Running it off my old USDM ECU, cars runs ok except thers a small blip between 3k rpm and 3.4k rpm, it seems like theirs some kind of ignition problem or maybe something else, vacuum line, I DUNNO...

Anyone shed some light on what may cause it?

It doesn't always do it, but sometimes it feels like the engine bogs right then then regains itself and has fullpower...


Also to add, I am using the USDM external coil and USDM distrubutor, and aswell the USDM wiring harness. Brand new MSD plug wires, and new bosch +2 platinum plugs... Also brand new NGX o2 sensor...

The injectors are the ones that came with the JDM engine, but as I said im using the USDM harness... Maybe this could be the problem, or possibly a dirty injector... I can just swap out my injectors off my USDM as I know they work fine.
Thanks in advance.

 

Ya ill tell you what causes it. The entire fuel map is different on a JDM motor and a USDM motor. JDM motor has higher compression, hence the few extra horses, and lack of emissions control devices (if its a 96+ ecu you are using) 10:6 compression vs 10:1 = different fuel maps and ignition tables. usally a full swap contains the correct ecu for the application.

 

Yea I figured that MAY be the problem... I know all the data, but I thought it may just be close enough it should be ok... I guess not... Looks like ill have to get a bit of tuning done..

 

yea, little bit of tuning or get a JDM P13 and you should be goood. the .5 difference in compression is acutally a pretty fookin big one.