92 240sx running rough after engine swap

[wage1975]

just finished putting an engine in a 92 240 and for some reason it runs VERY rough and seems as though it has a rev limit at 2500 rpms......what could cause this?.........never ran into this type of problem before

[blinker_fluid]

2500 means the ecu is in fail safe. The faq and the heavythrottle website cover this pretty well. Most likely culprit is the maf check that out and if it doesn't work out try searching at the top of the page.

[duffman1278]

Try unplugging MAF, see if it idles much better like that, if it continues doing the same thing try swapping out MAFS with a working one.