View Full Version : Need help! s14 sr swap done but will not rev above ~2.5k when in gear, sputters
dwadia
03-15-2008, 10:28 PM
Hi guys, i just had an s14 sr20det swapped into my 1989 240sx. The car starts with no problem and idles reasonably well. It can also rev freely before it's put into gear, but once i actually start driving it the car will not rev above about 2.5k (no tach so that's an estimate). It starts sputtering, breaking up, and bucking at that point, very similar to if it had no MAF connected and it was in limp mode. Compression is 130 in all cylinders. The guy that installed my engine is not sure at this point what the problem is, and i could really use any advice about what to look for. Can this be a wiring issue? Or some sort of non-functioning sensor? A few details that i don't think are relevant but i'll mention anyway: currently no gauges on the cluster work except fuel (i believe the wiring for them wasn't completed). Also, no o2 sensor is connected yet. The engine has no mods at all and is running a stock s14 MAF. I really appreciate any help.
i need tires
03-15-2008, 10:35 PM
have you changed the MAF yet since you kinda have an idea for that being a common problem...
fairladysx_s13
03-15-2008, 10:40 PM
id say that o2 sensor is part of the problem. The comp is prob running on default which is like the choke on a lawnmover. once the computer reads how the air fuel mixture is, it should run better. may be something else also but this is a must do.
dwadia
03-15-2008, 10:49 PM
I originally had the swap done with an s13 MAF, the guy who did the swap then tried another s13 MAF, and then i brought him the proper s14 MAF (though i believe any of them should work, s13 just handles less max air flow). Also, although i made the comparison to running in limp mode, it is not EXACTLY the same as limp mode - when the MAF is completely disconnected it runs even worse!
I agree about the o2, and it's definitely running super-rich, and i will definitely connect it in a couple days (just didn't have a connecter with me at the time), but i also don't think that would actually prevent it from revving past 2-3k rpm - it would just run like crap but still rev.
mestizo
03-15-2008, 10:50 PM
Yup, O2, MAF or Boost leak. Put an O2 in there first see if it gets better if not check the MAF wiring and look for a boost leak somewhere.
rps13sh
03-15-2008, 11:06 PM
http://srownersclub.com/faq/index.asp#mistakes
dwadia
03-28-2008, 04:09 PM
Sorry i didn't see those last 2 posts. Anyway, the guy who did my swap is now telling me it's running ok. He didn't say it in so many words, but it seems like the MAF was wired incorrectly. I guess i'll see when i look at it myself. Thanks to everyone who posted.
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