Thread: after swap issues!!

where do i begin, i have 1991 nissan sentra SE-R with a u12 bb motor in it, i have u12 bb ecu running it and using a de maf with jdm 02. the car runs but while idling and trying to rev it won't go past 4200 ish rpm, and when driving it is very choppy till about 2k and then screams to 3k and then cuts out regardless of it i have peddle floored or partial throttle. I HAVE SEARCHED and come to conclusion it is either fuel leak or maf issue.... after further investigation i found a fuel leak! fixed fuel leak and now runs even worse.... The MAF is the last thing i can think of that would be causing it, i have checked vacuum lines and cannot find leak or anything not connected besides line running of the vc that i have a breather on.. the car does not start with turn key, but when pop clutched it starts.. i have a different maf on the way but till then is there anything that i should check or change... i have bkr7e's in it gapped a little high but going to change it when i get a chance. any information is greatly appreciated! i am still continuing to search but still find nothing... thank you in advance!!!

sorry for big a** paragraph!!!
thanks again!

and you running any time of piggyback?
because the maf is the first thing I can think of, because you have a different maf than the ECU is set for...

also, i ripped tps sensor connector from harness end but got new one and put it one wire colors were different but my friend who's a technician for bmw put it on and ensured me it was done correctly, so is there possibility he did that wrong? i'm out of ideas and school starts pretty soon and need the car rnning thanks again !!!!

no no piggy back, just regular bb u12 ecu, all the research i did led me to believe that the u12 computer would work with a de maf...

Get that u12 maf sensor.

Yeah Im pretty sure your gonna need the same maf for the ECU your running. Also the JDM sensors are probably gonna have to stay until you get a new ECU. If it was me Id throw a USDM ecu, maf, and sensors on the car with an SAFC2 and then you can run what maf and injectors (limited to 50% bigger injs) you want.

times eleventy-billion

so until i find a u12 maf i can use the de ecu? i researched and every post i found said i'd be ok with the de maf... i'm gonna throw the de ecu in when i get a chance and triy and fire it up, will keep you updated, thanks for all the great replies!

ok so i took off the bb ecu, and put on the de ecu, and nothings changed car still won't start but haven't tried pop clutching it yet, i put newer couplers on ic piping but i have no way to check for leaks beause car don't start.... so is there anything else i'm overlooking?

ok so took plugs out again and cleaned em and tried and nothing, still crank and no start, put new rotor on there and still nothing, i did compression check w/o ic piping and running 131 across the board.... ive checked every ground every vacuum but still have no idea, running de maf and de ecu now... please someone has to have an idea...