Like the title says my revs keep jumping while idling from 2k to 2200 and will not rest at the normal RPM...before this happened I had changed my spark plugs and plug wires. Then I connect everything and start the car and this started to happen. I already checked the MAP sensor as every topic I pulled up while searching said. It's connected correctly. I'm not sure if there is something that I could've hit while under the car with the wrench getting the plugs out or what. Any help at all would be much appreiciated...plus I've already pulled off the UIM to check the rats nest and found nothing wrong there. I'm all out of ideas. Help a poor man out.

 

A couple of other things I've already done just in case these are what you think of...
checked the plug wires to make sure they are pushed in and in the correct location
made sure the plugs are all in the correct spot
reset the ecu
checked all the throttle cables and idle adjusters
Maybe if I threaten it with a piston...

 

Noone?

 

spray some carb cleaner at the lower intake manifold, Mine hunted like that, and it turned out to be my lower intake manifold gasket, it blew and the car got confused.

 

Not trying to deturb you from this suggestion albeit very effective, but I have seen an RX-7 catch on fire using carb cleaner as a leak detector. Just use some reserve.

Joe

 

Check your TPS. You may have knocked it out of position when you took the TB off.

Furthermore, not sure if this concerns you since it just started, but I had a hunting idle from 1000-1500, and I just finished replacing my LIM gasket yesterday, and it runs like a champ now.

 

I tried the compressed air trick and couldn't really find anything. I was thinking if I drove it to boost wouldn't a low boost mean there is definetely a vac leak? If the boost is ok then all is good with the vac lines and all that? I tried going under the car to find any sign of something that doesn't look right but all seems fine there. From what everyone tells me the spark plugs can't cause the idle to screw up so I guess the wires and plugs are out of the question. :-/ Man I miss driving my car.

 

Do what JamesVaughn3rd said and spray some carb cleaner on the LIM. You can just use some normal dish soap + water tho instead if you're worried about the fire hazard like what quicksilver_rx7 said

 

So today I start the car again to see how it's running and it drops to 1500RPM. Now from what I've noticed is that if I press the brake pedal down the RPM's will drop. Could my brake system be the culprit? Should I bleed air out of the brakes or see if there is some kinda leak in the vacuum line from the brakes? Don't know if anything else with the brakes could cause it but if anyone has any guesses.

 

Yes I do know that pressing on the brakes is suppose to eat a bit of RPM but 200? Also the power steering doesn't affect the idle at all. Wanna get to the bottom of this already.

 

Start with easy things such as checking for vacuum leaks...

 

same thing happened to me, I couldn't get my 1000cc primaries to seal right because they were so big. I sprayed some carb cleaner down into the "rats nest" and detected a leak. So it basically was a really big vac leak.

 

The thing is I just did my vac lines just in case it was a vac leak...that's why this is so frustrating. Some other things that might tip you guys to what's wrong...

-when revving at idle and letting off the gas there is a clicking noise
-when revving at idle and letting off the gas the rpm gos down to almost below 1k then back up to 1500
-when holding in the clutch the rpms go up a couple hundred

Thanks for all the tips so far guys.

 

Doesn't matter if you just did the vac lines. My vac lines are all silicone as well, and I still had a vacuum leak. You can have a vacuum leak at the lower intake manifold, or at the upper intake manifold, at the injectors, etc... just check it first.. one thing at a time..

 

Rechecked all the vacuum lines once again and still nothing. I did however unplug the electrical connector on the TPS to see how the car acted after that. If I revved the engine and let go of the gas the RPM wouldnt drop as fast and it didn't go to 1500RPM then back up and also no clicking noise. I don't know if this means anything. I'm just fresh out of ideas of what it could be.

 

You don't unplug the electrical connector ON the TPS. You want to take off the one sorta behind and under the UIM. That's the ISC.

 

Alright I know which one you are talking bout. Will try that after the car cools down a bit cause that was the first I was trying to go for but the manifold was scorching hot since it was just on and well Reno doesn't have the coolest weather.

 

Ok so I tried it and nothing changed. Ran exactly the same. Is this a bad thing or a good thing?