high rpm stuttering, help

[sk8freak8989]

my car is having bad stuttering or jerking when im above 4 or 5000 rpm. It almost feels like fuel cut but it does it a couple of times. The car has a big 16g, 680 injectors, a fuel pump out of a vr4 3000gt and i am running a 2g MAF. So far i have done a boost leak test and there are no leaks. I have also checked the base timing and regaped the plugs to .028. The car is useing a keydiver chip and an afc but it is zeroed out. My wideband starts around 14.7 and ends up at 10.9 at WOT. Does anyone know what would fix this problem.

thanks

 

[allwheelsdriven]

My friend who has a 2005 Evo 8 had this same problem at midrange rpm and it was caused by fouled plugs. It seems that anytime you tune your dsm and are running a lot more boost and fuel you start to foul plugs really quick. What i would do is pull them out and see if any of them are more white than the others. That should mean that the plug which is more white is running leaner than the others which is what happened to his number two cylinder for some reason. Change plugs every 3 to 4 thousand and see if that helps.

 

[dsmdeliveryboy]

Or you could try running a step colder plug and check the wires to make sure they aren't arcing out

 

[sk8freak8989]

I did look at the plugs and they didn't look to bad so i just regapped them and put them back in. I think i am going to order some new plugs and wires just to make sure though. Also i have a CEL for the tps sensor is there any way this could be doing this.

 

[steve]

Also i have a CEL for the tps sensor is there any way this could be doing this.

Depending on why your getting the TPS fault code it could.

 

[NightRiderSRT4]

yeah if the engine is getting a misread from the TPS, it will cause some driving issues. which code is it?

 

[sk8freak8989]

its code 14

so i bought a tps off my friend and that fixed all the problems.

 

[steve]

Your old one was likely worn out and making intermittent contact.