Hello, I have a Honda logo with a D15Z6 swapped into it with a mugen chip. The engine was apparently running perfectly fine prior to the swap.

I’m having multiple issues and I can’t seem to figure it out despite browsing the forums, my issues are;

• Rough idle
• sporadic revving, it will sometimes go very high or very low and stall.
• excessive fuel consumption
• misfire sound without there being any misfire.

I have cleaned out the IAVC, the throttle body and cleaned a number of the sensors. I truly don’t know what else to look at, some of the stuff is beyond me as I’m not a mechanic.

the engine appears to run quite well under load, as soon as I take my foot off the throttle at 2K~ or under when driving it starts to buck/jerk massively.

there also appears to be a strange metallic grinding noise almost like a bearing of some kind however this is intermittent every few seconds.

if anybody could help me that would be greatly appreciated.

 

D15Z6 is a vtec-e motor if I recall. Mugen chip is some random chip for what motor?

I'm willing to bet the Chipped ECU is for a vtec motor not vtec-e.

 

Post the CEL codes stored in the ECU.

Check for a vacuum leak.

Does the engine have an EGR system? If so, clean the carbon from the EGR valve and intake manifold.