If the problem persists you can discount the TB as being the problem.

 

any new updates regarding this?

 

If you have a fast idle, you have, almost always, a problem with the Throttle body. And TB issues can manifest in several varied symptoms.
Back some 4-5 years ago, Tricia from Oakwood GA was having all sorts of fast idle and round running issues with the car. Several visits to the local "German Auto Garage" cost her several hundred dollars, but they didn't fix the car.

Charlie Schmidt got tired of hearing her struggles and drove over to her house one day. He started swapping parts between her car and his. When he swapped the TB, the issues moved to his car.

As to the MAF, remember (in our cars) it does two things:
IT measures the amount of air flowing to the intake of the throttle body.
It measures the temperature of the air flowing to the intake of the throttle body.

The Throttle Body is the butterfly that regulates how much air is flowing and there is feedback from the TB to the ECU telling the ECU what position it is in, that is, if it is responding as commanded by the ECU.

If either item fails, the ECU has incorrect information on what is going on with the engine. Dirty MAFs do cause issues related to the fact that it can't tell accurately how much air is flowing and perhaps the temperature of that air. But from what I've observed over the years I've been here (since 2009), it seems like dirty MAFs can cause rough idle/running and that TBs are what cause idle speeds to go haywire.

Also, big vaccum leaks will cause idle speeds to vary and the engine to idle rough, but run at high throttle settings, usually, pretty well.

 

I was in this thread a couple of years ago because my idle was high and it got so bad I could idle down the street at 30+ mph! I replaced the TB with a used one from someone on here who had swapped his out and the problems went away... until recently. Now I have similar idle issues although not as bad. Currently, the idle stays high (around 1,500 rpm) as I roll to a stop but it comes down to normal idle after a few seconds. So, it seems to "know" that I've come to a stop and then it recovers.

@pizzaguy , does that description still match a TB problem? Why does it recover after come to a stop? Now that I type this, I wonder what it will do if I depress the clutch and coast down a hill. It could be a time thing that has nothing to do with stopping. Huh.

 

Let me check one thing, tomorrow, before I offer an answer to that question.
I think I can duplicate your symptom with my car and get an idea as to "yes" or "no.

 

Thanks!

I verified that the high idle (~1,500 rpm) with the clutch in continues as long as I'm rolling. It doesn't drop back to normal until a couple of seconds after I come to a stop.

 

Today did not go like I wanted it to. I'll drive my car tomorrow and test something and post here. I think you gotta be careful here, cause the car, the manuals, do idle higher if the car is coasting, but I'm not sure how much faster than normal, but I have noticed it.

You can only test idle speed when stationary It is, I think, a poor attempt at avoiding a "lurch" when engaging the clutch as you coast.

 

my issue is opposite... I am running rich long term....having lower idles when is drive & stopped at a red light. 500 rpms, almost stalling out.
park or neutral is ok......2005 limited roadster 130k.... many parts cleaned and swapped

 

This has just started happening to me. I had to open the intake manifold for the change over hose. I did not remove the throttle body. Just cleaned it. I am going to try and do the manual throttle relearn. If not then I need to get another m113 throttle body.

 

Any codes? You couldl be chasing a vac leak. See is you can find someone with a good OBDII reader, might help.


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