I pulled my motor to do a clutch and coolant reroute, when I put it back together I've got a leftover connection and the car is idling at 4000rpms. I'm hoping they're related, ha. For the life of me I can't figure out where this thing goes. It T's off the other harnesses right at the back of the intake manifold. Any ideas?

 

looks like o2 connector.

 

YESSSS!! That's it, awesome. Thanks. I'm an idot.

 

fail.

 

Woohoo I recognized it as such too. My miata wrenching skills must be leveling up slowly.

 

Same here.

 

So now that that's out of the way, and I've already made an *** of myself... Any ideas on why the car could be idling at 4k?

This is with a MSPNP, on a '99 miata. The car was running fine on the MS and MAP sensor before the motor came out. All that changed was the motor coming out, new clutch going in, and turbo going on. Runs great at 4000rpms, throttle is closed, can't find any vacuum leaks.

 

Plug up the Idle motor?

 

That's in the front, by the throttle body!

 

Mad tyte vacuum leak yo!!!

 

homosexual vacuum leak

 

+1 on the idle air control make sure its all good.
Kris.

 

I've had a vacuum leak before and the thing idled at like 1500. This is seriously sitting at like 4300rpms. The Megasquirt is reading 30kpa. If it was a vacuum leak, I should be able to stick my head inside wherever it's leaking.

I unplugged the IAC and plugged it back in, it does the same thing with it plugged or not.

 

Disconnect that idle air control ************ like crazy yo and turn that bitchass idle screw **** down till your ******* engine dies. If it doesn't you have a mad tyte vacuum leak yo.

Also make sure your throttle cable is not too tight, pulling the throttle plate open.

 

Stop being a lazy *** **********-- it is a mad tyte idle leak yo because your engine needs air and fuel to run right? It needs a shitpile of air to run at that high of an RPM. Where is that air coming from? Hmm

 

Seriously man, like I said, the throttle is not open. I even took the charge pipes off to check it, it's closed. I've tried turning down the idle screw, doesn't do ****. The ECU and boost gauge are reading hella vacuum. When I had the motor out I did take the intake manifold off to put injectors in, I just find it hard to believe I screwed it up that bad. I'll pressure test it and be back in a few. Thanks for the advise.

 

Uh oh. I think I know what your problem may be.

if the throttle is closed/almost closed, and the idle screw does absolutely nothing, its GOT to be a leak at the manifold somewhere.

car can't possibly idle higher without more air.

 

Check for leaks around the injectors.

 

Brake booster hose, egr, or 1000 vacuum hoses.