I have 2004 350z with a Stillen stage 3 supercharger and just installed the HKS DLI II and cleaned out the throttle body. Every once in a while when I'm driving the car starts to idle really rough and the engine shakes. Also, while driving the acceleration is not smooth. The problem comes and goes. I'll be driving for about 15 minutes and all of a sudden it starts to run rough, then 15 minutes later it goes away. I double checked all the connections on the HKS DLI II and everything is correct. Do you think it could be from cleaning out the throttle body? Any help would be appreciated. Thanks.

 

did you disconnect it when cleaning? if so, did you go through the relearning procedure?

 

No, didn't disconnect it. Do you think the cleaner is messing up the sensors?

 

You could try the relearning procedure for the throttle/idle...

 

how do you do that?

 

disconnect the battery for 30 seconds and touch the neg to pos you will probably have to tune again

 

Dont most engine management systems flash the tune into memory so that you can disconnect power for a certain amount of time ?

 

What RPM do you idle at?

Does the problem happen with or without the A/C on, or both?

 

it idles at 750 rpm. problem happens with and w/o the ac on. its weird, the rough idle comes and it goes. car runs good for about 30 minutes then starts to idle rough and run rough for about 15 minutes. I'm going to take the HKS DLI off and see if thats causing the problem. I've already tried resetting the ecu but problem still occurs.

 

Try cleaning the MAF and check for any leaks (ie. loose hose clamps, bolts, etc).

 

Found out the problem. Its the HKS DLI. I took it off and the car ran perfect. Then put it back on to see if would happen again and it did. The car was misfiring badly. So I took it back to Stillen and they gave me a new HKS DLI.