Idling like its cammed..

[Jiggalude]

Alright, I've been looking for two days and haven't found any concrete answers. First off, the car runs great, when I first start it up, it ildes around 1000rpm. I eliminated all unnecessary vacuum lines today. I also removed the MBC and hooked the wga up directly the the vacuum source. I also boost leak tested it. When I run the car and boost it hits no more than 10 psi, so I know I don't have any leaks. I've got new plugs and wires, gapped at .030. Turbo is stock, fuel system is stock etc. etc. The only thing that isn't is the MAF-T. I have that set with all dip switches down, AUX. set to zero and base at 2, the other 3 are all zeros as well. It really sounds like it's cammed, but I know it's not because I actually turned the idle up by tightening the cable, and after the car was off and I turned it back on, it idled the same, so it's obviously a computer/sensor issue. Also, if I'm driving through my development and going down a slight hill in second gear, the car will buck slightly. Other than this, the car runs great.

No ideas?

 

[richardc475]

Check your timing, it may have skipped and is y you are hearing a different exhaust note.

 

[Gasolinebaptism]

Being low on oil would make the cams more audible.

 

[ThEDrEaMEnDeR]

Check your timing, it may have skipped and is y you are hearing a different exhaust note.

thats exactly what was thinking. an old friend of mines dsm was just a little bit out of time and it sounded cammed from being out of time

 

[Jiggalude]

Wonderful. But if it was out of time wouldn't that make it run like crap? I mean it runs great aside from the timing. Or maybe the person who had it before me adjusted the timing to give it a bit more HP?

Alright, I got home from work this evening and started the car. It idled great, actually a bit high around 2 grand, but that's because I pulled the throttle cable tighter to see if it would idle better. I didn't let it run long, but why would it idle fine on a cold start, but after driving start idling crappy?

 

[ThEDrEaMEnDeR]

Wonderful. But if it was out of time wouldn't that make it run like crap? I mean it runs great aside from the timing. Or maybe the person who had it before me adjusted the timing to give it a bit more HP?

Alright, I got home from work this evening and started the car. It idled great, actually a bit high around 2 grand, but that's because I pulled the throttle cable tighter to see if it would idle better. I didn't let it run long, but why would it idle fine on a cold start, but after driving start idling crappy?

changing the timing wont give you more HP 4g63s are 0 clearance if anything it will bend a valve

 

[steve]

When I run the car and boost it hits no more than 10 psi, so I know I don't have any leaks.

This doesn't tell you anything other than you don't have boost creep or such a huge leak that the turbo can't do anything. If you pressure tested and it held pressure without additional air for 5 mins or more, then you know it's not leaking.


When it's doing this is it running on all cylinders?

 

[Jiggalude]

Yes it certainly seems like it's running on all cylinders. I can't complain about the way it runs, just the way it idles. I start it up cold, and it idles great, I take it for a spin, it comes back and starts to idle like a cammed car.

I'm going to do another boost leak test tomorrow, maybe I have a leak that's making it idle like that. But I really don't think it is, since when I first start the car up it idles fine. Anyone have any ideas aside from timing?