The other day I took the evo out for a drive everything was fine up until after a second gear pull. After the pull I noticed when I completely let off the throttle and get back into the throttle (shifting gears) the car would sputter and go completely lean for a couple seconds then drive fine. Also noticed when I try to blip the throttle to rev it up there's a delay before the engine revs up. The car also runs more lean at idle. Today when I started the car it would idle for a little bit, abnormally at that (sounding) and then just shut off. It would keep doing this until the engine is warm. Another thing I forgot to mention is that I could also go WOT and everything seems fine as far as how it pulls and AFR's. I checked over vacuum lines, injectors, harness', ect and everything looked like the way it's suppose to. Any help would be appreciated.

 

Check the fuel pressure boost/vacuum line. Then check to make sure you didn't pop off an intercooler pipe. Is the AFR gauge reading normally?

 

I did check the lines for the FPR. All vacuum lines are in tact. Intercooler pipes are all on good. The gauge is reading fine no problems with that. It doesn't read abnormal. I'm starting to think it could be a tps sensor but have you ever heard of those going bad? Thanks for the help Dave.

 

Yes, could be TPS, may have just come unclipped. Hook up the laptop and take a look.

 

When I had my TPS go bad a while ago, it would idle very, very low and then cut off unless I gave the car gas. The car wouldn't even idle unless it was warming up.

Bump for you. Good luck.

 

Perplexing. Plug the computer in and check it out. I would have suggested a pressure leak. Maybe just for fun do a boost leak test? You said full throttle was ok so maybe not.

 

Well I checked that as well and it's still on there good. When I plug the laptop up what do I look for in the AEM?

Mine still idles where it's suppose to but doesn't idle so smooth and idles leaner then normal. Also when the engine is cold it would idle for like 5 seconds or so then just cut off.