2G Stuck RPM's

[Inkdlyfe]

So the other day I was driving my eclipse and out of no where the throttle seem to have gotten stuck or RPMS just rose on it own ? I would let go of the gas pedal and the rpms would ether rise 1k or stay at the rpms I was just at. It only does this randomly not all the time. Car starts fine idles fine all the good stuff untill you tap the gas it's like the injectors are just doing their own thing or something. No vacc leaks, stock injectors. Stock ecu. Etc. Issue just started out of no where. I check the TB nothing seems odd. What is causing this I thought it was my tune but even with out it it still does it

 

[BLACK'98DSM]

Your throttle cable could be getting stuck. Make sure it still moves smoothly. Otherwise this sounds like the possibility of a bad IAC.

 

[Inkdlyfe]

I was thinking iac too but its brand new, but I also got a cheap ebay one so that could be it.

 

[BLACK'98DSM]

A bad TPS could do something similar as well... Do you still have the stock TPS setup? If so, how old is it?

 

[Inkdlyfe]

The whole motor has a fresh rebuild the only thing I cheaped out on is the IAC, everything else is new. The tps is a oem tps from auto zone keep in mind I'm running 420a not 4g63

 

[BLACK'98DSM]

The whole motor has a fresh rebuild the only thing I cheaped out on is the IAC, everything else is new. The tps is a oem tps from auto zone keep in mind I'm running 420a not 4g63

Understood, so am I.

 

[Inkdlyfe]

So I'm looking at my scan tool right now , the TPS starts at 14.1% and only goes to 74.6% is that normal

 

[Inkdlyfe]

So I just took the car out for a spin around the block on the pass to the other side car ran fine good afr under boost etc, turnt around and otw back the throttle did that thing again. I would just tap the throttle and it would jump up to 3k hold it there for a second and I noticed the afr would jump to 10.0 and stay there and slowly lower. I am running e85 also.

 

[Vegas Smith]

My guess is some kind of throttle sticking issue.

 

[Inkdlyfe]

Ok so I think it's the iac. I unplugged it while the car was running , rpms spiked high, so I plugged it back it let it relax turnt the car off, unplugged the battery. Disconnected the iac put the battery back in and now it dont wanna idle duh but now it's not spiking. I adjusted the throttle cable so it's open about a dime thickness and now it seems to be fine. Not jumping any more.

 

[motomattx]

Easily verified by logging the tps.

 

[Inkdlyfe]

Tps is acting as should. I used a scan tool . Starts at 13.8% then goes to about 80% and drops like it should it dont get held or anything like the rpms would make it seem. Someone said its cause of a exhaust leak ?