Irritating problem that I cant fix....help!!!!

[captain]

Greetings everyone,
I just joined this club wrx.net...I mean like 2 minutes ago. Heres how my problem started...A few weeks back I went out to start the car, now this is Rochester
so its cold 6 months a year. Anyways I start the car and the idle goes to 2800, normal would be around 1700 cold and gradually work back down to 7-800.
Only this time it took forever to get back to 1200 so I started driving and I'm getting hesitation. From a stop , bringing the car to 4000 the rpms surge going to 4500 without giving gas. So It goes to VanBortel. They checked and cleaned the MAF, TPS, checked 02 sensors, checked for leaks, checked and cleaned throttle body still had the problem, so they decided it was the IAC valve and replaced it. All was good for 5 days and the hesitation, high idle and rpm surg was back. I decided to hook up the accessport and check the TPS. It should read zero when your off the gas , I take it out, reading zero cars running beautiful
then the tps jumps to 5-6 without any gas and it runs like **** instantly. So I put in a new throttle position sensor and it is still the same. It could run fine for 2 days or it could screw up 3 or 4 times a day. When it happens I have to reset the ECU which is getting to be a real pain. Any ideas other than what I've mentioned would be GREATLY appreciated.

[wrx1234]

Sucks, i can't really help you but the next question that someone is going to ask you is what year and mods do you have.

[captain]

Thanks for responding 05 WRX Cobb exhaust /Tuned

[jonsutton86]

Did you pull the ECU and check for burn spots, because your ECU could be going out

[captain]

No...didnt do that, hate to think that could be it. thanks for the response

[Monk_Knight]

I had a similar enough problem that I figured I'd share my experience.

I have an 03 WRX. Stage 2, was tuned with an Accessport. I changed the map from the base 91oct Stage 2 map to the ACN 91oct Stage 2 map without reflashing (the realtime update mode), and sometime fairly shortly after that I had a very strange issue with the car.

Almost immediately after starting the car, the engine would race like I had just floored the gas pedal. I'm talking immediate, rapid increase in engine speed... I immediately killed the engine before it hit redline, but it was going to. It acted EXACTLY like if I had turned on the car and then instantly pushed the gas pedal completely to the floor.

Freaked me out, so I had it towed to the dealership, they checked everything and insisted nothing was wrong. I pick up the car, stop to get groceries, and when I start it up again it does the same thing again.

At this point I was trying everything I could think of and the thought occurred to me that perhaps there was a bug in the Accessport that could have caused this. I reflashed the ECU (full reflash, not the realtime) and I never had the problem again. Shortly thereafter I got a protune and removed the Accessport altogether. It's been over a year now and I've never had the problem reoccur.

I'm not saying that the Accessport was the problem, but it started shortly after I started running a different realtime map than the one I had flashed, occurred several times in a short period of time, then never came up again after I reflashed the system.

I know it's a different problem then you are having, but I figured I'd share since you have an Accessport and a problem with the car thinking you are giving it gas when you aren't. Hope it helps in some way.

[captain]

Thanks Monk...any ideas at this point will help

[UEDan]

Check your cruise control cable and throttle cable for excess tension.
Its common for the cruise control to be too tight and temperature changes can cause the cable to expand/shrink.

Happened to me. Cruise control cable too tight.

[captain]

Thank you...I appreciate that...Never checked the cruise control...thanks